Determination of substitutional carbon in SI-GaAs thin wafers was investigated by FT-IR microscope at room temperature for the first time. The experimental results showed that the carbon concentration in GaAs thin waf...Determination of substitutional carbon in SI-GaAs thin wafers was investigated by FT-IR microscope at room temperature for the first time. The experimental results showed that the carbon concentration in GaAs thin wafers can be measured directly with simple treatment. The calculation method of carbon concentration is in agreement with that for normal IR spectrum with 0.5cm-1 resolution. The resolution of 1cm-1 can be taken in order to obtain a high signal-to-noise (S/N) ratio using 2.34×1016 cm-2 calibration factor for calculating carbon concentration at room temperature.展开更多
Infrared signatures of aircraft are the basis for detection and monitoring. In past years, most of the studies focused on the aircraft＇s infrared signature in the mid-wave spectral region and long-wave spectral regio...Infrared signatures of aircraft are the basis for detection and monitoring. In past years, most of the studies focused on the aircraft＇s infrared signature in the mid-wave spectral region and long-wave spectral region for missile guidance or aircraft survivability studies. For the security of civil aviation, methods and instruments that can detect and monitor aircrafts from space are expected to be developed in the coming years. A short-wave infrared hyperspectral imager aboard the Tiangong-1 spacecraft acquired some civil aircraft＇s spectral data. The differences between the aircraft and the background in their spectral signatures are analyzed and discussed. Less absorption in the vapor absorption bands and a reflection spike is discovered at the 1.84 μm spectral band. The result shows that 1.84 μm and other vapor absorption bands can make contributions to aircraft detection in the daytime.展开更多
文摘Determination of substitutional carbon in SI-GaAs thin wafers was investigated by FT-IR microscope at room temperature for the first time. The experimental results showed that the carbon concentration in GaAs thin wafers can be measured directly with simple treatment. The calculation method of carbon concentration is in agreement with that for normal IR spectrum with 0.5cm-1 resolution. The resolution of 1cm-1 can be taken in order to obtain a high signal-to-noise (S/N) ratio using 2.34×1016 cm-2 calibration factor for calculating carbon concentration at room temperature.
基金supported by the Innovation Funds from Chinese Academy of SciencesChinese Manned Space Engineering, who funded the R&D of the high-resolution hyperspectral imager
文摘Infrared signatures of aircraft are the basis for detection and monitoring. In past years, most of the studies focused on the aircraft＇s infrared signature in the mid-wave spectral region and long-wave spectral region for missile guidance or aircraft survivability studies. For the security of civil aviation, methods and instruments that can detect and monitor aircrafts from space are expected to be developed in the coming years. A short-wave infrared hyperspectral imager aboard the Tiangong-1 spacecraft acquired some civil aircraft＇s spectral data. The differences between the aircraft and the background in their spectral signatures are analyzed and discussed. Less absorption in the vapor absorption bands and a reflection spike is discovered at the 1.84 μm spectral band. The result shows that 1.84 μm and other vapor absorption bands can make contributions to aircraft detection in the daytime.
