- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Photodetectors [Working Title] || Avalanche Photodiode Focal Plane Arrays and Their Application to Laser Detection and Ranging
摘要： Focal-plane avalanche photodiodes (APDs) are being more and more widely and deeply studied to satisfy the requirement in weak light and single photon imaging. The progresses of this worldwide study, especially the distinctive researches and achievements in Southwest Institute of Technical Physics and University of Electronic Science and Technology of China are reviewed in this chapter. We successfully fabricated up to 64 × 1 linear-mode Si APD arrays, and 32 × 32–64 × 64 Si single-photon avalanche detector (SPAD) arrays, and applied them in Laser Detection and Ranging (LADAR) platforms like driverless vehicles. Also, we developed 32 × 32–64 × 64 InGaAsP/InP SPAD arrays, and constructed three-dimensional imaging LADAR using them. Together with the progresses of other groups and other materials, we see a prospective future for the development and application of focal-plane APDs.
关键词： avalanche photodiode,focus plane,laser detection and ranging
更新于2025-09-16 10:30:52
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Optical Fiber Communications (Principles and Applications) || Optical Receivers
摘要： The purpose of a receiver in an electronic communication system is to extract the information sent by the corresponding transmitter with as minimum a carrier power level as possible. The primary function of an optical receiver in an optical fiber communication link is to convert the received optical signal into an equivalent electrical signal and recover the data. One of the main components of an optical receiver is a photodetector that converts incident optical signals into electric signals using photoelectric effects. High Sensitivity, dynamic range, fast response (i.e., acquisition time), high reliability, low noise, compatible size with that of fiber, and low cost are some of the important requirements of a photodetector. These requirements are best met by semiconductor photodetectors that convert an optical signal transmitted via optical fiber cables to equivalent electrical signals for further processing to achieve the desired output. The type of photodetectors suitable for three optical spectrum ranges of 800–900 nm, 900–1100 nm, and 1100–1600 nm vary in the material used for their fabrication as well as assembly techniques. A p–i–n photodiode is an ideal semiconductor photodetector device, because it can provide high quantum efficiency, fast response and capability to operate at higher modulation frequencies. The minimum received optical power that can be detected by a photodetector is limited by noise. A fully integrated single beam optical receiver comprises of a semiconductor photodiode, preamplifier in the electric domain, digital logic circuits, and an off-chip electronic driver circuit. This chapter discusses all the important aspects of photodetectors and optical receivers. The discussion begins with basic concepts behind the photo detection process, followed by description of different types of photodetectors usually used by optical receivers. Next, the components used in an optical receiver unit are explained. Finally, different types of noise sources in optical receivers that limit the signal-to-noise ratio, the receiver sensitivity parameter and its degradation are covered in sufficient detail.
关键词： Semiconductor Photodetectors,Noise Performance,Quantum Efficiency,Photodetectors,Avalanche Photodiode (APD),p–i–n Photodiode,Receiver Sensitivity,Responsivity,Optical Receivers
更新于2025-09-12 10:27:22
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The Effect of Inductively Coupled Plasma Etching on the I–V Curves of the APD with GaN/AlN Periodically‐Stacked‐STRUCTURE
摘要： Inductively Coupled Plasma (ICP) is widely used in dry etching of III-nitride materials, wherein the etching parameters of GaN and AlN are very different. In this paper, the ICP dry etching process parameters of GaN/AlN periodically-stacked-structure (PSS) for avalanche photodiode fabrication have been intensively studied and optimized. The flow rate ratio of Cl2/BCl3/Ar plasma, bias voltage, and the GaN-to-SiNx selectivity of ICP etching were optimized to achieve excellent surface morphology and nearly vertical sidewalls. It was found that the etching rate and the etched surface roughness of GaN/AlN material were significantly influenced by the flow rate of Cl2. After optimizing the etching procedure, the root-mean-square roughness (RMS) of the etched surface was measured to be 1.46 nm, which is close to the as grown surface. By employing the optimized ICP dry etching in the fabrication of the GaN/AlN PSS avalanche photodiode (APD), the dark current was suppressed from 3.6 A/cm2 to 8.2×10-3 A/cm2 at -90 V.
关键词： GaN/AlN,dark current,molecular beam epitaxy,inductively coupled plasma,avalanche photodiode
更新于2025-09-12 10:27:22
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Simulations of Nanoscale Room-Temperature Waveguide-Coupled Single-Photon Avalanche Detectors for Silicon-Photonic Sensing and Quantum Applications
摘要： Photonic qubits can represent an ideal choice in quantum-information science since photons travel at the speed of light and interact weakly with the environment over long distances. In this context, technological platforms allowing the development and implementation of chip-scale integrated-photonics represent a possible solution towards scalable quantum networking schemes. However, at present, most examples of integrated quantum photonics still require the coupling of light to external photodetectors operating at very low temperatures. In this paper, we demonstrate that the GeSn/Si-in-SOI technological platform can be a good candidate to realize integrated single-photon avalanche detectors (SPADs), operating at room temperature. Thus, we report the design and simulation of waveguide-based SPADs for operation at 1550 nm and 2000 nm wavelengths. We calculate the breakdown voltage, the dark count rate (DCR), the single photon detection efficiency (SPDE), the noise equivalent power (NEP), the dark count and the afterpulsing probabilities by simulating the avalanche process and the statistical features in a self-consistent way. The PIPIN SPAD performance parameters are estimated as a function of the GeSn’s threading dislocation density and of the temperature. We also demonstrate that for operation at 1550 nm and 2000 nm wavelengths with the 220-nm GeSn separate-absorber film centered in the 250-nm-high Si waveguide end, it is possible cover a number of applications at room or near room temperature, ranging from ultra-sensitive LIDAR to quantum communications, metrology, sensing and key distribution.
关键词： Optoelectronic and Photonic device,Photonic integrated circuits,Silicon Photonics,Photodetector,Avalanche photodiode
更新于2025-09-12 10:27:22
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[IEEE 2019 Compound Semiconductor Week (CSW) - Nara, Japan (2019.5.19-2019.5.23)] 2019 Compound Semiconductor Week (CSW) - High-speed Avalanche Photodiodes based on III-V Compounds for Optical Communications
摘要： Avalanche photodiodes based on III-V-compounds feature flexibility in designing bandwidth, gain, responsivity, and linearity, which are associated with not only the thickness of each layer but also doping profiles and material options and their combinations. Here, we review the design and performance of our high-speed avalanche photodiodes that feature a unique epitaxial layer structure. Even though the APDs have a vertical illumination structure, which is essential for easy optical coupling and fabrication, their speed is high enough for operation with 100G-PAM4. We also discuss our efforts for improving linearity, which is important for operation with higher-order modulation format.
关键词： Avalanche photodiode,Optical communications systems,high speed
更新于2025-09-11 14:15:04
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Noise characteristics improvement of submicron InP/InGaAs avalanche photodiode for laser detection system
摘要： InP/InGaAs avalanche photodiodes have attracted much attention in optoelectronics and long distance optical communication systems due to their high bit rate and gain-bandwidth. In this paper, to improve the noise characteristics in laser detection systems, separate absorption, grading, charge, and multiplication InP/InGaAs avalanche photodiode (SAGCM APD) with double guard rings and three thin layers of InGaAsP has been simulated. In addition, the multiplication width of SAGCM APD has been optimized which enhances the noise characteristics. The Photocurrent and dark current are acquired as and resulting in superior electrical properties among the other works. The excess noise factor in the constant mean gain of has been reduced 10.3% in comparison with recent SAGCM APDs. The calculated results show that the reduction of dark current and the excess noise factor increase the SNR for about orders of magnitude.
关键词： InP/InGaAs avalanche photodiode,SAGCM APD,Noise characteristics,Multiplication width,Laser detection system,Signal-to-noise ratio
更新于2025-09-11 14:15:04
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[IEEE 2019 IEEE Photonics Conference (IPC) - San Antonio, TX, USA (2019.9.29-2019.10.3)] 2019 IEEE Photonics Conference (IPC) - CMOS Compatible Dual Avalanche Photodiode for Algorithmic Visible Spectral Sensing
摘要： A previously reported CMOS-compatible dual avalanche photodiode design is exploited to develop a maximum-likelihood spectral-sensing algorithm, which maps the dual photocurrents to the light’s wavelength. Optimization over the reverse biases of the two APDs yields a spectral resolution of 10 nm within 440-650 nm.
关键词： spectral sensing,maximum likelihood,smart lighting,Avalanche photodiode,silicon,dual APD,CMOS
更新于2025-09-11 14:15:04
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Near-Range Large Field-of-View Three-Dimensional Photon-Counting Imaging with a Single-Pixel Si-Avalanche Photodiode
摘要： Large field-of-view (FoV) three-dimensional (3D) photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens (CL) before the detector, the FoV is expanded to ±10°. Thanks to the high detection efficiency, the signal-to-noise ratio of the imaging system is as high as 7.8 dB even without the CL when the average output laser pulse energy is about 0.45 pJ/pulse for imaging the targets at a distance of 5 m. A 3D image overlaid with the reflectivity data is obtained according to the photon-counting time-of-flight measurement and the return photon intensity.
关键词： large field-of-view,Si-avalanche photodiode,photon-counting imaging,three-dimensional imaging
更新于2025-09-09 09:28:46
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Comparison of Modulation Techniques for Underwater Optical Wireless Communication Employing APD Receivers
摘要： In this study, we theoretically analyze the performance of an underwater optical wireless communications system using different modulation techniques and an avalanche photodiode APD receiver over underwater environment channels. Based on the LOS geometrical model and combined with signal to noise ratio model for Si and Ge APD and BER; then the impact of the distance of transmission and power of the transmitter and Jerlov water type are analyzed. The characteristics of bit error rate BER for different optical modulation techniques are studied. Simulation results indicate that the performance of H-QAM is more suited for an underwater optical wireless communication. On the other hand, the suitability of avalanche photodiodes under these modulation techniques is discussed, because the photodiode Si APD has more advantages compared with Ge APD when used in an underwater optical communication.
关键词： Avalanche photodiode APD,modulation,underwater optical communication,bit error rate BER
更新于2025-09-09 09:28:46
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To the Problem of Optimization of Parameters of a Double Heterostructure Based on Direct-Gap Semiconductors for Avalanche Photodiodes
摘要： A double heterostructure based on direct-gap semiconductors with a photoabsorption middle layer at the avalanche breakdown voltage is considered. Such structures are used in the development of avalanche photodiodes with separate absorption and multiplication regions (APD with SAMR). It is shown that impact generation of electron–hole pairs should be considered in calculating the maximum possible characteristics of APDs with SAMR even in the absorption layer; therewith, this can be performed analytically.
关键词： avalanche photodiode,avalanche breakdown,multiplication,tunneling current,double heterostructure,doping,absorption
更新于2025-09-04 15:30:14