- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Complete Scene Reconstruction by Merging Images and Laser Scans
摘要： Optical fibre transmission has enabled greatly increased transmission rates with 10 Gb/s common in local area networks. End users find wireless access highly convenient for mobile communication. However, limited spectrum availability at microwave frequencies results in per-user transmission rates limited to much lower values, e.g., 500 Mb/s for 5-GHz band IEEE 802.11ac. Extending the high data-rate capacity of optical fiber transmission to wireless devices requires greatly increased carrier frequencies. This paper will describe how photonic techniques can enable ultrahigh capacity wireless data distribution and transmission using signals at millimeter-wave and TeraHertz (THz) frequencies.
关键词： photonic integrated circuits,microwave photonics,Broadband communication,optical mixing,optical heterodyne,millimeter (mm)-wave generation,optical phase lock loops,semiconductor lasers
更新于2025-09-19 17:13:59
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Membrane III-V/Si DFB Laser using Uniform Grating and Width-Modulated Si Waveguide
摘要： Membrane buried-heterostructure III-V/Si distributed feedback (DFB) lasers with a stopband-modulated cavity on a Si substrate have been developed. The membrane III-V layers with 230-nm thick enable us to construct an optical supermode with a 220-nm-thick Si waveguide that is used in standard Si photonics platform. We employ a uniform grating and Si waveguide, in which Si waveguide width is modulated to control the center wavelength of the stopband. The cavity can be designed by controlling the modulation width and modulation length of Si waveguide. Therefore, it is easy to engineer and fabricate the laser cavity compared with the cavity using λ/4-phase shift grating. Output light from the cavity is coupled to Si waveguide through InP inverse taper waveguide, and then coupled to SiOx waveguide through Si inverse taper waveguide, which provides the 2-dB fiber coupling loss. We have demonstrated single-mode lasing by using Si waveguide, where its width is increased 80 nm at the center of the cavity. The threshold current and maximum fiber output power are 3 mA and 4 mW, respectively. By extending the active region length to 1 mm, 17-mW fiber coupled output power is obtained. High-temperature operation up to 130°C is also obtained with a 1-mW fiber output power.
关键词： photonic integrated circuits,semiconductor lasers,Silicon photonics
更新于2025-09-19 17:13:59
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Metalorganic Vapor Phase Epitaxy (MOVPE) (Growth, Materials Properties, and Applications) || Quantum Dots
摘要： This chapter focuses only on quantum dots (QDs) embedded inside a semiconductor structure, like quantum wells (QWs) or partly quantum wires (QWrs). Freestanding QDs with a much larger application field, which can be prepared from the same material, are not covered in this chapter. The reason for this is that we will write about MOVPE QD preparation only (not, for example, about colloidal, metal, or other freestanding QDs). A research report about the market for the whole family of QDs can be found in [1]. QDs are small pieces of semiconductor nanocrystals (mainly) with sizes in the range from a few to tens of nanometers. The first idea of QDs having properties different from those of the bulk material was published by Ekimov and Onushchenko in 1981 [2]. Their QDs were prepared in colloidal solution, not yet QDs embedded in the heterostructure: “The exciton absorption spectrum of microscopic CuCl crystals grown in a transparent dielectric matrix has been studied. The size of the microscopic crystals was varied in a controlled manner from several tens of angstroms to hundreds of angstroms. There is a short‐wave shift (of up to 0.1 eV) of the exciton absorption lines, caused by a quantum size effect” [2]. During the early 1990s, embedded QDs were prepared by molecular beam epitaxy (MBE) [3–7] in several laboratories, as described in [8]. MOVPE‐grown QDs were reported in 1991 [9, 10], but with little response (12 and 0 citations, respectively). MBE seems to be more suitable for attaining an exact layer thickness down to fractions of a monolayer. QD MOVPE papers published later [11–14] attracted much more interest. An attempt to realize industrial MOVPE‐prepared QD‐based semiconductor lasers for fiber optic telecommunications appeared during the first years of this century (EU project DOTCOM 2002–05), but without a real impact on industrial production.
关键词： quantum dots,semiconductor lasers,optical properties,growth procedures,MOVPE
更新于2025-09-19 17:13:59
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Perspective: optically-pumped III–V quantum dot microcavity lasers via CMOS compatible patterned Si (001) substrates
摘要： Direct epitaxial growth III–V quantum dot (QD) structures on CMOS-compatible silicon substrates is considered as one of the most promising approaches to achieve low-cost and high-yield Si-based lasers for silicon photonic integration. However, epitaxial growth of III–V materials on Si encounters the following three major challenges: high density of threading dislocations, antiphase boundaries and thermal cracks, which significantly degrade the crystal quality and potential device performance. In this review, we will focus on some recent results related to InAs/GaAs quantum dot lasers on Si (001) substrates by III–V/IV hybrid epitaxial growth via (111)-faceted Si hollow structures. Moreover, by using the step-graded epitaxial growth process the emission wavelength of InAs QDs can be extended from O-band to C/L-band. High-performance InAs/GaAs QD micro-disk lasers with sub-milliwatts threshold on Si (001) substrates are fabricated and characterized. The above results pave a promising path towards the on-chip lasers for optical interconnect applications.
关键词： quantum dots,silicon photonics,epitaxial growth,semiconductor lasers
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE Conference on Power Electronics and Renewable Energy (CPERE) - Aswan City, Egypt (2019.10.23-2019.10.25)] 2019 IEEE Conference on Power Electronics and Renewable Energy (CPERE) - Analysis, Design and Simulation of a DC Photovoltaic Microgrid with Electric Vehicle Charging Capability
摘要： Optical fibre transmission has enabled greatly increased transmission rates with 10 Gb/s common in local area networks. End users find wireless access highly convenient for mobile communication. However, limited spectrum availability at microwave frequencies results in per-user transmission rates limited to much lower values, e.g., 500 Mb/s for 5-GHz band IEEE 802.11ac. Extending the high data-rate capacity of optical fiber transmission to wireless devices requires greatly increased carrier frequencies. This paper will describe how photonic techniques can enable ultrahigh capacity wireless data distribution and transmission using signals at millimeter-wave and TeraHertz (THz) frequencies.
关键词： optical heterodyne,optical mixing,optical phase lock loops,millimeter (mm)-wave generation,microwave photonics,photonic integrated circuits,Broadband communication,semiconductor lasers
更新于2025-09-19 17:13:59
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High wall-plug efficiency 808-nm laser diodes with a power up to 30.1 W
摘要： A very highly efficient InGaAlAs/AlGaAs quantum-well structure was designed for 808 nm emission, and laser diode chips 390-μm-wide aperture and 2-mm-long cavity length were fabricated. Special pretreatment and passivation for the chip facets were performed to achieve improved reliability performance. The laser chips were p-side-down mounted on the AlN submount, and then tested at continuous wave (CW) operation with the heat-sink temperature setting to 25 °C using a thermoelectric cooler (TEC). As high as 60.5% of the wall-plug efficiency (WPE) was achieved at the injection current of 11 A. The maximum output power of 30.1 W was obtained at 29.5 A when the TEC temperature was set to 12 °C. Accelerated life-time test showed that the laser diodes had lifetimes of over 62 111 h operating at rated power of 10 W.
关键词： high power semiconductor lasers,COMD,high wall-plug efficiency
更新于2025-09-19 17:13:59
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Parallel information processing using a reservoir computing system based on mutually coupled semiconductor lasers
摘要： Via the nonlinear channel equalization and the Santa-Fe time series prediction, the parallel processing capability of a reservoir computing (RC) system based on two mutually coupled semiconductor lasers is demonstrated numerically. The results show that, for parallel processing the prediction tasks of two Santa-Fe time series with rates of 0.25 GSa/s, the minimum prediction errors are 3.8 × 10?5 and 4.4 × 10?5, respectively. For parallel processing two nonlinear channel equalization tasks, the minimum symbol error rates (SERs) are 3.3 × 10?4 for both tasks. For parallel processing a nonlinear channel equalization and a Santa-Fe time series prediction, the minimum SER is 6.7 × 10?4 for nonlinear channel equalization, and the minimum prediction error is 4.6 × 10?5 for Santa-Fe time series prediction.
关键词： Santa-Fe time series prediction,parallel processing,reservoir computing,nonlinear channel equalization,semiconductor lasers
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE High Power Diode Lasers and Systems Conference (HPD) - Coventry, United Kingdom (2019.10.9-2019.10.10)] 2019 IEEE High Power Diode Lasers and Systems Conference (HPD) - Simulation of the slow-axis beam properties of broad-area lasers and its use in the development of high-brightness sources
摘要： The objective of this work is to demonstrate that the slow-axis beam properties of broad-area diode lasers can be predicted by numerical modeling and that the results guide design decisions in the semiconductor laser development. We present a numerical study for 6 different semiconductor laser single emitter designs and compare the computed results to experimental values. The devices differ in width of the contact opening, cavity length, position and depth of an index trench, and facet re?ectivity.
关键词： Semiconductor Lasers,Index-Guided,Beam Propagation Method,Lasers,Modeling,Gain-Guided,Frequency Domain,Simulation,Thermal Lens,Diode Lasers,Broad-Area
更新于2025-09-16 10:30:52
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Electrically Pumped Microring Parity-Time- Symmetric Lasers
摘要： Microscale and nanoscale electrically pumped lasers are expected to play an indispensable role in future photonic integrated circuits. Small footprint, low threshold, high efficiency, and large side-mode suppression ratio (SMSR) are among the most important characteristics that such on-chip emitters should exhibit—allowing for large-scale integrability, low energy consumption, and stable output power. Microring resonators are one of the main contenders for the realization of such compact light sources. However, the use of microring laser cavities has been so far hindered by their tendency to operate in multiple modes. Quite recently, several studies have shown that notions from parity-time (PT)-symmetry and non-Hermitian physics can be utilized to effectively enforce single-mode operation in semiconductor microring laser arrangements. However, as of now, most works in this area were mainly devoted to the proof of concept demonstrations, while the feasibility of practical implementation has remained largely unexplored. In this article, we demonstrate the first regrowth free, electrically pumped microscale PT-symmetric laser. Our results can pave the way toward the utilization of exceptional points in more diverse applications ranging from on-chip light sources and modulators to laser beam steering systems and active sensors.
关键词： semiconductor lasers,ring lasers,Optical waveguides
更新于2025-09-16 10:30:52
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[IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Graphene-like Si <sub/>3</sub> N <sub/>3</sub> and Si <sub/>3</sub> N <sub/>4</sub> Nanolayers on Silicon Surface
摘要： In this paper, we present a 1050-nm electrically pumped microelectromechanically tunable vertical cavity surface-emitting laser (MEMS-VCSEL) with a record dynamic tuning bandwidth of 63.8 nm, suitable for swept-source optical coherence tomography (SS-OCT) imaging. These devices provide reduced cost and complexity relative to previously demonstrated optically pumped devices by obviating the need for a pump laser and associated hardware. We demonstrate ophthalmic SS-OCT imaging with the electrically-pumped MEMS-VCSEL at a 400 kHz axial scan rate for wide-field imaging of the in vivo human retina over a 12 mm × 12 mm field and for OCT angiography of the macula over 6 mm × 6 mm and 3 mm × 3 mm fields to show retinal vasculature and capillary structure near the fovea. These results demonstrate the feasibility of electrically pumped MEMS-VCSELs in ophthalmic instrumentation, the largest clinical application of OCT. In addition, we estimate that the 3 dB coherence length in air is 225 ± 51 m, far greater than required for ophthalmic SS-OCT and suggestive of other distance ranging applications.
关键词： Medical imaging,tunable lasers,optical coherence tomography,micro and nano opto-electromechanical systems (MOEMS),semiconductor lasers
更新于2025-09-16 10:30:52