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The purpose of the conference is to highlight the recent progress in the field of vertical external cavity surface emitting lasers (VECSELs). In a VECSEL, the light is emitted perpendicular to the semiconductor gain media layers placed in an external cavity. This offers mode control enabling excellent transverse beam quality with multi-Watt output power levels. The external cavity also enables the integration of elements for nonlinear intracavity frequency conversion, wavelength tuning, or passive mode-locking.

Compared to external-cavity diode-pumped solid-state lasers, the VECSELs operate in much broader spectral regions owing to wavelengths versatility of semiconductor gain media. Direct CW emission from VECSELs has been demonstrated for the entire wavelength range covered by compound semiconductors, extending from blue to mid-IR. Moreover, efficient intra-cavity nonlinear frequency conversion allows to further broaden spectral coverage, reaching ultra-violet and terahertz emission, promoting VECSELs to a status of the most versatile laser type.

While high power, continuous-wave VECSELs have been widely used in medicine, spectroscopy, or for pumping of solid-state lasers, new applications are emerging taking advantage of the unique features they offer. For example, owing to their low-noise properties, high-power, and single-frequency wavelength-tunable operation, CW VECSELs are increasingly used in quantum-technology applications, such as ion-trapping. In parallel, mode-locked ultrafast VECSELs are opening new application opportunities in high-resolution spectroscopy, frequency metrology, and multiphoton microscopy.

A selection of invited papers will provide a comprehensive overview of the latest progress in this fast-developing field. In addition, contributed papers are solicited on all aspects of VECSEL research, including:
Best Student Presentation Award
The committee is pleased to announce that a cash prize of $500, donated by Coherent Inc., will be awarded for the best student presentation; judged, by the committee, on the basis of scientific content, impact, and clarity.

To be eligible for consideration, the student must:
  • submit their abstract online by the deadline
  • be the primary author
  • select “Yes” when asked if they are a full-time student
  • select themselves as the speaker
  • be accepted to present an oral presentation
  • make the oral presentation.
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In progress – view active session
Conference 11984

Vertical External Cavity Surface Emitting Lasers (VECSELs) XI

25 - 26 January 2022 | Room 214 (Level 2 South)
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View Session ∨
  • 1: Tutorial
  • 2: Emerging Technologies
  • 3: MECSEL I
  • 4: Mode-Locking / MECSEL II
  • 5: High Power
  • 6: Single Frequency
  • VECSELs Best Student Paper Award Ceremony
Information

Presentation times are finalized; please adhere to the schedule

Session 1: Tutorial
25 January 2022 • 10:30 AM - 11:15 AM PST | Room 214 (Level 2 South)
Session Chair: Mircea Guina, Tampere Univ. (Finland)
11984-1
Author(s): Hermann Kahle, Tampere Univ. (Finland)
25 January 2022 • 10:30 AM - 11:15 AM PST | Room 214 (Level 2 South)
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In recent years, MECSELs did undergo rapid progress. The developments in the field will be summarized and discussed, and a complete overview on the state of the art will be given. The most important progress, like the radical design simplification, double-side pumping and power scaling capabilities play a major role. Also, the main aspects of the design of active region membranes will be reviewed with respect to flexible pumping possibilities enabled by the absence of a DBR and the substrate.
Session 2: Emerging Technologies
25 January 2022 • 11:15 AM - 11:45 AM PST | Room 214 (Level 2 South)
Session Chair: Mircea Guina, Tampere Univ. (Finland)
11984-2
Author(s): Christopher A. Curwen, Jet Propulsion Lab. (United States), Univ. of California, Los Angeles (United States); Anthony D. Kim, Yu Wu, Yue Shen, Univ. of California, Los Angeles (United States); Darren J. Hayton, Jonathan H. Kawamura, Boris S. Karasik, Jet Propulsion Lab. (United States); Sadhvikas Addamane, Ctr. for Integrated Nanotechnologies, Sandia National Labs. (United States); John L. Reno, Sandia National Labs. (United States); Benjamin S. Williams, Univ. of California, Los Angeles (United States)
25 January 2022 • 11:15 AM - 11:45 AM PST | Room 214 (Level 2 South)
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We report advances in the development of THz quantum-cascade metasurface VECSELs intended for use as local oscillators in terahertz heterodyne receiver instruments for astrophysical investigation of the interstellar medium. First, by using a patch-based amplifying metasurface we obtain QC-VECSEL lasing with milliwatt output power at 4.6 THz with reduced power consumption less than 1 W. Second, we report the phase locking of a QC-VECSEL at 3.4 THz to a microwave reference using a Schottky diode mixer. Finally, we report efforts and challenges to scale down the lasing frequency of the VECSELs to 1.9 THz.
Break
Lunch/Exhibition Break 11:45 AM - 1:45 PM
Session 3: MECSEL I
25 January 2022 • 1:45 PM - 3:05 PM PST | Room 214 (Level 2 South)
Session Chair: Mircea Guina, Tampere Univ. (Finland)
11984-4
Author(s): Hoy-My Phung, Philipp Tatar-Mathes, Aaron Rogers, Patrik Rajala, Sanna Ranta, Hermann Kahle, Mircea Guina, Tampere Univ. (Finland)
25 January 2022 • 1:45 PM - 2:05 PM PST | Room 214 (Level 2 South)
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The great potential of power scaling in membrane external-cavity surface-emitting lasers (MECSELs) is rendered possible by double-side cooling as well as double-side pumping of the active region. A systematic thermal investigation is performed using the finite-element method and validated with experimental data to estimate the heat extraction capability and limits of power scaling. Various types of heat spreader materials, such as sapphire, silicon carbide, and diamond are considered. Also, the thermal behavior is compared at various pumping conditions, such as pump beam diameters and pump beam profiles.
11984-5
Author(s): Mingyang Zhang, Davide Priante, Alexander R. Albrecht, The Univ. of New Mexico (United States); Garrett D. Cole, Thorlabs Crystalline Solutions (United States); Mansoor Sheik-Bahae, The Univ. of New Mexico (United States)
25 January 2022 • 2:05 PM - 2:25 PM PST | Room 214 (Level 2 South)
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We investigate in-well pumping of a membrane external-cavity surface-emitting laser (MECSEL) for sodium guide star applications. By changing from barrier-pumping at 808 nm to in-well pumping at 1070 nm, we significantly reduced the quantum defect and – for a single pump pass – increased the slope efficiency from 21.6% to 39.5%, achieving a maximum output power of 28.5 W and a tuning range of 71 nm from 1124 nm to 1195 nm. Implementation of a multi-pass system for in-well pumping will also be discussed, including preliminary results.
11984-6
Author(s): Patrik Rajala, Philipp Tatar-Mathes, Hoy-My Phung, Jesse Koskinen, Sanna Ranta, Mircea Guina, Hermann Kahle, Tampere Univ. (Finland)
25 January 2022 • 2:25 PM - 2:45 PM PST | Room 214 (Level 2 South)
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Direct emitting broadband MECSELs, continuously tunable from 940 to 1030 nm are reported. We concentrate on designing and simulating MECSEL gain structures to improve the pump absorption and ensure broadband gain. We report on the characterization results of these laser systems showing their potential. Preliminary results indicate more than 90 nm tuning range at room temperature operation. Strategies for further improvements are discussed as well.
11984-7
Author(s): Garrett D. Cole, David Follman, Catherine Nguyen, Thorlabs Crystalline Solutions (United States); Roman Bek, Michael Zimmer, Norbert Witz, Twenty-One Semiconductors GmbH (Germany)
25 January 2022 • 2:45 PM - 3:05 PM PST | Room 214 (Level 2 South)
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Membrane-external-cavity surface-emitting lasers (MECSELs) consist of an epitaxial active region directly bonded to at least one transparent heatspreader with external cavity mirrors for feedback. This structure enables significant flexibility in the emission wavelength and yields a standalone laser gain medium amenable to enhanced power scaling via optimized thermal management. We outline a 4” wafer-scale manufacturing process for dual-SiC-heatspreader (SiC/epi/SiC) gain chips, incorporating external dielectric coatings and metallization for intimate mounting to a heatsink. Our process leverages low-temperature wafer bonding in concert with traditional deposition, lithography, and etching steps, allows hundreds of MECSEL gain chips to be simultaneously produced.
Break
Coffee Break 3:05 PM - 3:35 PM
Session 4: Mode-Locking / MECSEL II
25 January 2022 • 3:35 PM - 4:55 PM PST | Room 214 (Level 2 South)
Session Chair: Mircea Guina, Tampere Univ. (Finland)
11984-9
Author(s): Jonas Heidrich, Marco Gaulke, B. Ozgur Alaydin, Matthias Golling, Ajanta Barh, Ursula Keller, ETH Zurich (Switzerland)
25 January 2022 • 3:35 PM - 3:55 PM PST | Room 214 (Level 2 South)
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We present our first flip-chip processed, modelocked InGaSb vertical external-cavity surface-emitting laser (VECSEL) in the 2-µm wavelength range. The optically pumped VECSEL is passively modelocked with a semiconductor saturable absorber mirror (SESAM) resulting in 2.7-ps pulses with 89-mW average output power at a center wavelength of 2063 nm and a pulse repetition rate of 1.96 GHz. The standing-wave V-shaped cavity is formed by a 1% output coupler, a VECSEL gain chip as a folding cavity mirror, and a SESAM as the end mirror. An intracavity 1.5-mm silicon plate at Brewster’s angle was used for dispersion compensation and a fixed polarization.
11984-10
Author(s): Jonas Heidrich, Marco Gaulke, B. Ozgur Alaydin, Matthias Golling, Ajanta Barh, Ursula Keller, ETH Zurich (Switzerland)
25 January 2022 • 3:55 PM - 4:15 PM PST | Room 214 (Level 2 South)
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We present the characterization under intracavity conditions of semiconductor saturable absorber mirrors (SESAMs) operating from 2 – 2.4 µm. The precise nonlinear reflectivity and recovery time measurement setups reveal excellent parameters of our in-house grown 2.05 and 2.4 µm SESAMs. Low saturation fluences around 4 µJ/cm2, percent range modulation depth, extremely low non-saturable losses and fast recovery within a few tens of picoseconds have been measured for all SESAMs. Using these SESAMs output power records in modelocking of vertical external-cavity surface-emitting lasers (VECSELs), thin-disk Ho:YAG lasers at 2 µm wavelength and Cr:ZnS lasers at 2.4 µm are achieved.
11984-11
Author(s): Philipp Tatar-Mathes, Hoy-My Phung, Aaron Rogers, Patrik Rajala, Sanna Ranta, Hermann Kahle, Mircea Guina, Tampere Univ. (Finland)
25 January 2022 • 4:15 PM - 4:35 PM PST | Room 214 (Level 2 South)
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We report on the performance of MECSELs based on a non-resonant gain structure in respect with the operating lasing emission wavelength at 800 nm. Preliminary observations reveal an output power of 1.1 Watt and a 20 nm tuning range.
11984-12
Author(s): Mansoor Sheik-Bahae, The Univ. of New Mexico (United States)
25 January 2022 • 4:35 PM - 4:55 PM PST | Room 214 (Level 2 South)
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The longitudinal mode characteristics of DBR-free VECSELs -also known as membrane external cavity surface-emitting lasers (MECSELs)- with resonant-periodic gain structure gives rise to a new set of requirements for modelocking these lasers. We discuss modelocking operations in MECSELs in both standing-wave and ring cavity configurations in comparisons with the traditional VECSELs. Furthermore, we analyze the conditions for Kerr-lens modelocking (KLM) operation in MECSELs in various resonator geometries.
Session 5: High Power
26 January 2022 • 8:20 AM - 10:00 AM PST | Room 214 (Level 2 South)
Session Chair: Mircea Guina, Tampere Univ. (Finland)
11984-13
Author(s): Marco Gaulke, Jonas Heidrich, B. Ozgur Alaydin, Matthias Golling, Ajanta Barh, Ursula Keller, ETH Zurich (Switzerland)
26 January 2022 • 8:20 AM - 8:50 AM PST | Room 214 (Level 2 South)
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We report record performance and full gain characterization of an optically pumped continuous wave InGaSb VECSEL operating around 2 µm. Our flip-chip processed and backside-cooled VECSEL performs similar to intracavity heatspreader cooling and obtained even similar thermal resistance of only 3.45 KW-1 and an average output power of >800 mW. Our gain characterization setups can cover a wavelength range from 1.9 µm to 3 µm. Linear and nonlinear gain characteristics are measured as a function of wavelength, fluence, pump power and heatsink temperature. 2-µm VECSEL chips with different strategies in heat management are compared and theoretical predictions are in good agreement.
11984-14
Author(s): Nicolas Huwyler, Marco Gaulke, Jonas Heidrich, Matthias Golling, Ajanta Barh, B. Ozgur Alaydin, Ursula Keller, ETH Zurich (Switzerland)
26 January 2022 • 8:50 AM - 9:10 AM PST | Room 214 (Level 2 South)
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The key limiting factor for output power scaling of VECSELs is the thermal resistance of the structure owing to the DBR thickness and the heat conductivity of the semiconductor materials. We have successfully fabricated a flip-chip processed GaSb/AlAs0.08Sb0.92 hybrid DBR for 2 µm with only 7.5 mirror pairs and a 100-nm gold layer. The hybrid DBR reaches a high reflectivity >99.5% with a reduced total thickness of 2.3 µm. The measured spectral reflectivity of the hybrid DBR reveals a clear gold layer and matches theoretical simulations. High power 2-µm VECSEL development with the presented hybrid-mirror structure is under way.
11984-15
Author(s): Ricky D. Gibson, Air Force Research Lab. (United States); Jacob Hoehler, Air Force Research Lab. (United States), Univ. of Dayton (United States); Bradley Thompson, Air Force Research Lab. (United States), KBR, Inc. (United States); Robert G. Bedford, Air Force Research Lab. (United States)
26 January 2022 • 9:10 AM - 9:30 AM PST | Room 214 (Level 2 South)
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A single transverse mode high pulse-energy GaSb VECSEL emitting at 2040 nm was studied. The peak power exceeds 500W while maintaining good beam quality throughout the operation range. The cavity employs a Pockels cell combined with a low-loss thin film polarizer to selectively dump the intracavity energy in a 10 ns pulse. Thermal mitigation of the gain chip is achieved by both gain-switching and utilizing a long wavelength pump laser at 1470 nm compared to the traditional 980 nm pump for GaSb VECSELs. The laser has promise for incoherent LiDAR, materials processing, gas sensing, and nonlinear optics.
11984-16
Author(s): Gregory J. Fetzer, Arete Associates (United States); Juan Chilla, Coherent, Inc. (United States); Steven E. Rako, Cory Baumgarten, Nathan Woody, Arete Associates (United States); Celine D'Orgeville, The Australian National Univ. (Australia)
26 January 2022 • 9:30 AM - 10:00 AM PST | Room 214 (Level 2 South)
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Performance characteristics of a >15W single frequency VECSEL operating at 589nm will be discussed. Our work characterizes laser performance with an emphasis on suitability for guidestar laser applications. We examine, wavelength stability, linewidth, tuning and tuning agility and the ability to lock the laser to the sodium transition. In addition, we demonstrate simultaneous generation collinear beams with a frequency spacing of approximately 1.7 GHz. We will discuss plans to test the system, on-sky, in the future.
Break
Coffee Break 10:00 AM - 10:30 AM
Session 6: Single Frequency
26 January 2022 • 10:30 AM - 11:50 AM PST | Room 214 (Level 2 South)
Session Chair: Mircea Guina, Tampere Univ. (Finland)
11984-17
Author(s): Mehdi Alouini, Anwar Kerchaoui, Cyril Paranthoen, Christophe Levallois, Thomas Batté, Cyril Hamel, Steve Bouhier, Alain Le Corre, Fonctions Optiques pour les Technologies de l'information, Univ. de Rennes 1, CNRS (France); Alexandru Mereuta, Andrei Caliman, Eli Kapon, Ecole Polytechnique Fédérale de Lausanne (Switzerland)
26 January 2022 • 10:30 AM - 11:00 AM PST | Room 214 (Level 2 South)
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We report here on the first realization of an InP electrically pumped shot noise limited class A laser at 1.5µm. Its single frequency output power of 3mW offers an equivalent RIN level of -160dB/Hz for 60mA of pump current only. Class A operation ensures that the laser noise is quantum limited leading to a potentially infinite SNR as the power is increased. This realization opens the way for integration of such peculiar noiseless lasers in applications where low power consumption and footprint are mandatory. The cavity design enabling to overcome the different difficulties will be discussed.
11984-18
Author(s): Martin Lee, Paulo H. Moriya, Jennifer E. Hastie, Univ. of Strathclyde (United Kingdom)
26 January 2022 • 11:00 AM - 11:20 AM PST | Room 214 (Level 2 South)
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With their high finesse external cavities, VECSELs provide intrinsically low frequency noise, class-A operation with broad spectral coverage, making them ideal candidates for quantum technology applications, such as atomic trapping. Subsequently, the excess frequency noise observed in VECSELs originates from pump noise, environmental noise, and mechanical instabilities. For conventional diode-pumped solid-state lasers monolithic formats, such as non-planar-ring-oscillators, have provided an effective solution to reducing environmental and technical noise. Here we present a monolithic-cavity class-A VECSEL based on a 25 mm fused silica right-angle prism. We present the cavity design and initial characteristics of the device operating at frequencies required for integration with Sr atomic clocks.
11984-19
Author(s): Jussi-Pekka Penttinen, Emmi Kantola, Sanna Ranta, Arttu Hietalahti, Jarno Reuna, Roope Vuohenkunnas, Mariia Bister, Mircea Guina, Vexlum Ltd. (Finland)
26 January 2022 • 11:20 AM - 11:50 AM PST | Room 214 (Level 2 South)
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We review the progress of commercial single-frequency VECSELs for quantum technology applications. VECSELs are ideal laser sources for applications requiring low-noise watt-level single-frequency light with excellent beam quality. In particular, we present features of lasers addressing the need for spectroscopy, laser cooling and trapping for selected atoms and molecules, such as Be, Cd, Sr and Yb. Power scaling abilities in single-frequency operation are also discussed.
VECSELs Best Student Paper Award Ceremony
26 January 2022 • 11:50 AM - 12:00 PM PST | Room 214 (Level 2 South)
A cash prize will be awarded for the best student presentation; judged, by the committee on the basis of scientific content, impact, and clarity.

Award presented by Juan L. Chilla, Coherent, Inc. (United States)

Award Sponsor:
Conference Chair
Tampere Univ. (Finland)
Program Committee
Vasilis Apostolopoulos
Univ. of Southampton (United Kingdom)
Program Committee
Air Force Research Lab. (United States)
Program Committee
Coherent, Inc. (United States)
Program Committee
Univ. de Montpellier (France)
Program Committee
Jennifer E. Hastie
Univ. of Strathclyde (United Kingdom)
Program Committee
Univ. Stuttgart (Germany)
Program Committee
Elyahou Kapon
Ecole Polytechnique Fédérale de Lausanne (Switzerland)
Program Committee
ETH Zurich (Switzerland)
Program Committee
M Squared Lasers Ltd. (United Kingdom)
Program Committee
The Univ. of New Mexico (United States)
Program Committee
NAsP III/V GmbH (Germany)
Additional Information

POST-DEADLINE ABSTRACT SUBMISSIONS

  • Submissions are accepted through 06-December
  • Notification of acceptance by 20-December

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