This PDF file contains the front matter associated with SPIE Proceedings Volume 11269 including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Nanocrystalline silicon (Si) films were synthesized by nanosecond laser ablation of crystalline Si targets in low-pressure helium (He) and nitrogen (N₂) gas mixtures. Photoluminescence (PL) spectra of the prepared samples were found to depend on the He/N₂ ratio in the gas mixture. The ablation pure He atmosphere allowed us to prepare Si nanocrystals (NCs) exhibiting a PL band in red-near-IR range, while samples prepared in the presence of N₂ exhibited a strong PL band with maximum in the green-yellow region. Such a modification of PL properties can be explained by the presence of amorphous Si oxynitride (a-SiN_xO_y) on the surface of Si-NCs. Structural studies of the prepared samples by means of the scanning electron microscopy revealed different morphology for Si-NCs produced under different gas mixtures. After treating of the films by ultrasound and dispersing in water, Si-NCs can be used as novel biodegradable markers for bioimaging, while the observed spectral tailoring effect makes possible an adjustment of the PL emission of such markers to a concrete bioimaging task.

Nanotechnology promises a major improvement of efficacy of nuclear medicine by targeted delivery of radioactive agents to tumors, but this approach still needs novel efficient nanoformulations to maximize diagnostic and therapeutic functions. Here, we present a two-step method of laser ablation and fragmentation in water to produce non-radioactive 152Sm-enriched samarium oxide nanoparticles (Sm NPs), which can be converted to radioactive form of ¹⁵³Sm beta-emitters by neutron capture reaction. We found that laser ablation in deionized water leads to the formation of NPs having diverse morphology and broad size dispersion. To improve size characteristics of formed NPs, we applied additional femtosecond laser fragmentation step, which made possible a good control of mean NPs size under a drastic narrowing of size dispersion, and the spherical shape of formed NPs. Obtained colloidal solutions of Sm NPs were stable for several weeks after the synthesis. The formed NPs present a very promising object for nuclear nanomedicine.

Polypeptide gelatine has been used extensively in microbiology to enhance cellular adhesion and growth. Likewise, fabrication of biochemical sensors using a variety of organic material and nanomaterials is a growing research area particularly in experiments involving single molecular screening. Both fields of study exploit the various interactions that occur at molecular level such as charge-charge binding, hydrogen bonding and van Der Waals forces. In this work, a thin film gelatine based biosensor, containing amino acids such as glycine, proline and hydroxy-proline was synthesized on glass slides using the self-assembly method. Further -adaption involved coating gold nanoparticles onto the substrate to enhance chemical binding and improve signal intensity and sensitivity. Pharmaceutical drugs aspirin and paracetamol were used as analytes to explore the qualitative and quantitative capabilities of the sensor in molecular screening through surface enhanced Raman spectroscopy (SERS). The results showed a distinguishable qualitative difference between the Raman spectra of gelatine-drug (Gel-D) and gelatine-gold-drug (Gel-Au-D) fabricated sensors. Similarly in both Gel-D and Gel-Au-D, the peak areas of the functional groups found in both aspirin and paracetamol increased with drug concentration, yielding satisfactory calibration curves. The gelatine based biosensor thus holds potential as an in vitro sensing platform for screening of pharmaceutical drugs.

Publisher’s Note: This conference presentation, originally published on 9 March 2020, was withdrawn on 25 March 2020 per author request.

Hyper Rayleigh Scattering (HRS) is a method allowing the retrieval of metallic nanoparticles morphology. It is usually conducted in a right angle geometry preventing the full determination of all the sample information. To alleviate this problem, we report experiments in this manuscript where we have employed a multi-angle geometry in order to further complement the study. This method is applied to a standard push-pull molecular compound, a well-defined symmetry model system, and then is extended to gold metallic nanoparticles with a diameter of 5 nm. In this way, it is possible to observe how shape deformation, or in other words symmetry, is obtained as compared to the one solely retrieved from the right-angle geometry.

Nanoimprint lithography (NIL) is a technique suitable for the mass production of micro-optical elements using a mould. One drawback, however, is that the materials used in NIL have low laser-induced damage threshold (LIDT). Here, we present our results in the development of a series of high-LIDT organic-inorganic hybrid materials, and their application in NIL using moulds made by multiphoton lithography.

Arrays of hierarchical microstructures are considered nowadays as an effective method to create hydrophobic surfaces. Herein, we use femtosecond 3D printing to manufacture microstructures in different geometric patterns. Direct laser writing and, in particular, multiphoton polymerization lithography (MPL) with ultrafast laser pulses has taken additive manufacturing all the way down to the sub-micrometer scale. MPL is a 3D nanoscale manufacturing tool offering great potential for rapid prototyping and the manufacture of photonic devices, tissue scaffolds and biomechanical parts. In this study, we demonstrate the tuning of the wetting performance of surfaces via trichomes designs of 3D microstructures.

Cs-based perovskite nanocrystals (PNCs) possess alluring optoelectronic properties through compositional and structural versatility, tunable bandgap, high photoluminescence (PL) quantum yield (QY) and facile chemical synthesis. However, PL properties of solid-state samples suffer from environmental and operational degradation. Here we report alumina (AlOx) encapsulation of 0D Cs4PbBr6 nanocrystal thin films and individual nanoparticles using a modified atomic layer deposition (ALD) method with concurrent exposure of both Al and water precursors in the gas flow. We observed stronger PL intensity, increased PL lifetimes and much improved long-term stability at both film and single PNC level. These findings provide roadmap for ALD utilization to create solid-state perovskite devices.

The synthesis of nanomaterials through pulsed-laser ablation of a bulk solids can be applied for the generation of reference aerosols for applications in aerosol science, where no reliable source of reference aerosol samples currently exists. To develop aerosol generators based on laser ablation that are capable of reliable aerosol generation with well-defined properties, more data is needed on how the aerosol properties depend on the laser ablation parameters, such as wavelength, power, repetition rate, and surrounding gas. We present an aerosol generation device based on laser ablation from a nanosecond pulsed Nd:YAG laser and report initial data from our systematic study of the effect of ablation parameters on aerosol formation from different metals and graphite. The size and concentration distribution of the resulting laser-ablation-generated aerosols were measured using a scanning mobility particle sizer. The primary nanoparticles formed in the ablation chamber directly as a result of ablation were collected and imaged using scanning electron microscopy and compared to the ensuing aerosols formed after agglomeration of the nanoparticles. We found that the aerosol size and concentration increases with increasing laser irradiance and increasing repetition rate. Different gases were used for the aerosol generation, and our results shed light on how the plasma development and resulting nanoparticle formation depend on the gas environment. Certain metal aerosols formed in a synthetic air environment were larger and more concentrated than in argon and nitrogen. The charge of the aerosols was also monitored using a parallel plate capacitor.

This Conference Presentation, “Nanoscale light management with 3D scanning near-field optical microscopy for optoelectronics material design” was recorded at Photonics West LASE 2020, held in San Francisco, California, USA.

Publisher’s Note: This conference presentation, originally published on 9 March 2020, was withdrawn on 20 May 2021 per author request.

Nanomaterial synthesis and surface nanostructuring can be simultaneously realized by femtosecond laser ablation in liquids. In each field, there are some targets that are highly desired to be reached. In this paper, we will first summarize the challenging issues and targets desirable to be reached in each field and then present the results achieved in RIKEN which involves some new findings an

We have designed a microfabricated planar absolute radiometer based on a vertically aligned carbon nanotube (VACNT) absorber and an electrical power substitution method. The radiometer is designed to operate at room temperature and to be capable of measuring laser powers up to 300 mW from 300 nm to 2300 nm with an expected expanded uncertainty of 0.06% (k = 2). The electrical power substitution capability makes the radiometer absolute and traceable to the international system (SI) of units. The new bolometer is currently under construction and will replace NIST's 50 year old detector standard for free-space CW laser power measurements. We also study the possibility of reducing background temperature sensitivity by optimizing the spectral selectivity of the VACNT forest with a photonic crystal structure.

Driven by an ever-increasing demand for nanomaterials with specific functionalities, physical synthesis techniques such as Laser Ablation Synthesis in Solution (LASiS) have gained significant interest over in recent years. Commercial wet chemical synthesis methods, while having significantly higher nanomaterial yields than LASiS, typically have considerable negative environmental impact through the use of harmful reagents and solvents. LASiS therefore represents a route towards the sustainable “green” production of nanomaterials however the significant challenge to its commercialization is that of comparably low nanomaterial yields. Significant effort has been made towards increasing the production rates of LASiS, however many of the reported advances have relied on the use of high power (>20 W) or short pulse (<10 ps) laser systems which have high capital costs. Other advances have examined moving from batch production in small volumes towards the use of continuous production through the use of solvent flow systems.

Combining these advances, we have developed a new system for nanomaterial generation via LASiS incorporating a low cost, low power (< 4W) Nd:YAG laser and solvent flow system for high-efficiency nanomaterial generation. This study has shown an increase in productivity from 2.5± 0.5 mg/hr for an 11 mL batch colloid, to continuous production yields of 17± 0.7 mg/hr under flow conditions.

We present phase-responding Fourier nanotransducers based on plasmonic metamaterials for ultrasensitive control of dynamic characteristics of 2D materials and functional biosensing interfaces. These nanotransducers are designed in such a way that they can confine light in 2D plane contacting with a probed ultrathin sample, gathering information about its properties, and then transmitting the information into discrete optical beams with amplified phase relations. To demonstrate their potential of Fourier transducers in biosensing, we designed Fourier nanotransducers based on periodic gold nanostructures and applied it in a newly developed protocol for the detection of important antibiotic chloramphenicol (CAP). Such biosensing tests showed the lower detection limit at fg mL⁻¹ level, which several orders of magnitude better than reported in the literature. The implementation of Fourier nanotransducers opens new opportunities for a radical improvement of current state-of-the art plasmonic biosensing technology.

The present study is focused on the development of advanced technology for creation of plasmonic composite nanostructures for Surface Enhanced Raman Spectroscopy (SERS) detection of ammonium nitrate. The investigation of the interaction of nanostructured composite objects with electromagnetic field, the description of their optical properties as well as determination of mechanisms and conditions for their effective modification brings the information for potential application as SERS substrates. The ZnO thin films are deposited by pulsed lased deposition (PLD) in an oxygen environment at high substrate temperature. The laser grown ZnO films are modified by Ag-ion implantation. The produced nanocomposites are subsequently laser annealed at different laser wavelengths. The influence of the ion implantation doses and the laser annealing parameters on the SERS activity of produced nanostructures is investigated. The observation of morphology of the samples demonstrates the influence of the laser annealing wavelength on the size distribution of embedded silver nanoparticles on the ZnO matrix. The plasmonic behaviour of embedded metal nanoparticles is determined by studying the optical properties of the fabricated structures. The proposed combined method for synthesis has potential application in fabrication of reliable substrates for Raman spectroscopy analysis with high sensitivity. The design of appropriate structures by laser and ion implantation methods can increase the efficiency of the high resolution analyses.

Widely tunable continuous wave optical parametric oscillators (cw OPOs) are gaining popularity as novel sources of tunable laser light, not least due to the unprecedented wavelength coverage in the visible and the near infrared spectral range. While the potential and the advantages of tunable cw OPOs are becoming increasingly recognized, in particular within the quantum research community, the experimental requirements are often challenging. In this context, we discuss the characteristics of state-of-the-art tunable cw OPO designs and describe several tuning schemes tailored to meet various experimental needs. In an illustrative fashion, we compare several recently published experimental datasets from photoluminescence excitation experiments, which have been carried out on ensembles as well as on individual quantum emitters under different experimental conditions.