An innovative gas sensor with on-chip reference using a monolithic twin laser is proposed. In this sensor a monolithic twin laser generates two closer laser beams with slight different wavelengths alternatively, one p...An innovative gas sensor with on-chip reference using a monolithic twin laser is proposed. In this sensor a monolithic twin laser generates two closer laser beams with slight different wavelengths alternatively, one photodiode is used to catch both absorption and reference signals by time division multiplexing. The detection of nitrous oxide adopting this scheme using a 2.1 I^m antimonide laser and an InGaAs photodiode has been demonstrated experimentally with detection limit below i ppm. Using this on chip reference scheme the fluctuations from the optical path and devices can be compensated effectively; the sensor system is simplified distinctly.展开更多
从理论与实验两方面对截止波长为1.7μm(x=0.53),1.9μm(x=0.6)和2.2μm(x=0.7)p in InxGa1-xAs探测器性能进行了研究.对探测器暗电流的研究结果表明,扩展波长In0.6Ga0.4As,In0.7Ga0.3As探测器在反向偏置低压区,欧姆电流占据主导地位;...从理论与实验两方面对截止波长为1.7μm(x=0.53),1.9μm(x=0.6)和2.2μm(x=0.7)p in InxGa1-xAs探测器性能进行了研究.对探测器暗电流的研究结果表明,扩展波长In0.6Ga0.4As,In0.7Ga0.3As探测器在反向偏置低压区,欧姆电流占据主导地位;在反向偏置高压区,缺陷隧穿电流占主导地位;且扩展波长In0.6Ga0.4As,In0.7Ga0.3As探测器的暗电流比In0.53Ga0.47As探测器增加较大.对探测器R0A随温度及i层载流子浓度变化关系的研究结果表明,在热电制冷温度下探测器性能可得到较大提高,i层的轻掺杂可使探测器的R0A得到改善.展开更多
In this article, unique spectral features of short-wave infrared band of 1 μm–3 μm, and various applications related to the photodetectors and focal plane arrays in this band, are introduced briefly. In addition, t...In this article, unique spectral features of short-wave infrared band of 1 μm–3 μm, and various applications related to the photodetectors and focal plane arrays in this band, are introduced briefly. In addition, the different material systems for the devices in this band are outlined. Based on the background, the development of lattice-matched and wavelengthextended InGaAs photodetectors and focal plane arrays, including our continuous efforts in this field, are reviewed. These devices are concentrated on the applications in spectral sensing and imaging, exclusive of optical fiber communication.展开更多
The subband energy and lasing wavelength of compressively strained triangular Ino.53Ga0.47As/InAs quantum well are calculated and compared with the conventional rectangular ones with the same strain contents. The stra...The subband energy and lasing wavelength of compressively strained triangular Ino.53Ga0.47As/InAs quantum well are calculated and compared with the conventional rectangular ones with the same strain contents. The strain compensation using Al0.33In0.36Ga0.31As barrier is introduced. The results show that lasing wavelength can be extended dramatically to beyond 2.8μm by changing the energy band from the conventional rectangular shape to a triangular one, the realization of such a structure using molecular beam epitaxy technology is also discussed.展开更多
A tunable diode laser absorption spectroscopy nitrous oxide gas sensor at 2.1 micrometres using one antimonide twin laser chip and one InGaAs photodiode is demonstrated, in which time multiplexing techniques are adopt...A tunable diode laser absorption spectroscopy nitrous oxide gas sensor at 2.1 micrometres using one antimonide twin laser chip and one InGaAs photodiode is demonstrated, in which time multiplexing techniques are adopted to acquiring both the absorption and reference signal in a robust fluctuation tolerable scheme. Electronics in analogue modality is developed to extracting absorption information and compensating for fluctuations, resulting in a direct analogue voltage output corresponding to the target gas concentration in real time. The performance of the gas sensor is evaluated experimentally, the validity and feasibility of this scheme is also discussed.展开更多
We report on InP-based metamorphic InGaAs photodiodes grown by gas source molecular beam epitaxy （MBE）, in which a relatively thin compositional graded wide band-gap InxAl1-xAs buffer layer is adopted. In the photod...We report on InP-based metamorphic InGaAs photodiodes grown by gas source molecular beam epitaxy （MBE）, in which a relatively thin compositional graded wide band-gap InxAl1-xAs buffer layer is adopted. In the photodiodes, InAiAs is also taken as cap layers, so this structure is suitable for both front and back illuminations. At room temperature the photodiodes show 50% cut-off wavelength of 2.66μm, with measured peak detectivity of 4.91×10^9 cmHz^1/2/W at 2.57μm, and the typical dark current and RoA are 7.68μA/0.94Ωcm^2 and 291 nA/24.29Ωcm^2 at 290 K and 150 K respectively for the devices in diameter 300 μm. Their performances are compared to the 2.5μm cut-off photodiodes with similar structures.展开更多
文摘An innovative gas sensor with on-chip reference using a monolithic twin laser is proposed. In this sensor a monolithic twin laser generates two closer laser beams with slight different wavelengths alternatively, one photodiode is used to catch both absorption and reference signals by time division multiplexing. The detection of nitrous oxide adopting this scheme using a 2.1 I^m antimonide laser and an InGaAs photodiode has been demonstrated experimentally with detection limit below i ppm. Using this on chip reference scheme the fluctuations from the optical path and devices can be compensated effectively; the sensor system is simplified distinctly.
文摘从理论与实验两方面对截止波长为1.7μm(x=0.53),1.9μm(x=0.6)和2.2μm(x=0.7)p in InxGa1-xAs探测器性能进行了研究.对探测器暗电流的研究结果表明,扩展波长In0.6Ga0.4As,In0.7Ga0.3As探测器在反向偏置低压区,欧姆电流占据主导地位;在反向偏置高压区,缺陷隧穿电流占主导地位;且扩展波长In0.6Ga0.4As,In0.7Ga0.3As探测器的暗电流比In0.53Ga0.47As探测器增加较大.对探测器R0A随温度及i层载流子浓度变化关系的研究结果表明,在热电制冷温度下探测器性能可得到较大提高,i层的轻掺杂可使探测器的R0A得到改善.
基金Supported by the National Basic Research Program of China under grant No.2012CB619200the National Natural Science Foundation of China under grant No.61275113 and 61204133
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFB0402400)the National Natural Science Foundation of China(Grant Nos.61675225,61605232,and 61775228)the Shanghai Rising-Star Program,China(Grant No.17QA1404900)
文摘In this article, unique spectral features of short-wave infrared band of 1 μm–3 μm, and various applications related to the photodetectors and focal plane arrays in this band, are introduced briefly. In addition, the different material systems for the devices in this band are outlined. Based on the background, the development of lattice-matched and wavelengthextended InGaAs photodetectors and focal plane arrays, including our continuous efforts in this field, are reviewed. These devices are concentrated on the applications in spectral sensing and imaging, exclusive of optical fiber communication.
文摘The subband energy and lasing wavelength of compressively strained triangular Ino.53Ga0.47As/InAs quantum well are calculated and compared with the conventional rectangular ones with the same strain contents. The strain compensation using Al0.33In0.36Ga0.31As barrier is introduced. The results show that lasing wavelength can be extended dramatically to beyond 2.8μm by changing the energy band from the conventional rectangular shape to a triangular one, the realization of such a structure using molecular beam epitaxy technology is also discussed.
文摘A tunable diode laser absorption spectroscopy nitrous oxide gas sensor at 2.1 micrometres using one antimonide twin laser chip and one InGaAs photodiode is demonstrated, in which time multiplexing techniques are adopted to acquiring both the absorption and reference signal in a robust fluctuation tolerable scheme. Electronics in analogue modality is developed to extracting absorption information and compensating for fluctuations, resulting in a direct analogue voltage output corresponding to the target gas concentration in real time. The performance of the gas sensor is evaluated experimentally, the validity and feasibility of this scheme is also discussed.
文摘We report on InP-based metamorphic InGaAs photodiodes grown by gas source molecular beam epitaxy （MBE）, in which a relatively thin compositional graded wide band-gap InxAl1-xAs buffer layer is adopted. In the photodiodes, InAiAs is also taken as cap layers, so this structure is suitable for both front and back illuminations. At room temperature the photodiodes show 50% cut-off wavelength of 2.66μm, with measured peak detectivity of 4.91×10^9 cmHz^1/2/W at 2.57μm, and the typical dark current and RoA are 7.68μA/0.94Ωcm^2 and 291 nA/24.29Ωcm^2 at 290 K and 150 K respectively for the devices in diameter 300 μm. Their performances are compared to the 2.5μm cut-off photodiodes with similar structures.
