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- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2019 Joint Conference of the IEEE International Frequency Control Symposium anEuropean Frequency and Time Forum (EFTF/IFC) - Orlando, FL, USA (2019.4.14-2019.4.18)] 2019 Joint Conference of the IEEE International Frequency Control Symposium and European Frequency and Time Forum (EFTF/IFC) - A Versatile Testbed for CubeSat Atomic Clock Development: EOM vs Laser Current Modulation
摘要： Atomic clocks for compact satellite missions have limitations on size, weight, and power (SWaP), while requiring ever greater levels of frequency stability and accuracy. To aid in the development of next-generation low SWaP Coherent Population Trapping (CPT) clocks, we are developing a CubeSat Atomic Clock Testbed (CuSACT). This testbed will give us the capability to vary single aspects of CPT-clock design while keeping all others constant. In this presentation, we will provide an overview of CuSACT, and discuss our preliminary results comparing direct injection-current modulation of a VCSEL with electro-optic phase modulation of the VCSEL.
关键词： vapor-cell atomic clock,coherent population trapping,Rb clock,frequency modulation,electro-optic modulation,VCSEL,optical sidebands
更新于2025-09-16 10:30:52
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Near-infrared tunable diode laser absorption spectroscopy-based determination of carbon dioxide in human exhaled breath
摘要： A spectroscopic detection system for the accurate monitoring of carbon dioxide (CO2) in exhaled breath was realized by tunable diode laser absorption spectroscopy (TDLAS) in conjunction with a vertical-cavity surface-emitting laser (VCSEL) and a multipass cell with an effective optical path-length of 20 m. The VCSEL diode emitting light with an output power of 0.8 mW, covered the strong absorption line of CO2 at 6330.82 cm?1 by drive-current tuning. The minimum detectable concentration of 0.769% for CO2 detection was obtained, and a measurement precision of approximately 100 ppm was achieved with an integration time of 168 s. Real-time online measurements were carried out for the detection of CO2 expirograms from healthy subjects, different concentrations were obtained in dead space and alveolar gas. The exhaled CO2 increased significantly with the increasing physical activity, reaches its maximal value at the beginning of respiratory compensation and then decreased slightly until maximal exercise. The developed measurement system has a great potential to be applied in practice for the detection of pulmonary diseases associated with CO2 retention.
关键词： CO2,human health monitoring,Tunable diode laser absorption spectroscopy,carbon dioxide,VCSEL,exhaled breath,TDLAS,vertical-cavity surface-emitting laser
更新于2025-09-16 10:30:52
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Study on electronic blocking layer of 403 nm GaN-based vertical cavity surface emitting lasers
摘要： In order to obtain good optical characteristics in the GaN-based vertical-cavity surface-emitting laser (VCSEL), different kinds of AlGaN electron blocking layers (EBL) were introduced. These were inserted coherently near the active region to limit electron leakage into the p-doped side. The research was conducted by photonic integrated circuit simulator in three-dimensional (PICS3D). The simulated results reveal that an EBL can improve the optical characteristics of a VCSEL effectively. All the advantages are due to a reduction in the electron leakage in the quantum wells. While the voltage of the five-layer EBLs LD is lower than the voltage of the seven-layer EBLs LD, the output power of the two is approximately the same, so the five-layer EBLs is the best choice for comprehensive structure analysis as the epitaxial structure can be grown more easily on it.
关键词： PICS3D,optical characteristics,GaN-based VCSEL,electron blocking layer
更新于2025-09-12 10:27:22
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - 25 GHz Small-Signal Modulation Bandwidth with a 7-Element Electrically-Parallel Vertical-Cavity Surface-Emitting Laser Array
摘要： Small arrays of VCSELs have emerging applications in free-space optical communications for a plethora of gadgets from smartphones to appliances to sensing systems within the realm of the Internet-of-Things. For data communication we require eye-safe line-of-sight beams or cones of light radiation that can reliably and inexpensively send data (as across optical fiber) from device-to-device or serve as an illumination source or both. Via our simplified VCSEL epitaxial designs [1] we investigate various configurations of top-emitting single 980 nm VCSELs and VCSEL arrays with varying VCSEL-to-VCSEL spacing, mesa shapes, and emitting diameters. We report record combinations of small-signal modulation bandwidth (f3dB) and optical output power (L) for an electrically-parallel compact VCSEL array with 7 VCSELs in a hexagonal configuration. The VCSELs in the array are identical with oxide aperture diameters estimated to be ? ~3.5 (cid:80)m ± 0.5 (cid:80)m. We summarize key room temperature (RT) performance figures-of-merit in Fig. 1. We achieve an f3dB of 20 GHz at a bias of about I ~35 mA with an operating L exceeding 25 mW. The f3dB is as high as 24.8 GHz with L ~50 mW when I ~65 mA. The maximum wall plug efficiency (WPE) is 0.32 at I ~16 mA. We anticipate increased WPE and optical output power for a given I with heat sinking, advanced packaging, and substrate-emitting array designs. Previous best array results include an f3dB of 7.5 GHz at L = 120 mW for a 28-element 850 nm array [2] and an f3dB of 23 GHz at L = 25 mW for a single 980 nm VCSEL. In our presentation we include additional experimental results on our large ? single VCSELs and on our triple, septuple, and novemdecuple VCSEL arrays from RT to 85 °C.
关键词： optical output power,VCSEL,electrically-parallel,small-signal modulation bandwidth,hexagonal configuration
更新于2025-09-12 10:27:22
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Radiant Efficacy Enhancement for Vertical-Cavity Surface-Emitting Laser Devices Using Enhanced Specular Reflection Structures
摘要： Vertical-cavity surface-emitting laser (VCSEL) devices operate using a variety of viewing angles to satisfy the demands of different applications. One simple and universal approach to accomplish this is by using scattering elements in the packaging process for VCSEL chips. However, inevitable backward scattering loss is introduced, which suppresses the radiant efficacy of VCSEL devices. Therefore, we have proposed an enhanced specular reflection (ESR) structure with an opening circle window (OCW) to recycle the backward scattered light. The ray-tracing method is used to optimize the diameter of the OCW, as well as the thickness of the ESR structure. Furthermore, the light extraction mechanism is discussed. According to theoretical results, VCSEL devices with optimized ESR structures are fabricated and compared with traditional VCSEL devices. The experiment results demonstrate that ESR structures can significantly enhance the radiant efficacy of VCSEL devices using scattering elements. This shows great potential for applications involving illumination and 3-D imaging.
关键词： vertical-cavity surface-emitting laser (VCSEL),packaging,Enhanced specular reflection (ESR),radiant efficacy,scattering
更新于2025-09-12 10:27:22
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[IEEE 2018 Asia Communications and Photonics Conference (ACP) - Hangzhou (2018.10.26-2018.10.29)] 2018 Asia Communications and Photonics Conference (ACP) - A pair of integrated optoelectronic chips for optical interconnects
摘要： A pair of integrated optoelectronic chips based on VCSEL (Vertical-Cavity Surface-Emitting Laser) and PIN-PD is proposed for optical interconnects. The matched chips can realize bi-directional communications on a single fiber.
关键词： Optical interconnects,Optoelectronic integration,Laser,RCE-PD,VCSEL
更新于2025-09-12 10:27:22
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Monolithic integration of VCSEL and coupled cavity RCEPD for short-reach single-fiber bi-directional optical interconnects
摘要： In this paper, we propose a monolithic integration of vertical-cavity surface-emitting laser (VCSEL) and coupled cavity resonant cavity enhancement photodiode (ccRCEPD). Based on this structure, a couple of matched chips is designed for single fiber bidirectional optical interconnects. That type of integration can easily put VCSEL and (photodiode) PD into one package, which not only reduces the costs of the device packages and even cut the costs of the optical system like beam splitter, but also can save the space in optical transceiver to make it tight. These chips’ VCSELs show a threshold current of 1.6 mA and 1.7 mA, and a slope efficiency of 0.74 W/A and 0.97 W/A. VCSELs’ modulation bandwidth is 9.5 GHz and 11.0 GHz, and PDs’ response bandwidth is 10 GHz. Furthermore, the modulation bandwidth can be higher if the material of the multiple quantum wells (MQWs) is transformed GaAs/AlGaAs to InGaAs/AlGaAs. And by optimizing, the 3dB bandwidth of PD will be higher.
关键词： ccRCEPD,bidirectional optical interconnects,VCSEL,monolithic integration,quantum wells
更新于2025-09-12 10:27:22
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Inhomogeneous Current Injection and Filamentary Lasing of Semipolar (2021ˉ) Blue GaN‐Based Vertical‐Cavity Surface‐Emitting Lasers with Buried Tunnel Junctions
摘要： aperture are demonstrated under continuous wave operation with a differential efficiency of and a threshold current of 2.7 mA for a lasing mode at 452 nm. The effects of the aperture diameter on these 9λ cavity length devices is presented, showing that the differential efficiency increases with aperture size, while the threshold current density remains constant for apertures larger than 10 μm . Filamentary lasing is observed in the larger aperture sizes and it is suggested that this mode behavior is due to current injection inhomogeneity across the aperture. This theory is supported by correlation between optical nearfield images and thermal microscope images.
关键词： VCSEL,semipolar,BTJ,GaN
更新于2025-09-12 10:27:22
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[IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - Controlled Oxidation of III-V Semiconductors for Photonic Devices
摘要： The oxidation of III-V semiconductors is a crucial technological process in the mass-volume manufacturing of (singlemode) Vertical-Cavity Surface-Emitting Lasers or in the fabrication of more-recently-demonstrated integrated photonic devices. To facilitate the deployment of VCSELs in their up-rising markets but also to sustain the above-mentioned emerging uses, the shape and size of the optical/electrical apertures resulting from the selective lateral oxidation of buried layers of aluminum-containing III-V semiconductors needs to be controlled with an ever-increasing accuracy and reliability. In this paper, we will review the recent experimental investigations and model developments we have carried out to analyse and describe in detail this oxidation process. In particular, we will show that its degree of anisotropy depends on the oxidation process conditions and that the detrimental shape distortion induced by this anisotropy may be mitigated by a careful design of the etched mesas used to enable the oxidation of the buried layers.
关键词： oxidation,VCSEL,waveguides,AlOx,anisotropy
更新于2025-09-12 10:27:22
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[IEEE 2019 3rd International Conference on Circuits, System and Simulation (ICCSS) - Nanjing, China (2019.6.13-2019.6.15)] 2019 3rd International Conference on Circuits, System and Simulation (ICCSS) - Pumped Stimulated Vertical Cavity Surface Emitting Laser by Solution-processed Method
摘要： In this paper, It is fully demonstrated that the characteristics of the vertical cavity surface emitting laser (VCSEL) can be versatilely engineered by independent adjustment of the cavity and solution-processable CdSe/ZnS quantum dots (QDs), featuring low threshold (8.9 μJ/cm2), directional output (beam divergence of ≈ 10 degree), and favorable stability. Importantly, the lasing wavelength can be broadcasted to cover across the red, green, and blue region maintaining comparable thresholds, which is promising in developing single-source-pumped full-color visible lasers. The results unambiguously reveal the feasibility of CdSe/ZnS QDs as practical laser media.
关键词： laser,solution-processable,VCSEL,quantum dot
更新于2025-09-12 10:27:22