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- Front Matter: Volume 9136
- Nonlinear Quantum Optics
- High Power Effects
- Nanophotonics
- Cavity Solitons
- Specialty Fibres
- Applications of Nonlinear Optics
- Fibre Lasers I
- Fibre Lasers II
- Parametric Effects
- Poster Session
- Quantum Optics I
- Quantum Optics II
- Quantum Optics III: Manipulation of Q States of Light
- Quantum Optics IV: Applications
- Poster Session
Front Matter: Volume 9136
Front Matter: Volume 9136
Show abstract
This PDF file contains the front matter associated with SPIE Proceedings Volume 9136, including the Title Page, Copyright information, Table of Contents, Invited Panel Discussion, and Conference Committee listing.
Nonlinear Quantum Optics
Domain-engineered PPLN for entangled photon generation and other quantum information applications
Show abstract
We describe the design and application of domain-engineered, periodically poled lithium niobate (PPLN) for use to
produce entangled photons and for other tools in quantum information and communications. By specially designing and
controlling the PPLN poling pattern, multiple nonlinear optical processes can be simultaneously phasematched. This
capability can be used to generate polarization-entangled photon pairs through type-II spontaneous parametric
downconversion. The single PPLN crystal is designed to produce both the |HV〉 and |VH〉 states where the
downconverted photons are distinguishable by wavelengths, which enables generation of post-selection-free,
polarization-entangled twin photons. We describe the design and fabrication of the PPLN crystal, and initial
experimental results for downconversion of a 775 nm pump to 1532 nm and 1567 nm orthogonally polarized photons.
We also discuss other applications of engineered optical frequency conversion for quantum information including the
use of dual-wavelength upconversion as a beamsplitter to route or analyze photons.
Efficient four-wave mixing by phase-mismatch switching
Show abstract
Nonlinear four-wave-mixing (FWM) interactions enable a wide variety of photonic functionalities, including wave- length conversion, all-optical switching, signal regeneration, and generation of entangled photons. To achieve efficient FWM interactions the waves either have to be phase-matched, or a quasi-phase-matching (QPM) scheme has to be realized. However, these techniques conventionally require light-guiding media with specific characteristics. We propose a more general QPM scheme for enabling efficient FWM interactions in the presence of a large phase-mismatch. The scheme is based on increasing the distance over which there is FWM gain, while simultaneously decreasing the distance over which there is FWM loss. This is achieved by adiabatically alternating between two phase-mismatch values along the propagation path. We discuss in detail how such phase-mismatch switching (PMS) can be employed to achieve QPM of a FWM process, what the requirements are for optimal FWM efficiency, and how the scheme is impacted by nonlinear dispersion as well as optical losses. Additionally, we describe how QPM by PMS can be implemented with a silicon-on-insulator strip waveguide of which the width is adiabatically varied between two values along the propagation path. By means of numerical simulations, we show that such a waveguide can enhance the wavelength conversion by 20 dB after 1 cm compared to a corresponding constant-width waveguide. For a pump wavelength of 1550 nm, PMS enables efficient conversion (> -21 dB) around a target signal wavelength situated anywhere in the entire near-infrared wavelength domain of 1300-1900 nm.
Indirect transitions of a signal interacting with a moving refractive index front
Michel Castellanos Muñoz,
Alexander Yu. Petrov,
Liam O’Faolain,
et al.
Show abstract
The dynamic manipulation of light can be achieved by the interaction of a signal pulse propagating through or reflected
from a refractive index front. Both the frequency and the wave vector of the signal are changed in this case, which is
generally referred to as an indirect transition. We have developed a theory to describe such transitions in integrated
photonic crystal waveguides. Through indirect transitions, the following effects can be envisaged: large frequency shifts
and light stopping and order of magnitude pulse compression and broadening without center frequency shift. All effects
can be potentially realized with a refractive index modulation as small as 0.001.
For the experimental realization, we have used slow light photonic crystal waveguides in silicon. The refractive index
front was obtained by free carriers generation with a switching pulse co-propagating with the signal in the same slow
light waveguide. The group velocities of the signal and the front could be varied arbitrarily by choosing the right
frequencies of the signal and switching pulses. The indirect transition was unambiguously demonstrated by considering
two situations: a) the front overtaking the signal and b) the signal overtaking the front. In both cases, a blue shift of the
signal frequency was observed. This blue shift can only be explained by the occurrence of the expected indirect
transition and not by a direct transition without wave vector variation.
High Power Effects
Longitudinal mode-filling to cancel SBS in fully-fibered MOPAs dedicated to the production of high-energy nanosecond pulses
Show abstract
We present a comprehensive experimental study of the technique of Longitudinal Mode Filling (LMF) applied to the
reduction of Stimulated Brillouin Scattering (SBS), in Ytterbium Doped Fibre Amplifiers (YDFA) at the wavelength of
1064 nm. Pulse durations and Mode Field Diameters (MFD) lie in the ranges of 10 - 100 ns and 10 - 35 μm,
respectively. Input pulse-shaping is implemented by means of direct current modulation in multimode Laser-Diode
seeds. This evidences a number of interests in the development of robust and low cost Master Oscillator Power
Amplifiers (MOPA). Highly energetic, but properly shaped, nanosecond pulses may be produced this way without any
need of additional electro-optical means for in-line phase and amplitude modulation. Seeds consist of Distributed Feed-
Back (DFB) and Fibre Bragg Gratings (FBG) with different fibre lengths. We demonstrate the benefit of LMF with
properly controlled mode spacing, in combination with chirp effects due to fast current transients in the semiconductors,
in order to deal with SBS thresholds in the range of a few to some hundred μJ. The variations of the SBS threshold are
discussed versus the number of longitudinal modes, the operating conditions of the selected seed and pulse-shaping
conditions.
Laser-induced microwave generation with nonlinear optical crystals
Show abstract
We report about a novel technique to generate microwave radiation by the irradiation of a nonlinear optical crystal with
uniformly spaced, ultrashort optical pulses delivered by a mode-locked laser. We study systematically the laser polarization
and intensity dependence of the microwave signal to conclusively show that it is a nonlinear phenomenon and that it
originates from optical rectification. The measurements have been conducted using KTP, LBO and ZnSe crystals.
The observed pulsed microwave signals are harmonically related to the laser pulses repetition rate, a feature that can be
exploited to develop an innovative ultrafast laser detector.
Nanophotonics
High-yield second-harmonic generation from mid-infrared to near-infrared regions in silicon-organic hybrid plasmonic waveguides
Show abstract
An efficient phase-matched second harmonic generation (SHG) process induced in a silicon-organic hybrid plasmonic waveguide
with a thin nonlinear polymer layer deposited on top of a silicon slab and covered by a metal cap is theoretically
proposed. Owing to the hybridization property of the waveguide modes, the SHG from mid-infrared (~ 3.1 μm) to near-infrared
wavelength (~ 1.55 μm) is achieved with small fabrication-error sensitivity and large bandwidth. The SHG efficiency
is predicted up to 8.8% for a low pumping power of 100 mW.
All-optical generation of surface acoustic waves in a silica optical microwire
Show abstract
We demonstrate experimentally and numerically the generation of a new class of surface acoustic waves in a
subwavelength-diameter silica microwire and term this new effect as surface acoustic wave Brillouin scattering
(SAWBS).
Opportunities for Raman wavelength conversion with silicon microdisks
Show abstract
In this paper, we numerically demonstrate the promise of silicon microdisks for Raman Stokes/anti-Stokes wavelength conversion. We design a silicon microdisk suitable for Raman wavelength conversion with “automatic” quasi-phase matching. We show that with this design and with a 2.5% incoupling efficiency for the pump and Stokes input, we can theoretically achieve wavelength conversion efficiencies up to 3.2 dB at input pump powers as low as 7.8 mW. Regarding fabrication tolerances of the design, we find that small deviations from the optimal cross coupling coefficient and from the condition for “automatic” quasi-phase matching are allowed without deteriorating the wavelength conversion efficiency.
Cavity Solitons
Spatio-temporal stability of 1D Kerr cavity solitons
Show abstract
The Lugiato-Lefever equation (LLE) has been extensively studied since its derivation in 1987, when this meanfield
model was introduced to describe nonlinear optical cavities. The LLE was originally derived to describe a
ring cavity or a Fabry-Perot resonator with a transverse spatial extension and partially filled with a nonlinear
medium but it has also been shown to be applicable to other types of cavities, such as fiber resonators and
microresonators.
Depending on the parameters used, the LLE can present a monostable or bistable input-output response
curve. A large number of theoretical studies have been done in the monostable regime, but the bistable regime
has remained widely unexplored. One of the reasons for this was that previous experimental setups were not able
to works in such regimes of the parameter space. Nowadays the possibility of reaching such parameter regimes
experimentally has renewed the interest in the LLE.
In this contribution, we present an in-depth theoretical study of the different dynamical regimes that can
appear in parameter space, focusing on the dynamics of localized solutions, also known as cavity solitons (CSs).
We show that time-periodic oscillations of a 1D CS appear naturally in a broad region of parameter space. More
than this oscillatory regime, which has been recently demonstrated experimentally,1 we theoretically report on
several kinds of chaotic dynamics. We show that the existence of CSs and their dynamics is related with the
spatial dynamics of the system and with the presence of a codimension-2 point known as a Fold-Hopf bifurcation
point. These dynamical regimes can become accessible by using devices such as microresonators, for instance
widely used for creating optical frequency combs.
Strong nonlocal interaction stabilizes cavity solitons with a varying size plateau
Show abstract
Cavity solitons are localized light peaks in the transverse section of nonlinear resonators. These structures are usually formed under a coexistence condition between a homogeneous background of radiation and a self- organized patterns resulting from a Turing type of instabilities. In this issue, most of studies have been realized ignoring the nonlocal effects. Non-local effects can play an important role in the formation of cavity solitons in optics, population dynamics and plant ecology. Depending on the choice of the nonlocal interaction function, the nonlocal coupling can be strong or weak. When the nonlocal coupling is strong, the interaction between fronts is controlled by the whole non-local interaction function. Recently it has shown that this type of nonlocal coupling strongly affects the dynamics of fronts connecting two homogeneous steady states and leads to the stabilization of cavity solitons with a varying size plateau. Here, we consider a ring passive cavity filled with a Kerr medium like a liquid crystal or left-handed materials and driven by a coherent injected beam. We show that cavity solitons resulting for strong front interaction are stable in one and two-dimensional setting out of any type of Turing instability. Their spatial profile is characterized by a varying size plateau. Our results can apply to large class of spatially extended systems with strong nonlocal coupling.
Specialty Fibres
Controlling modulation instability using an incoherent low amplitude seed
Show abstract
We use a continuous-wave low power incoherent seed to control spontaneous modulation instability (MI) in a highly-nonlinear
optical fiber. We show both experimentally and numerically that spectral and noise properties of MI can be
accurately controlled provided the spectral characteristics of the seed are chosen carefully. Specifically, we evidence the
strong influence of the seed coherence on the output pulses signal-to-noise ratio and bandwidth. Stochastic nonlinear
Schrödinger equation simulations are in excellent agreement with experiments.
Tunable stimulated Brillouin scattering in hybrid polymer-chalcogenide tapered fibers
Show abstract
We investigate Brillouin scattering in hybrid As2Se3 PMMA tapered fiber and demonstrate that Brillouin
frequency shift can be widely tuned over a broad radio-frequency range by varying the core diameter of the
optical tapered fiber.
Normal dispersion modulation instability in an As2Se3 chalcogenide hybrid microwire
Show abstract
We use hybrid polymer-chalcogenide optical microwires to realize mid-infrared frequency conversion via the process of
normal dispersion modulation instability (MI). Phase-matching is achieved through a negative fourth-order dispersion
coefficient and leads to the apparition of parametric sidebands located at 2 μm and 3.5 μm, corresponding to a frequency
shift of 30 Thz relative to the pump, which is among the largest reported using normal-dispersion pumped MI in a singlepass
configuration in the mid-IR Stochastic nonlinear Schrödinger equation simulations are in excellent agreement with
experiments.
Temporal localized structures in a photonic crystal fiber resonator
Show abstract
We investigate analytically and numerically the effect of the higher order dispersion on the dynamic of a photonic crystal fiber resonator pumped continuously by a coherent injected beam. The linear stability analysis shows that the fourth order dispersion bounds the zone of modulation instability between two pump power levels and predict a motion of solution induced by the broken symmetry mediated by the third order dispersion. We perform a weakly non linear analysis on the vicinity of the first threshold associated with modulation instability. The amplitude and the non linear correction of velocity of periodic structures are estimated. This analysis allowed us to determine the threshold of apparition of bright localized structures and we have also shown that dark localized structures can be stabilized on the neighborhood of the second threshold of modulation instability. Numerical solutions of the governing equations are in close agreement with analytical predictions.
Applications of Nonlinear Optics
Airy beams propagation in optically induced photonic lattices
Show abstract
We show both experimentally and numerically, control over the acceleration of two-dimensional Airy beam propagating
in optically induced photonic lattice. Varying the lattice strength and including various defects we can reach a state,
where the acceleration is completely stopped. We find an additional class of discrete lattice beams, localized and defect
modes observed with Airy beams propagating in diamond optically induced photonic lattice.
Parallel generation of fast random bits based on optoelectronic phase-chaos systems
Show abstract
We model the performance of an optoelectronic phase-chaos system operating with telecom components to generate random bits. The key component of the system is differential delay, namely the system is subject to two delay times which differ in an amount much larger than the autocorrelation time. This is implemented by a delay loop and an imbalanced Mach-Zhender modulator. We show that after suitable digitalization of the chaotic signal the generated bits pass all the NIST test for randomness. We also show that the system can be extended to have several chains in parallel each with a Mach-Zhender modulator, each chain being used to produce a sequence of random bits. If the differential delays of the Mach-Zhenders differ by an amount larger than the autocorrelation time of the chaotic dynamics, the output of the different chains is uncorrelated and therefore can be used for parallel generation of statistically independent random bit-streams. In addition, we also find that a sequence constructed by interleaving the parallel bit-streams also pass all the NIST tests for randomness. Based on the least significant bits which can be included in the sequence and the number of the parallel branches which can be implemented, we show that bit rates up to Tb/s can be achieved.
Fibre Lasers I
High-power femtosecond fiber lasers based on self-similar pulse evolution
Show abstract
The status of femtosecond fiber lasers based on self-similar evolution of parabolic pulses will be reviewed,
and ongoing efforts to generate few-cycle pulses from fiber lasers will be described.
Vector solitons in harmonic mode-locked erbium-doped fiber lasers
Show abstract
We report experimental study of vector solitons for the fundamental and harmonic mode-locked operation in erbiumdoper
fiber lasers with carbon nanotubes based saturable absorbers and anomalous dispersion cavities. We measure
evolution of the output pulses polarization and demonstrate vector solitons with various polarization attractors, including
locked polarization, periodic polarization switching, and polarization precession.
Self-similar pulse-shape mode for femtosecond pulse propagation in medium with resonant nonlinearity
Show abstract
We investigate the mode of laser pulse propagation in homogeneous medium with resonant nonlinearity, at which the
shape of pulse is self-similar one along some distance of propagation. We take into account a laser pulse frequency
detuning from resonant frequency. Both types of sign for frequency detuning are considered. This results in appearance
of a refractive index grating which induced self-action of a laser pulse.
I certain cases we develop analytical solution of corresponding nonlinear eigenfunction problem of laser pulse
propagation in medium for multi-photon resonance. This solution is confirmed by computer simulation of an
eigenfunction problem for Schrödinger equation with considered nonlinearity.
Using computer simulation, one shows a validity of existence of such kind of laser pulse propagation in a medium with
resonant nonlinear response.
Fibre Lasers II
Nonlinear energy deposition in water from fs-laser pulses: effect of the input chirp
Show abstract
We present numerical and experimental investigation of the effect that the input pulse chirp has on the energy transfer from 5 μJ fs-pulses at 800 nm to water. The chirp is seen to control efficiently the energy transfer and the geometrical properties of the excited plasma volumes. Agreement between simulations and experiments is obtained via a parametric study, the details of which are presented here. These results may find applications in the control of underwater bubble and sound wave formation, and also in laser surgery involving aqueous media.
Nonlinear mixing and mode correlations in a short Raman fiber laser
Show abstract
In the present paper we experimentally demonstrate a generation in a short Raman fiber laser having 10 000 different
longitudinal modes only. We design the laser using 12 meters of commercially available fiber. Contrary to the recently
demonstrated single longitudinal mode DFB Raman laser and short DBR Raman laser, in the laser under study the
number of modes is high enough for efficient nonlinear interactions. Experimentally measured time dynamics reveals the
presence of mode correlations in the radiation: the measured extreme events lasts for more than 10 round-trips.
Influence of the generated power, measurement bandwidth, and noise level on intensity statistics of a quasi-CW Raman fiber laser
Show abstract
In the present paper we numerically study instrumental impact on statistical properties of quasi-CW Raman fiber laser
using a simple model of multimode laser radiation. Effects, that have the most influence, are limited electrical bandwidth
of measurement equipment and noise. To check this influence, we developed a simple model of the multimode quasi-
CW generation with exponential statistics (i.e. uncorrelated modes). We found that the area near zero intensity in
probability density function (PDF) is strongly affected by both factors, for example both lead to formation of a negative
wing of intensity distribution. But far wing slope of PDF is not affected by noise and, for moderate mismatch between
optical and electrical bandwidth, is only slightly affected by bandwidth limitation. The generation spectrum often
becomes broader at higher power in experiments, so the spectral/electrical bandwidth mismatch factor increases over the
power that can lead to artificial dependence of the PDF slope over the power. It was also found that both effects
influence the ACF background level: noise impact decreases it, while limited bandwidth leads to its increase.
Parametric Effects
Sensitive terahertz-wave detector using a quasi-phase-matched LiNbO3 at room temperature
K. Nawata,
T. Notake,
H. Ishizuki,
et al.
Show abstract
Sensitive terahertz (THz)-wave sensor at room temperature is crucial for most applications such as 2-dimensional realtime
imaging and nonlinear phenomena in semiconductors caused by multi-photon absorption, light-induced ionization,
and saturated absorption. LiNbO3 is a promising material for frequency up- and down-conversion because of its high
nonlinearity and high resistance to optical damage. In this report, we propose a slant-stripe-type periodically poled Mg
doped LiNbO3 (PPMgLN) crystal for the construction of a practical THz detector. The PPMgLN solves compromised
optical design and low coupling efficiency between THz and infrared (IR) pump beam due to imperfect dichroic coupler.
The effective coupling of both pump beam and THz-wave into identical interaction region of up-conversion device
promotes the THz detector in practical use. The phase-matched-condition in slant-stripe-type PPMgLN was designed to
offer collinear propagation of two optical waves, the pump and up-conversion signal beams, because of efficient
frequency conversion. The phase-mached-condition was calculated and a slant-stripe-type PPMgLN with an angle (α) of
20° and a grating period (Λ) of 29.0 μm was used in this experiment. A minimum detectable energy of 0.3 pJ/pulse at the frequency of 1.6 THz was achieved with the pump energy of 1.8 mJ/pulse in room temperature. The dynamic range of the incident THz-wave energy of 60 dB was demonstrated. Further improving for the sensitivity using longer interaction
length in a PPMgLN crystal was also investigated.
2.6 um to 12 um tunable ZGP parametric master oscillator power amplifier
Show abstract
We present a widely tunable mid infrared coherent light source based on a tandem optical parametric oscillator (OPO)
and subsequent optical parametric amplification (OPA). The output wavelengths can be seamlessly tuned in the Mid-IR
from 2.6 μm to 12 μm or 4000 cm-1 to 833 cm-1 respectively. Maximal output energy of 26 mJ was obtained at a wavelength of 4.25 μm.
Poster Session
Field-enhanced nonlinear optical properties of organic nanofibers
Show abstract
Second harmonic generation in nonlinearly optically active organic nanofibers, generated via self-assembled surface
growth from nonsymmetrically functionalized para-quarterphenylene (CNHP4) molecules, has been investigated. After
the growth on mica templates, nanofibers have been transferred onto lithographically defined regular arrays of metal and
dielectric nanostructures. Such hybrid systems were employed to correlate the second harmonic response to both
morphology of the fibers i.e. local field enhancement due to local changes in the fiber’s morphology and field
enhancement effects appearing on the nanostructures. With the help of femtosecond laser scanning microscopy two-dimensional
second-harmonic images of individual nanoaggregates were obtained and analyzed.
Multi-modes of four-waves mixing at non-collinear interaction of laser beams in medium with cubic nonlinear response
Show abstract
We develop an explicit solution of problem describing collinear four-waves mixing in medium with cubic nonlinear
response. This solution is carried out for set of Schrödinger equations using plane wave approximation for the case of
phase matching for interacting waves. This solution allows to do full analysis of four-wave interaction modes in
dependence of the problem parameters.
We have shown, in particular, an existence of bistable mode for energy conversion from pump waves to signal wave
under certain conditions. In general case, there are greater than 10 various modes of four-wave interaction.
Knowledge about these modes is very important for spectroscopic experiment results understanding using four-waves
mixing because its result depends on them in strong way. Analytical solutions and derived modes can explain
complicated regime of four-wave interaction which may be appeared at high intensity of interacting waves.
Control of soliton pattern through continuous external injection
Show abstract
The effect of an external continuous wave (cw) on the operating regime of a passively mode-locked double-clad fiber
laser, operating in the anomalous dispersion regime, is experimentally investigated. Starting from different soliton
distributions, we demonstrate that, under specific conditions, the cw signal forces the principal laser to operate in
harmonic mode-locking regime.
Instantaneous frequency measurement of microwave signals in optical range using “frequency-amplitude” conversion in the π-phase-shifted fiber Bragg grating
Show abstract
This paper presents a microwave photonics method for the instantaneous frequency measurement of microwave signals,
based on the generation of a two-frequency laser radiation in the Mach-Zehnder modulator with a difference frequency
equal to the measured, and the "frequency - amplitude" conversion in the π-phase-shifted fiber Bragg grating. Frequency
measurement occurs in two ranges: 0.3 - 3 GHz in the passband of the FBG and 3 - 30 GHz in its reflection band. Using
the specific conversion of two-frequency radiation in the π-phase-shifted fiber Bragg grating allowed us to obtain measuring
characteristics, that are independent of the amplitude fluctuations of the optical carrier and to organize additional
circuit for monitoring the spectral characteristics of the used elements to reduce measurement inaccuracy caused by their
temperature instability.
Engaging new dimensions in nonlinear optical spectroscopy using auxiliary beams of light
Show abstract
By applying a sufficiently intense beam of off-resonant light, simultaneously with a conventional excitation source beam,
the efficiencies of one- and two-photon absorption processes may be significantly modified. The nonlinear mechanism
that is responsible, known as laser modified absorption, is fully described by a quantum electrodynamical analysis. The
origin of the process, which involves stimulated forward Rayleigh-scattering of the auxiliary beam, relates to higher
order terms which are secured by a time-dependent perturbation treatment. These terms, usually inconsequential when a
single beam of light is present, become prominent under the secondary optical stimulus – even with levels of intensity
that are moderate by today’s standards. Distinctive kinds of behaviour may be observed for chromophores fixed in a
static arrangement, or for solution- or gas-phase molecules whose response is tempered by a rotational average of
orientations. In each case the results exhibit an interplay of factors involving the beam polarisations and the molecular
electronic response. Special attention is given to interesting metastable states that are symmetry forbidden by one- or
two-photon absorption. Such states may be accessible, and thus become populated, on input of the auxiliary beam. For
example, in the one-photon absorption case, terms arise that are more usually associated with three-photon processes,
corresponding to very different selection rules. Other kinds of metastable state also arise in the two-photon process, and
measuring the effect of applying the stimulus beam to absorbances of such character adds a new dimension to the
information content of the associated spectroscopy. Finally, based on these novel forms of optical nonlinearity, there
may be new possibilities for quantum non-demolition measurements.
Nonlinear picosecond pulse transformation in large-core microstructured fibers
Show abstract
Our research deals with studying picosecond pulse propagation from ytterbium laser through the large core multimode
microstructured fibers. Fibers with core sizes from 8 μm to 11 μm were investigated. Pumping in the normal dispersion
regime was made. Supercontinuum (SC) spectra were obtained in all the fiber samples. The main mechanism,
particularly four-wave mixing, responsible for SC generation was investigated theoretically.
Investigation of the separate optical nonlinear contributions of the core and cladding materials of silicon photonics slotted waveguides
Show abstract
The nonlinear properties of slotted silicon photonic waveguides filled with third-order nonlinear materials (NM,
DDMEBT polymer) are quantitatively studied by separately calculating the effective nonlinearity susceptibilities
associated to the silicon and cladding material, respectively. Optimization of the silicon slotted waveguide geometry is
performed and focused on the optimization of optical power confinement in the high FOMTPA cladding material and of
Aeff(NM)/Aeff(Si). The simulated nonlinear wave evolution results show the importance of properly choosing the silicon
rail and slot widths in order to minimize the influence of the two-absorption process and associated free carrier effects
(free carrier absorption, free carrier refraction).
Linear electro-optical scattering from ferroelectric nanocrystals
Show abstract
We report on the linear electro-optical scattering response from individual ferroelectric (KTiOPO4) nano-crystals. The newly developed Pockels Linear Electro-Optical Microscopy (PLEOM)1-3 is used in this context to map the second-order susceptibility χ(2) of non-centrosymmetric materials with a high sensitivity due to a stabilized interferometric homodyne detection. The random spatial orientation of single nano-crystals (with an average size of 150 nm), together with the orientation of the electric dipole moment of ferroelectric domains can be jointly inferred from the intensity polarization plots together with phase of the linear electro-optical response. Down- scaling the electro-optic response to nano-crystals opens-up new applications towards sub-diffraction electro-optic nano-labels for nonlinear microscopy with applications to nano-sciences and biophotonics. By using a low power He-Ne laser source and a low intensity illumination beam, PLEOM bears the potential of a new low-cost non-imaging method in biology, especially relevant for sensitive samples.
Effect factors of temperature measurements by femtosecond time-resolved CARS
Yang Zhao,
Sheng Zhang,
Zhibin Zhang,
et al.
Show abstract
Femtosecond time-resolved coherent anti-Stokes Raman spectroscopy is utilized to measure the premixed
methane/oxygen/nitrogen flame temperature at atmospheric-pressure. The procedure for fitting theoretical spectra to
experimental spectra is explained. The experimental results show good agreements with theoretical ones and present a
good repeatability. Laser parameters are very important for accurate temperature measurements. The effects of laser
parameters on temperature measurements are discussed. Laser parameters in our discussion are shown as follows. Laser
pulse shape is hyperbolic secant and Lorentz, respectively. The delay time between the pump and Stokes is from -40 fs to
+40 fs. The central wavelength of the pump/probe pulses is from 650 nm to 700 nm. Pulse duration is from 40 fs to 120
fs. In 2000 K, variations of delay time between the pump and Stokes pulses lead to less than 5% error and while
variations of the other three parameters lead to less than 1.5% error. Timing jitter is added to the pump/probe pulses and
Stokes pulses. In 2000 K, the results indicate that timing jitter of 10% lead to less than 2% error for temperature
measurements. In the higher temperature measurement, the impact of laser parameters’ error is greater.
Proposal of ultra-compact NAND/NOR/XNOR all-optical logic gates
based on a nonlinear 3x1 multimode interference
Show abstract
We present a highly miniaturized multimode interference (MMI) coupler based on nonlinear modal propagation analysis
(NMPA) method as a novel design method and potential application for optical NAND, NOR and XNOR logic gates for
Boolean logic signal processing devices. Crystalline polydiacetylene is used to allow the appearances of nonlinear effects
in low input intensities and ultra- short length to control the MMI coupler as an active device to access light switching
due to its high nonlinear susceptibility. We consider a 10x33 μm2 MMI structure with three inputs and one output.
Notably, the access facets are single-mode waveguides with sub-micron width. The center input contributes to control
the induced light propagation in MMI by intensity variation whereas others could be launched by particular intensity
when they are ON and 0 in OFF. Output intensity is analyzed in various sets of inputs to show the capability of Boolean
logic gates, the contrast between ON and OFF is calculated on mentioned gates to present the efficiency. Good operation
in low intensity and highly miniaturized MMI coupler is observed. Furthermore, nonlinear effects could be realized
through the modal interferences. The issue of high insertion loss is addressed with a 3×3 upgraded coupler. Furthermore,
the main significant aspect of this paper is simulating an MMI coupler that is launched by three nonlinear inputs,
simultaneously, whereas last presents have never studied more than one input in nonlinear regimes.
Influence of photonic crystal fiber manufacturing inaccuracies on supercontinuum generation
Show abstract
We investigate a change of dispersion characteristic in a series of nonlinear photonic crystal fibers caused by slight
variation of structural parameters, i.e. an air-hole diameter and a lattice constant. Each fiber has been fabricated to have
zero dispersion wavelength close to 1064 nm. The generation of supercontinuum is also demonstrated with the use of
fabricated fibers pumped at the wavelength of 1064 nm. We provide the comparison of SC evolution and different
nonlinear effects in fabricated fibers. Due to the extensive content of experimental research performed for different
photonic crystal fibers, our paper indicates how to design a fiber to be tolerant to the fabrication inaccuracies and to
obtain the desired supercontinuum characteristics.
Experimental demonstration of all optical XOR and XNOR gates for differential phase modulated data
Show abstract
All optical logic gates play a key role in implementing an optically transparent network where the node functionalities
are performed in the optical domain to reduce latency and power consumption. In this paper we present the experimental
demonstration and details of optimization of all optical XOR/ XNOR gate using four-wave mixing (FWM) in
Semiconductor Optical Amplifier (SOA) for 10 Gbps Differential Phase Shift Keyed (DPSK) data.
Two DPSK modulated signals at carrier frequencies ω1 and ω2, phases ϕ1and ϕ2and a continuous wave pump at
frequency ωCW and phase ϕCW are allowed to undergo FWM in a non-linear SOA to generate additional frequency
components. The phase of the generated FWM idler corresponding to the frequency ω1+ ω2-ωCW given by ϕ1+ ϕ2- CW
corresponds to the XOR operation in DPSK format. Light from a DFB and tunable laser source (TLS) are combined and
phase-modulated using a pseudo-random bit sequence. The bit sequences in the two carrier wavelengths are separated in
time by propagating through a sufficient length of SMF; the data is combined with a CW pump from a tunable laser and
allowed to undergo non-degenerate FWM in a nonlinear SOA. The relative spacing between the pump and the signal
wavelengths and their polarization states are optimized to yield maximum conversion efficiency in the desired idler. The
XOR output is further propagated through a delay-line interferometer (DLI) to obtain XOR and XNOR outputs in the
two ports of the DLI, in the OOK format. Extinction ratio and Contrast ratio of better than 7.2 dB and 10.6 dB
respectively for the XNOR gate and 6.8 dB and 7.5 dB for the XOR gaterespectively.
Cross-absorption as a limit to heralded silicon photon pair sources
Show abstract
In recent years integrated waveguide devices have emerged as an attractive platform for scalable quantum tech- nologies. In contrast to earlier free-space investigations, one must consider additional effects induced by the media. In amorphous materials, spontaneous Raman scattered photons act as a noise source. In crystalline materials two-photon absorption (TPA) and free carrier absorption (FCA) are present at large intensities. While initial observations noted TPA affected experiments in integrated semiconductor devices, at present the nuanced roles of these processes in the quantum regime is unclear. Here, using single photons generated via spontaneous four-wave mixing (SFWM) in silicon, we experimentally demonstrate that cross-TPA (XTPA) between a classical pump beam and generated single photons imposes an intrinsic limit on heralded single photon generation, even in the single pair regime. Our newly developed model is in excellent agreement with experimental results.
NLSE-based model of a random distributed feedback fiber laser
Show abstract
In this work we propose a NLSE-based model of power and spectral properties of the random distributed feedback
(DFB) fiber laser. The model is based on coupled set of non-linear Schrödinger equations for pump and Stokes waves
with the distributed feedback due to Rayleigh scattering. The model considers random backscattering via its average
strength, i.e. we assume that the feedback is incoherent. In addition, this allows us to speed up simulations sufficiently
(up to several orders of magnitude). We found that the model of the incoherent feedback predicts the smooth and narrow
(comparing with the gain spectral profile) generation spectrum in the random DFB fiber laser. The model allows one to
optimize the random laser generation spectrum width varying the dispersion and nonlinearity values: we found, that the
high dispersion and low nonlinearity results in narrower spectrum that could be interpreted as four-wave mixing between
different spectral components in the quasi-mode-less spectrum of the random laser under study could play an important
role in the spectrum formation. Note that the physical mechanism of the random DFB fiber laser formation and
broadening is not identified yet. We investigate temporal and statistical properties of the random DFB fiber laser
dynamics. Interestingly, we found that the intensity statistics is not Gaussian. The intensity auto-correlation function also
reveals that correlations do exist. The possibility to optimize the system parameters to enhance the observed intrinsic
spectral correlations to further potentially achieved pulsed (mode-locked) operation of the mode-less random distributed
feedback fiber laser is discussed.
Multipolar nonlinear light-matter interactions with Gaussian vector beams
Show abstract
We show that surface second-harmonic generation (SHG) with focused Gaussian vector beams can be described in terms
of effective Mie-type multipolar contributions to the SHG signal even in the electric dipole approximation of constitutive
relations. Traditionally, Mie-type multipoles arise from field retardation across nanoparticles. In our case, the multipolar
light-matter interaction is due to excitation with Gaussian vector beams and the tensorial properties of the SH response.
As different multipoles have different radiative properties, we demonstrate the presence of multipoles by measuring
strongly asymmetric SH emission into reflected and transmitted directions from a nonlinear thin film with isotropic
surface symmetry, where symmetric emission is expected using traditional formalisms based on plane-wave excitation.
The proposed multipole approach provides a convenient way to explain the measured asymmetric emission. Secondly,
we generalize the treatment beyond the electric dipole approximation and propose that analogous vector excitation-induced
multipolar effects could also occur in the microscopic light-matter interaction. Our results may allow new
possibilities to designing confined and thin nonlinear sources with desired radiation patterns.
Delay-based reservoir computing using semiconductor ring lasers
Show abstract
Delay systems subject to delayed optical feedback have recently shown great potential in solving computationally
hard tasks. By implementing a neuro-inspired computational scheme relying on the transient response to optical
data injection, high processing speeds have been demonstrated. However, reservoir computing systems based on
delay dynamics discussed in the literature are designed by coupling many different stand-alone components which
lead to bulky, lack of long-term stability, non-monolithic systems. Here we numerically investigate the possibility
of implementing reservoir computing schemes based on semiconductor ring lasers as they are scalable and can
be easily implemented on chip. We numerically benchmark our system on a chaotic time-series prediction task.
Spatial extreme events in a photorefractive single-feedback system
Show abstract
We analyze pattern formation in an optical system composed of a bulk photorefractive crystal subjected to a single
optical feedback. Far above the modulational instability threshold, in a highly nonlinear regime we report on a turbulent
spatio-temporal dynamics that leads to rare and intense localized optical peaks. We demonstrate that the statistics and
features of those peaks correspond to two dimensional rogue events. These optical rogue waves arise erratically in space
and time and live for a typical time of the same order of the response time of the photorefractive material.
Modeling Kerr frequency combs using the Lugiato-Lefever equation: a characterization of the multistable landscape
Show abstract
Optical frequency combs can be used to measure light frequencies and time intervals more easily and precisely
than ever before, opening a large avenue for applications. Traditional frequency combs are usually associated
with trains of evenly spaced, very short pulses. More recently, a new generation of comb sources has been
demonstrated in compact high-Q optical microresonators with a Kerr nonlinearity pumped by continuous-wave
laser light. These combs are now referred to as Kerr frequency combs and have attracted a lot of interest in the
last few years.
Kerr frequency combs can be modeled in a way that is strongly reminiscent of temporal cavity solitons (CSs)
in nonlinear cavities. Temporal CSs have been experimentally studied in fiber resonators and their description
is based on a now classical equation, the Lugiato-Lefever equation, that describes pattern formation in optical
systems.
In this work, we first perform a theoretical study of the correspondence between the CSs and patterns with
frequency combs. It is known that the CSs appear in reversible systems that present bistability between a
pattern and a homogeneous steady state through what it is called a homoclinic snaking structure. In this
snaking region, single and multi-peak CSs coexist with patterns and homogeneous solutions, creating a largely
multistable landscape. We study the changes of the homoclinic snaking for different parameter regimes in the
Lugiato-Lefever equation and determine the stability and shape of the frequency combs through comparison with
the underlying CSs and patterns. Secondly, we include third order dispersion in the system and study its effect
on the multistable snaking structure. For high dispersion strengths the CS structures and the corresponding
Kerr frequency combs disappear.
Synthetic diamond as a new material for on-chip nonlinear wavelength converters
Show abstract
The emergence of synthetic diamond has enabled photonics researchers to start exploiting the unique optical properties of diamond for various applications. In this paper we numerically predict the performance of
diamond ring waveguide structures for nonlinear wavelength conversion. After examining to what extent both
dispersion-engineered phase-matching and “automatic” quasi-phase-matching can be established in diamond ring
converters, we show that these phase matching approaches can yield high conversion efficiencies for a wide range
of wavelengths in the near-infrared/mid-infrared domain, as well as in the ultraviolet/visible domain.
Self-action effects in semiconductor quantum dots
V. S. Dneprovskii,
A. R. Kanev,
M. V. Kozlova,
et al.
Show abstract
Two-dimensional (2D) dynamic photonic crystal regime has been utilized to investigate self-diffraction effect and
nonlinear optical properties of excitons in CdSe/ZnS colloidal quantum dots (QDs). Self-diffraction at 2D photonic
crystal arises for three intersecting beams of Nd+3:YAG laser second harmonic in the case of one-photon resonant
excitation of the exciton (electron - hole) transition QDs. The relaxation time of excited excitons has been measured by
pump and probe technique at induced one-dimensional transient diffraction grating. Two-exponential decay with initial
fast and slow parts was discovered. Self-action effect has been discovered in the case of stationary resonant excitation of
excitons in CdSe/ZnS QDs by the beam of second harmonic of powerful 12-nanosecond laser pulses. The bleaching of
exciton absorption and the creation of transparency channel (this effect provokes self-diffraction of the second harmonic
beam) was explained by the dominating coexisting and competing processes of state filling in stationary excited quantum
dots and Stark-shift of exciton spectral band. The peculiarities of the influence of these processes at the change of
exciton absorption in quantum dots in the case of different detuning from exciton resonance (quantum dots with different
size have been used) was analyzed.
Electrical nonlinear response of a photomixer for applications in ultrafast measurements
Florin L. Constantin
Show abstract
Electrical nonlinear response of a low-temperature-grown GaAs photomixer is exploited for THz-wave modulation,
detection and waveform sampling. Current-voltage response at low bias field is modelled by electron drift velocity
saturation. THz-wave rectification is discussed in a small-signal approximation and experimentally addressed in
connection with the curvature of IV plot. The optical heterodyne signal from two lasers down-converted with the
photomixer is modulated by applying an alternative bias field. Conversely, heterodyne detection of a continuous-wave
THz source is demonstrated with the photomixer using the optical beat between the lasers as local oscillator.
Alternatively, THz-waves with tunable carrier and pulse repetition rate are generated with a THz frequency multiplier
driven by a pulsed microwave synthesizer. Asynchronous optical sampling with a pulsed optical beat is demonstrated
with the heterodyne detection scheme.
Quantum Optics I
High performing SPS based on native NIR-emitting single colour centers in diamond
Show abstract
Single-photon sources (SPS) play a key-role in many applications, spanning from quantum metrology, to quantum information and to the foundations of quantum mechanics. Even if an ideal SPS (i. e. emitting indistinguishable, ”on-demand” single photons, at an arbitrarily fast repetition rate) is far to be realized due to real-world deviations from the ideality, much effort is currently devoted to improving the performance of real sources. With regards to the emission probability, it appears natural to employ sources that are in principle deterministic in the single- photon emission (single quantum emitters such as single atoms, ions, molecules, quantum dots, or color centers in diamond) as opposed to probabilistic ones (usually heralded SPS based on parametric down-conversion). We present an overview of our latest results concerning a work-in-progress NIR pulsed single photon source based on single quantum emitters (color centers in diamond) exploiting recently reported centers. They are particularly interesting because of the narrow emission line (tipically less than 5 nm), the shorter excited state lifetime with respect to NV centres (1 - 2 ns compared to 12 ns, allowing a ten-fold photon emission rate upon saturation) and the polarized emission.
Optimized QKD BB84 protocol using quantum dense coding and CNOT gates: feasibility based on probabilistic optical devices
Show abstract
In this work, we simulate a fiber-based Quantum Key Distribution Protocol (QKDP) BB84 working at the telecoms wavelength 1550 nm with taking into consideration an optimized attack strategy. We consider in our work a quantum channel composed by probabilistic Single Photon Source (SPS), single mode optical Fiber and quantum detector with high efficiency. We show the advantages of using the Quantum Dots (QD) embedded in micro-cavity compared to the Heralded Single Photon Sources (HSPS).
Second, we show that Eve is always getting some information depending on the mean photon number per pulse of the used SPS and therefore, we propose an optimized version of the QKDP BB84 based on Quantum Dense Coding (QDC) that could be implemented by quantum CNOT gates.
We evaluate the success probability of implementing the optimized QKDP BB84 when using nowadays probabilistic quantum optical devices for circuit realization. We use for our modeling an abstract probabilistic model of a CNOT gate based on linear optical components and having a success probability of sqrt (4/27), we take into consideration the best SPSs realizations, namely the QD and the HSPS, generating a single photon per pulse with a success probability of 0.73 and 0.37, respectively. We show that the protocol is totally secure against attacks but could be correctly implemented only with a success probability of few percent.
The study of reducing the effect of detector saturation on ghost imaging
Show abstract
The quantum imaging (ghost) has attracted many attention in recent years. In the ghost imaging scheme, the object
information is captured by the “bucket” detector which has no spatial information. In practical scheme, the CCD array or
the APD are utilized as the “bucket” detector, but the saturation effect of the detector may exist due to the limited
sampling depth of the detector. The two methods are presented to reduce the effect of the saturation for different “bucket”
detectors. The method for CCD array is based on the statistic principle of ghost imaging, and the other is based on the
compressed sensing. After that, we compare the difference between the ghost imaging and compressed sensing in the low
light level condition.
Quantum Optics II
Position-dependent photon operators in the quantization of the electromagnetic field in dielectrics at local thermal equilibrium
Mikko Partanen,
Teppo Häyrynen,
Jani Oksanen,
et al.
Show abstract
It has very recently been suggested that asymmetric coupling of electromagnetic fields to thermal reservoirs under nonequilibrium conditions can produce unexpected oscillatory behavior in the local photon statistics in layered structures. Better understanding of the predicted phenomena could enable useful applications related to thermometry, noise filtering, and enhancing optical interactions. In this work we briefly review the field quantization and study the local steady state temperature distributions in optical cavities formed of lossless and lossy media to show that also local field temperatures exhibit oscillations that depend on position as well as the photon energy.
Optical four-wave mixing and generation of squeezed light in an optomechanical cavity driven by a bichromatic field
Rafael Garcés,
Germán J. de Valcárcel
Show abstract
We show that an optomechanical cavity pumped by a bichromatic light beam can generate a signal whose frequency lies
halfway between the two driving frequencies. This process can be understood as a degenerate four-wave mixing, in
which two pump photons (one from each frequency) are combined to yield two identical signal photons. This process
takes place between a lower and an upper threshold in terms of the pump intensity, which depend on the pump frequency
difference. Close to the signal oscillation threshold a clear noise reduction in one of its quadratures is shown numerically.
Quantum information with optical photons in hybrid molecule-superconducting qubit system
Show abstract
We put forward a novel approach for quantum state readout from superconducting qubits and transfer with
optical photons. Our proposal involves a hybrid system of a two-level molecule coupled to a superconducting
qubit. We show that one can achieve strong coupling regime in such hybrid system which can then be harnessed
to study various quantum effects. These includes but are not restricted to optical determination of the qubit
state, entanglement generation, storage and manipulation of quantum information.
Quantum Optics III: Manipulation of Q States of Light
Recovery of qubit coherence by noise-eater technique
Show abstract
We propose a quantum noise eater for a single qubit and experimentally verify its performance for recovery of
a superposition carried by a dual-rail photonic qubit. We consider a case when only one of the rails (e.g., one
of interferometric arms) is vulnerable to noise. A coherent but randomly arriving photon penetrating into this
single rail causes a change of its state, which results in an error in a subsequent quantum information processing.
We theoretically prove and experimentally demonstrate a conditional full recovery of the superposition by this
quantum noise eater.
Slow light in evanescently coupled optical cavities containing quantum dots
Show abstract
Ability to tune the group velocity of a light pulse is of great importance for optical communication applications and
realization of quantum information processing. Tunability of group velocity can be achieved by using either optical or
electronic resonances. Tunability of an optical resonance depends on the change in refractive index of the cavity
material. However, since electro-optical coefficients of non-engineered materials are quite small, the tuning range of
optical resonances by electric field is narrow. This makes tuning by electric field impractical for most applications.
Quantum dot (QD) coupled to a photonic crystal cavity is a useful hybrid system exhibiting nonlinear features. In this
work, we analyze the use of quantum dot - optical cavity hybrid systems to engineer nonlinear waveguides susceptible to
electric fields. We start by theoretically analyzing the optical pulse propagation at low-photon number excitation limit in
a periodically arranged strongly coupled quantum dot - photonic crystal system. A one dimensional periodic array of
evanescently coupled photonic cavities (coupled resonator optical waveguides, CROWs) containing non-interacting
quantum dots allows us to tune the group velocity and the bandwidth of the pulse by adjusting the cavity/QD coupling.
Tunable group velocity can be achieved by applying an external electric field which will result in a significant decrease
in the cavity/QD coupling because of DC Stark effect. We also show that, using this approach, light pulses can be
slowed down or stored by compressing the pulse bandwidth adiabatically and reversibly. Adiabatic bandwidth
compression can be achieved by slowly decreasing the coupling strength when the light pulse is inside the coupled
resonator optical waveguide. The energy splitting and the coupling constant after applying electric field is calculated by
using perturbation theory for two level systems. With our approach, nonlinear materials highly susceptible to electric
fields can be engineered in low-excitation regime.
Generation of correlated photon pairs in micro/nano-fibers
Show abstract
Based on the spontaneous four wave mixing in micro/nano-fiber (MNF), we report the generation of quantum-correlated
photon pairs. The wavelengths of the signal and idler photons are in the 1310 nm and 851 nm bands, respectively. The
measured ratio between the coincidence and accidental coincidence rates of signal and idler photons is up to 530.
Moreover, we characterize the spectral property of the signal photons in the wavelength range of 1270-1610 nm. The
results reveal that the bandwidth of the photon pairs is much greater than the theoretically expected value due to the
inhomogeneity of the MNF; while the spectrum of Raman scattering in MNF is different from that in conventional
optical fibers and photonic crystal fibers, which may originate from the heating used for fabricating the MNF. Our
investigation shows that the MNF is a promising candidate for developing the sources of quantum light in micro- or
nanometer-scales, and the spectral property of photon pairs can be used to non-invasively test the diameter and
homogeneity of the MNF.
Quantum Optics IV: Applications
Nanometric surface probing through ultra-cold atoms
Show abstract
We introduce a new experimental apparatus for cold atom based on an atom chip setup. It is going to
feature for the first time the ability to interchange the atom chip frequently and rapidly. The setup will be paired with
photonic structures on-chip for the detailed study of matter-light interactions. Here, we present the design of the new
apparatus and present first ideas on how to use the unique combination of cold-atom technology with interchangeable
photonics components, both, for basic research and applications to modern information technologies.
Poster Session
Nearly deterministic loading of a single cesium atom in a magneto-optical trap and in a microscopic optical tweezer by feedback control
Show abstract
Based on feedback control techniques and our realization of nearly complete transferring cold cesium (Cs) atoms from a
magneto-optical trap (MOT) to a far-off-resonance microscopic optical tweezer, we investigated the possibility for nearly
deterministic loading of a single Cs atom in a MOT and in a microscopic optical tweezer. We combined feedback
controls on the gradient of the MOT quadrupole magnetic field (QMF) and on blue-detuned light-assisted collisions
(LAC) of confined cold atoms in the tweezer. Using active feedback on QMF of the MOT, we have achieved ~ 98% of
probability of single atom loading in a MOT. In a microscopic optical tweezer, by combining the feedback controls on
the QMF and the LAC, we finally achieved ~ 95.2% of probability of single atom loading in the tweezer. This two-path
feedback control scheme may be extended to load a small-size 2D tweezer array with exact single atom trapped in each
site simultaneously. This is very important and promising to implement an addressable multiple-qubit system for
demonstrating quantum register and quantum processor.