Recently, type-II superlattice (T2SL) infrared detectors have drawn a lot of attention. Compared with II-VI-based HgCdTe materials, III-V-based T2SL materials (InAs/GaSb and related alloys) have higher quality, uniformity and stability. Besides, T2SL infrared (IR) detectors have flexibility in energy-band engineering. T2SL IR detectors have higher theoretically-predicted performance than HgCdTe IR detectors, and are commonly considered to be the most promising alternative for the state-of-the-art HgCdTe IR detectors. T2SL IR detectors have experienced significant progress over past few years, in areas of material epitaxy, band structure design, and device processing methods. On basis of summarizing and analyzing literature recently published, this paper presents the development history, current status and advanced technologies of T2SL IR detectors. We firstly introduce the T2SL material, working principle and its advantages. Then we review several band structures and advances of T2SL IR detectors in some famous research institutes. Finally, advanced T2SL technologies are presented, such as HOT (high-operating-temperature), dual-color and small SWaP (Size, Weight and Power) T2SL IR detectors.
As the development of space-based infrared remote-sensing technology, the application value of space-based infrared remote sensing instruments is gradually recognized in the field of military, meteorology, environment, resources and astronomical observation, which increasing the demand of space infrared remote sensing instruments. As the core component of space-based infrared remote sensing instruments, spaceborne infrared detectors have been used more and more, the spaceborne infrared detector technology has also made great progress. In this paper, the development history, current situation and development trend of space-based infrared remote sensing instruments were introduced; the key characteristics of spaceborne infrared detectors applied to pushbroom scanning infrared Imager, imaging spectrometer and staring imager were summarized, such as the photoelectric performance, pixel size, device scale, frame rate, power consumption and package; The applications of spaceborne infrared detectors made of different design of material, ROIC and package were presented, several existed technical problems were pointed out, and some future development requirements of the spaceborne infrared detector were also proposed.
The readout chain circuits for time delay integration charge coupled device camera imaging system include CCD focal plane driving circuit, analog-to-digital conversion circuit, high-speed digital data transmission circuit and other parts together. The parasitic factors such as the quality of high frequency clock, high speed data transmission error rate and the aging of printed circuit board will induce more noise to image data of camera. As the longer time circuits working, the noise of readout chain becomes bigger and bigger, then the signal-to-noise becomes worse. This paper proposed a method to make circuit system check its noise as the circuit is working, which is based on pseudo CCD-signal to check the Signal-to-Noise of readout chain of TDICCD, and sends the result to control core of the system. The paper combines the theory calculation and actual measurement as the method for testing. High precision pseudo CCD signal source is used to test the onboard circuit and circuit SNR results of readout chain, harmonic frequency, noise floor and other related parameters are automatic processed.
Current analysis was an important research content for reducing power of cryocooler’s controller. Simulation was done among load current, H bridge current and power current refer to 42V bus power voltage. Then relationship among IL1, IC1, ρ and IM1 was established. Simulation results indicate that IL1-max, IL1-ave, IL1-rms, IC1-min and IC1-ave were linearly increasing to ρ and IM1, especially IL1-rms ≈ 0.612ρ IM1-max . IC1-rms increase firstly then decrease with the increasing of ρ. IC1-rms reaches maximum when ρ=0.8, then ICL-rms =(12.32/RM1 + 0.98) exp -((ρ-0.78)/0.57)2. The results were useful for miniaturizing cryocooler’s controller.