上海科技大学知识管理系统

The infrared detectors have come to the 3rd generation since it was first proposed. Both of the small size and large scale are the requirements for the development of infrared detectors. At present, the focal plane array devices on the market have a relatively high difference between the response wavelength and the size of pixel to avoid to effect of the diffraction which is a key effect to limit the development of the long wave detection while reducing the size of the pixel. The quantum well infrared focal plane array devices fabricated by GaAs/AlGaAs have been widely used due to high uniformity and mature technology. Until now, grating coupling is one of the most useful method to raise a high quantum efficiency, but there still some problems when fabricating smaller grating because of the complex technology and the wavelength and the size of the pixel are too close to achieve an ideal quantum efficiency because the strong diffraction effect will occur before the infrared radiation reaches the active region and result in significant crosstalk and errors. Therefore, grating coupling limits the size of the FPA and as a coupling method, it is difficult to achieve due to small pixel size. Therefore, this paper adopts the total internal reflection coupling structure proposed by K.K.Choi, and compare it with the grating coupling method to study how this structure improves the performance when detecting longwavelength and reducing the size of pixels. In this paper, the 640×512 quantum well infrared focal plane array with the center-to-center distance of 15 μm and the response wavelength of 10.55 μm is fabricated by using GaAs/AlGaAs and find a new method to fabricate the total internal reflection coupling structure. The FDTD-based open source field simulation software MEEP is used to simulate the field distribution inside this device and evaluate its performance on fighting against optical crosstalk and compare its performance with the grating coupling structure. In this paper, we also use MEEP to explore how the reflection angle, the position of the active region, and the period of the quantum well will influence the distribution of the field inside the device, and calculate the electromagnetic wave's energy of the active region as the evaluation factor. These result shows that these factors restrict each other, therefore, to produce a good QWIP FPA based on the total internal reflective structure, one need to take these factors into account to tune these parameters to maximize the optimized performance. The main content of the research is to fabricate a 640×512 total internal reflection quantum well infrared focal plane array device, and use the MEEP to study the electrical field distribution inside the device with related geometric factors. © 2023 SPIE.