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Power and Efficiency Scaling of GaAs-Based Edge-Emitting High-Power Diode Lasers

IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS 2025年第2期31卷

作者： Crump, Paul Boni, Anisuzzaman Elattar, Mohamed Khamari, S. K. Marko, Igor P. Sweeney, Stephen J. Arslan, Seval King, Ben Miah, Md. Jarez Martin, Dominik Knigge, Andrea Casa, Pietro Della Traenkle, Guenther Ferdinand Braun Inst FBH D-12489 Berlin Germany Univ Glasgow Glasgow City G12 8QQ Scotland FBH Berlin D-12489 Berlin Germany RRCAT Indore 452013 India Univ Glasgow Glasgow City G12 8LT Scotland

current progress in the scaling of continuous wave optical output power and conversion efficiency of broad-area GaAs-based edge emitters, broad-area lasers (BALs), operating in the 900 & mldr;1000 nm wavelength range is presented. Device research and engineering efforts have ensured that BALs remain the most efficient of all light sources, so that in the past 10 years, power conversion efficiency at 20 W continuous wave (CW) output power from BA lasers with a 90 & mldr;100 mu m wide stripe has increased 1.5-fold to 57% (via epitaxial layer design developments), whilst peak CW power per single emitter has increased around 3-fold to 70 W (via scaling of device size), with further scaling underway, for example via use of multi-junction designs. However, the peak achievable CW power conversion efficiency and CW specific output power (defined here as peak output power from a 100 mu m stripe diode lasers with a single p-n junction) has changed remarkably little, remaining around 70% and 25 W, respectively, for the past decade. Fortunately, research to understand the limits to peak efficiency and specific output power has also shown progress. Specifically, recent studies indicate that spatial non-uniformity in optical field and temperature play a major role in limiting both power and conversion efficiency. Technological efforts motivated by these discoveries to flatten lateral and longitudinal temperature profiles have successfully increased both power and efficiency. In addition, epitaxial layer designs with very high modal gain successfully reduce threshold current and increase slope at 25 degrees C to values comparable to those observed at 200 K, offering a path toward the 80% conversion efficiency range currently seen only at these cryogenic temperatures. Overall, whilst operating efficiency and power continue to scale rapidly, a technological path for increased specific power and peak efficiency is also emerging.

关键词： optical resonators Semiconductor lasers Power generation Diode lasers Power lasers optical reflection Epitaxial layers Stimulated emission Reflectivity Power conversion Quantum well lasers power conversion

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Halogen source illumination optimization using a beam shaping biconic lens array 14

Halogen source illumination optimization using a beam shapin...

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current developments in Lens design and optical engineering XXIV 2023

作者： Smeesters, Lien Rosseel, Dries Vervaeke, Michael Thienpont, Hugo Department of Applied Physics and Photonics Pleinlaan 2 Brussels1050 Belgium

ISBN: (纸本)9781510665460

Illumination optical design using non-coherent sources is of major interest for sensing applications requiring a uniform illumination. We present the development of a custom biconic lens array, enabling beam shaping of a halogen source array to a rectangular uniform illumination. First, the tungsten halogen sources were accurately modelled considering the near-field emission pattern and broadband spectrum. Following, the illumination lens array is optimized, including a study on the optimal arrangement and pitch of the array, and ensuring a manufacturable design by taking the optical and mechanical tolerances into account. The optimized lens array comprises of custom lenses (Ø 20 mm) featuring a first spherical surface and a second biconic surface with different radii of curvature and aspherical coefficients (up to the 8th order) in the X and Y direction. A spatial uniformity, defined as the standard deviation of the flux distribution, of 0.0002 was achieved within the envisioned illumination area of 50 x 20 mm2 being close to a perfect uniformity considering a targeted value of 0. Finally, the aspheric biconic lens is manufactured using ultraprecision diamond tooling (Nanotech 350FG), and its performance is successfully validated in a laboratory demonstrator setup, giving rise to an optimized and uniform halogen source illumination. © 2023 SPIE.

关键词： optical design

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design and modeling of high‑performance mid‑wave infrared InAsSb‑based nBn photodetector using barrier band engineering approaches

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Frontiers of Optoelectronics 2023年第1期16卷 73-83页

作者： Maryam Shaveisi Peiman Aliparast Aerospace Research Institute(Ministry of Science Research and Technology)Tehran ***Iran

We report a new nBn photodetector(nBn-PD)design based on the InAlSb/AlSb/InAlSb/InAsSb material systems for midwavelength infrared(MWIR)*** this structure,delta-doped compositionally graded barrier(δ-DCGB)layers are suggested,the advantage of which is creation of a near zero valence band ofset in nBn *** design of theδ-DCGB nBn-PD device includes a 3µm absorber layer(n-InAs0.81Sb0.19),a unipolar barrier layer(AlSb),and 0.2μm contact layer(n-InAs0.81Sb0.19)as well as a 0.116µm linear grading region(InAlSb)from the contact to the barrier layer and also from the barrier to the absorber *** analysis includes various dark current contributions,such as the Shockley-Read-Hall(SRH),trap-assisted tunneling(TAT),Auger,and Radiative recombination mechanisms,to acquire more precise ***,we show that the method used in the nBn device design leads to difusion-limited dark current so that the dark current density is 2.596×10^(−8)A/cm^(2)at 150 K and a bias voltage of−0.2 *** proposed nBn detector exhibits a 50%cutof wavelength of more than 5µm,the peak current responsivity is 1.6 A/W at a wavelength of 4.5µm and a−0.2 V bias with 0.05 W/cm2 backside illumination without anti-refective *** maximum quantum efciency at 4.5µm is about 48.6%,and peak specifc detectivity(D*)is of 3.37×10^(10)cm⋅Hz1/2/***,to solve the refection concern in this nBn devices,we use a BaF_(2)anti-refection coating layer due to its high transmittance in the MWIR *** leads to an increase of almost 100%in the optical response metrics,such as the current responsivity,quantum efciency,and detectivity,compared to the optical response without an anti-refection coating layer.

关键词： Mid-wave infrared detectors iii-V compound semiconductors Grading material systems nBn architecture

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Dioptric Plan Multi Apochromat objectives for microscopes. optical design 14

Dioptric Plan Multi Apochromat objectives for microscopes. O...

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current developments in Lens design and optical engineering XXIV 2023

作者： Frolov, Dmitry N. Vinogradova, Olga A. Frolov, Alexey D. Pavlii, Aleksandr D. Project Labor-microscopes St.-Petersburg Russia LLC "Optotekhnika" St.-Petersburg Russia

ISBN: (纸本)9781510665460

For some types of studies on a microscope, optics is required, which has a multi apochromatic aberration correction in a continuous spectral range from the nearest short -wave UV to the nearest IR spectral areas. In the NUV range, in some cases, it is required to ensure the focus of laser sources radiation on the wavelengths of 248, 222, 213 and even 193 Nm. The work is also required for the near IR region, for example, for focusing laser sources radiation on wavelengths 1315, 1523 and even 2010 and 2080 nm. A priori such optics should also work in a visible spectral range. All studies can be carried out within the indicated a continuous NUV - NIR of the range. We propose to investigate the fundamental possibility of creating lens objectives for which chromatic aberrations are corrected in a wide spectral range. In addition, optics are required for research in the SWIR, MWIR, and LWIR spectral ranges. © 2023 SPIE.

关键词： Microscopes

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Cyanidometallates and Polyresorcinols: Wealth of Molecular Synthons, Structural Hierarchy, and optical Properties

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CRYSTAL GROWTH & design 2024年第21期24卷 8782-8793页

作者： Jedrzejowska, Katarzyna Kobylarczyk, Jedrzej Muziol, Tadeusz M. Dziedzic-Kocurek, Katarzyna Stefanczyk, Olaf Ohkoshi, Shin-ichi Podgajny, Robert Jagiellonian Univ Krakow Fac Chem PL-30387 Krakow Poland Jagiellonian Univ Krakow Doctoral Sch Exact & Nat Sci Krakow PL-30348 Poland Inst Nucl Phys PAN PL-31342 Krakow Poland Nicolaus Copernicus Univ Torun Fac Chem PL-87100 Torun Poland Jagiellonian Univ Marian Smoluchowski Inst Phys PL-30348 Krakow Poland Univ Tokyo Sch Sci Dept Chem Tokyo 1130033 Japan

Crystal engineering focuses on the design of functional materials through the recognition and description of specific supramolecular synthons. In this study, we developed a series of centrosymmetric cocrystal salt solvates (PPh4)(3)[M(CN)(6)](L)(n)msolv [M = Cr(iii), Fe(iii), Co(iii);L = polyresorcinol coformers acting as multiple hydrogen bond donors: 3,3 ',5,5 '-tetrahydroxy-1,1 '-biphenyl (DiR, n = 1) or tetrakis(3 ',5 '-dihydroxy-[1,1 '-biphenyl]-4-yl)methane (TetraRB, n = 1.5)] denoted as MDiR ' and MTetraRB, respectively. Both architectures feature supramolecular trans-bis(chelated) {[M(CN)(6)](3-);(H(2)DiR)(2)(Hsolv)(2)} or {[M(CN)(6)](3-);(H(2)TetraRB)(2)(HTetraRB)(2)} motifs within their hydrogen-bonded subnetworks, alternative and complementary to the relevant cis-bis(chelated) motifs observed by us previously. MDiR ' phases appear due to the instability of previously reported noncentrosymmetric MDiR phases in crystallization mixtures, both architectures related as structural supramolecular isomers. MTetraRB crystals demonstrate the coexistence of the above-mentioned hydrogen-bonded synthons and linear arrangement of TetraRB coformers, controlled by their size, mutual interlocking, and peripheral O-TetraRB-HO-TetraRB hydrogen bonds. The photoluminescent response is correlated with the dimensionality of hydrogen bonds and the extent of the pi orbital system of L. A complete landscape of hydrogen-bonded synthon geometry, symmetry of crystal lattice, crystal stability, and optical properties involving the previous and current congeners to the series is provided to contribute to the roadmap of rational design and construction of functional materials.

关键词： Crystal symmetry

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design of ophthalmic contact lens using Q-type aspheres with reduced error budget for high visual acuity 25

Design of ophthalmic contact lens using Q-type aspheres with...

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Conference on current developments in Lens design and optical engineering XXV

作者： Peng, Wei-Jei Lee, Tsung-Xian Natl Taiwan Univ Sci & Technol Grad Inst Appl Sci & Technol 43Sec 4Keelung Rd Taipei 106 Taiwan Natl Taiwan Univ Sci & Technol Grad Inst Color & Illuminat Technol 43Sec 4Keelung Rd Taipei 106 Taiwan

ISBN: (纸本)9781510679221;9781510679238

This paper investigates the design of an ophthalmic rigid contact lens (CL) that has a Q-type aspheric surface to reduce the tolerance error budget and produce higher visual acuity. CLs for myopia correction are typically made with spherical surfaces;when such CLs are worn in darkness, the visual acuity degrades severely due to the spherical aberration generated by pupil dilation. To maximize visual acuity, an aspheric CL is essential because it can correct the spherical aberration. In this study, a CL is designed based on a schematic eye model for evaluating the modulation transfer function (MTF) on the retina, and the result shows that the visual acuity produced by an aspheric CL is superior to that produced by a spherical CL. The traditional power-series polynomial is commonly used for aspheric surface design, but the aspheric slope cannot be controlled during optimization. The large slope departure from a best-fit sphere leads to high tolerance sensitivity and an inflection point;however, the CL does not permit such results. To solve this problem, the Q-type polynomial with slope constraint proposed by Forbes is applied to the aspheric CL in this study. The Q-type aspheric polynomial can not only enhance the optimization efficiency due to its orthogonal characteristics, but also reduce error budget for maximal manufacturing yield. The simulation results demonstrated that the spherical aberration is successfully reduced by the Q-type aspheric CL for better visual acuity in darkness.

关键词： Rigid contact lens Q-type asphere power-series asphere myopia correction spherical aberration schematic eye model

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Subcell-Resolved EQE Method Using Reverse Voltage Biasing for Multijunction Photovoltaics With Overlapping Subcell Absorptance

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PROGRESS IN PHOTOVOLTAICS 2025年

作者： Beattie, Meghan N. Schachtner, Michael Siefer, Gerald Lackner, David Hoehn, Oliver Hinzer, Karin Helmers, Henning Fraunhofer Inst Solar Energy Syst ISE Freiburg Germany Univ Ottawa Sch Elect Engn & Comp Sci SUNLAB Ottawa ON Canada

External quantum efficiency (EQE) measurements of individual subcells in multijunction photovoltaic devices are essential to evaluate current matching and to iterate the design process. The standard light biasing technique used to measure subcell EQE falls short when multiple subcells absorb within the same spectral region. In this work, we demonstrate a three-step reverse voltage biasing EQE method, which measures any number of subcells with overlapping absorptance: (1) A light bias is applied to generate current mismatch between the subcells. (2) current-voltage (I-V) characteristics are measured into reverse bias, where the limiting subcell enters reverse-bias breakdown and the device current climbs to a plateau at the photocurrent of the next limiting subcell, producing a staircase I-V curve. (3) Each subcell EQE curve is measured using a voltage bias within its current plateau. We demonstrate this approach for a two-junction GaAs-based photonic power converter, comparing to the standard light biasing method and revealing better than 0.8% absolute agreement when the top junction is preferentially biased in the reverse voltage biasing method. We demonstrate the viability of the method by measuring the EQE of all subcells in a six-junction GaAs-based photonic power converter.

关键词： external quantum efficiency iii-V semiconductors laser power converter luminescence coupling multijunction optical power transmission photonic power converter power by light spectral responsivity

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Wide field of regard metalens receiver for free space optical communication 14

Wide field of regard metalens receiver for free space optica...

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current developments in Lens design and optical engineering XXIV 2023

作者： Islam, Md Shafiqul Boyraz, Ozdal University of California Irvine IrvineCA92697 United States

ISBN: (纸本)9781510665460

In conventional free space optical communication receivers, focusing optics reduces the field of regard (in the range of millidegree) while increasing the power received by the detector. As a result, a receiver communicates with one transmitter at a time. In this paper, we propose a novel two-metalens-receiver system that offers a wider field of regard (in the range of degrees) to capture the optical signal from a large Angle of Arrival (AoA). The first metalens of the system compresses and separates optical beams, based on different incident angles. The compression factor of the first metalens needs to be chosen based on the receiver system’s overall length, aperture size, and minimum angular separation between the transmitters. The second metalens redirects and focuses the beam to the detector sitting on the optical axis. Physical Optics calculation with the proposed phase profile as a phase mask shows that our proposed system increases the power received by the detector up to 1000 times compared to the conventional system for large AoA. As a result, transmitters with wide angular (and spatial) separation can communicate with the proposed receiver simultaneously. The designed phase profile is implemented by a meta-unit cell with varying diameters of Si nanopillars sitting on the quartz substrate. Finally, Quasi-3D full wave simulation is carried out to show the effectiveness of the two metalens-receiver systems. © 2023 SPIE.

关键词： Physical optics

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Hybrid refractive-metalens design for imaging applications 14

Hybrid refractive-metalens design for imaging applications

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current developments in Lens design and optical engineering XXIV 2023

作者： Ding, Yijun Stone, Bryan D. Bahl, Mayank Heller, Evan Scarmozzino, Robert Synopsys Inc. 199 S. Los Robles Ave. Suite 400 PasadenaCA91101 United States

ISBN: (纸本)9781510665460

Metalenses can be used as standalone single elements or incorporated as one component of a subassembly that also includes other non-metalens optical elements. Because of the sub-wavelength length scale of the meta-atoms, ray-based methods for analysis and optimization may not be considered appropriate. However, by treating the imparted phase appropriately, ray-based methods can be used to design and analyze optical systems that incorporate one or more metalenses. These methods can be applied to imaging systems or illumination systems composed solely of metalenses, or systems that incorporate a mix of metalenses and conventional refractive, reflective, or diffractive optical elements. There are two pieces of information that are required by the ray trace: i) the ray directions following the metalens, and ii) the amount of energy that the ray carries. The distribution of the meta-atoms in the metalens can be used to determine ray directions and Fourier analysis allows for estimation of the energy carried by the rays. The method relies on having access to the imparted phase (from an EM solver, say) that can be accessed during the ray trace. This approach allows for workflows that are familiar to lens designers—even those without experience designing metalenses—while offering results that are in excellent agreement with more rigorous wave-based analyses. This approach is applicable to both polarization-insensitive and polarization-sensitive designs. In this paper, we discuss the design approach and offer design examples. © 2023 SPIE.

关键词： Polarization

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Recent developments in the state-of-the-art optoelectronic synaptic devices based on 2D materials: a review

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JOURNAL OF MATERIALS CHEMISTRY C 2024年第15期12卷 5299-5338页

作者： Jana, Rajesh Ghosh, Sagnik Bhunia, Ritamay Chowdhury, Avijit SN Bose Natl Ctr Basic Sci Dept Condensed Matter & Mat Phys Kolkata 700106 India Uppsala Univ Dept Mat Sci & Engn Div Solid State Phys S-75237 Uppsala Sweden

The synaptic plasticity observed in biological synapses encompasses various timescales crucial for memory, learning, and diverse signal processing with minimal power consumption. Likewise, the synaptic devices, a cutting-edge paradigm in neuromorphic engineering, use external stimuli to replicate biological synaptic functions with utmost energy efficiency, circumventing the constraints imposed by the von Neumann bottleneck. Due to their inherent characteristics like near-atomic thickness, tunable bandgap, defect-mediated states, robust electrical-optical response, high compatibility, and scalability, 2D materials hold significant potential as building blocks for optoelectronic artificial neuromorphic devices. In particular, the distinctive traits of 2D materials facilitate notable improvements in synaptic performances, including learning capability and power efficiency, depending on the materials, device architectures, and external stimuli. This review focuses on state-of-the-art developments in device structures, working principles, design strategies of materials, and the integration of 2D material-based optoelectronic synaptic devices. Herein, different biological synaptic functions with timescales are introduced first, followed by the working mechanism of optoelectronic synaptic devices based on 2D materials. Furthermore, the syntheses and exfoliation of 2D materials, including their heterostructures (2D-0D, 2D-1D, and 2D-2D) and different device configurations (2 or 3 terminal integrated devices), are outlined for synaptic applications. The specific applications of 2D material-based optoelectronic synapses in Boolean functions, visual image memorization, and image processing are emphasized, with subsequent discussions addressing the current challenges and future perspectives in this field. This review showcases the diverse functionalities of 2D materials and state-of-the-art developments in device structures, working principles, design strategies of materials, a

关键词： Energy efficiency

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