| 1. |
- Huang, Weiguo, et al.
(författare)
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InAs quantum wells grown on GaP/Si substrate with Ga(In,As)P metamorphic buffers
- 2022
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Ingår i: Hongwai Yu Haomibo Xuebao/Journal of Infrared and Millimeter Waves. - 1001-9014. ; 41:1, s. 253-261
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Tidskriftsartikel (refereegranskat)abstract
- InAs/In0.83Al0.17As quantum wells have been demonstrated on In0.83Al0.17As metamorphic layers on GaP/Si substrates. The effects of GaxIn1-xP and GaAsyP1-y graded buffer layers on the sample performances are investigated. The sample with GaxIn1-xP metamorphic buffer layer has narrower width in X-ray diffraction reciprocal space maps, indicating less misfit dislocations in the sample. Mid-infrared photoluminescence signals have been observed for both samples at room temperature, while the sample with GaxIn1-xP metamorphic buffer shows stronger photoluminescence intensity at all temperatures. The results indicate the metamorphic buffers with mixed cations show superior effects for the mid-infrared InAs quantum wells on GaP/Si composite substrates.
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| 2. |
- Yang Song-Yuan,, et al.
(författare)
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A D-band communication transmitter module with a novel self-aligned microstrip line-to-waveguide transition
- 2019
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Ingår i: Hongwai Yu Haomibo Xuebao/Journal of Infrared and Millimeter Waves. - 1001-9014. ; 38:3, s. 296-302
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Tidskriftsartikel (refereegranskat)abstract
- A D-band (110 similar to 170 GHz) transmitter module, based on a novel self-aligned microstrip-to-waveguide transition, was demonstrated. The simulated average insertion loss of the transition is about 0.6 dB and return loss is better than 10 dB during working band. A D-band transmitter module was developed using such transition with resistive mixer and multiplier chips. The transmitter module operates between 110 similar to 153 GHz and provides a peak saturated output power of -4.6 dBm at 150 GHz and with 13.5 GHz 3 dB bandwidth from 145.8 to 159.3 GHz. 3 Gb/s wireless communication with this module at 145 GHz was demonstrated with spectrum efficient 64-QAM modulation.
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| 3. |
- Fu, Ying, et al.
(författare)
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Modification of absorption spectrum of GaAs/AlGaAs quantum well infrared photodetector by postgrowth adjustment
- 2006
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Ingår i: Hongwai yu haomibo xuebao. - 1001-9014. ; 25:1, s. 1-5
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Tidskriftsartikel (refereegranskat)abstract
- Quantum well intermixing techniques modify the geometric shape of quantum wells to allow postgrowth adjustments. The tuning effect on the optical response property of a GaAs/AlGaAs quantum well infrared photodetector (QWIP) induced by the interdifussion of Al atoms was studied theoretically. By assuming an improvement of the heterointerface quality and an enhanced Al interdiffusion caused by postgrowth intermixings, the photoluminescence spectrum shows a blueshifted, narrower and enhanced photoluminescence peak. The infrared optical absorption spectrum also shows the expected redshift of the response wavelength. However, the variation in the absorption peak intensity depends on the boundary conditions of the photo generated carriers. For high-quality QWIP samples, the mean free path of photocarriers is long so that the photocarriers are largely coherent when they transport across quantum wells. In this case, the enhanced Al interdiffusion can significantly degrade the infrared absorption property of the QWIP. Special effects are therefore needed to maintain and/or improve the optical properties of the QWIP device during postgrowth treatments.
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| 4. |
- Fu, Y, et al.
(författare)
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Optical spectra of low-dimensional semiconductors
- 2003
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Ingår i: Hongwai yu haomibo xuebao. - : Science Press. - 1001-9014. ; 22:6, s. 401-405
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Tidskriftsartikel (refereegranskat)abstract
- We have studied the optical spectra of low-dimensional semiconductor systems by calculating all possible optical transitions between electronic states. Optical absorption and emission have been obtained under different carrier population conditions and in different photon wavelengths. The line-shapes of the peaks in the optical spectrum are determined by the density of electronic states of the system, and the symmetries and intensities of these peaks can be improved by reducing the dimensionality of the system. Optical gain requires in general a population inversion, whereas for a quantum-dot system, there exists a threshold value of the population inversion.
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| 5. |
- Fu, Y, et al.
(författare)
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Quantum mechanical model and simulation of GaAs/AlGaAs quantum well infrared photodetector-I optical aspects
- 2002
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Ingår i: Hongwai yu haomibo xuebao. - : Science Press. - 1001-9014. ; 21:5, s. 321-326
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Tidskriftsartikel (refereegranskat)abstract
- A complete quantum mechanical model for GaAs/AlGaAs quantum well infrared photodetectors(QWIPs) is presented here. The model consisted of four parts: (1) Starting with the description of the electromagnetic field of the infrared radiation in the QWIP, effective component of the vector potential [\A(z)\] along the QWIP growth direction (z-axis) due to the optical diffraction grating was calculated. (2) From the wave transmissions and the occupations of the electronic states, it was discussed that the dark current in the QWIP is determined by the drift-diffusion current of carriers thermally excited from the ground sublevel in the quantum well to extended states above the barrier. (3) The photocurrent was investigated by the optical transition (absorption coefficient between the ground state to excited states due to the nonzero-[\A(z)\]). (4) By studying the inter-diffusion of the At atoms across the GaAs/AlGaAs heterointerfaces, the mobility of the drift-diffusion carriers in the excited states was calculated, so the measurement results of the dark current and photocurrent spectra can be explained theoretically. With the complete quantum mechanical descriptions of (1-4), QWIP device design and optimization are possible.
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| 6. |
- Fu, Y, et al.
(författare)
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Quantum mechanical model and simulation of GaAs/AlGaAs quantum well infrared photodetector-II electrical aspects
- 2002
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Ingår i: Hongwai yu haomibo xuebao. - : Science Press. - 1001-9014. ; 21:6, s. 401-407
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Tidskriftsartikel (refereegranskat)abstract
- A complete quantum mechanical model for GaAs/AlGaAs quantum well infrared photodetectors (QWIPs) was presented. The photocurrent was investigated by the optical transition( absorption coefficient) between the ground state and the excited states due to the nonzero component of the radiation field along the sample growth direction. By studying the inter-diffusion of the Al atoms across the GaAs/AlGaAs heterointer faces, the mobility of the drift-diffusion carriers in the excited states was calculated. As a result, the measurement results of the dark current and the photocurrent spectra are explained theoretically.
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