The application progress of single photon avalanche photodiodes in the field of low-light imaging technology

The technology of low-light imaging has garnered extensive development due to its critical role in military apparatus and contemporary combat strategies. Image intensifiers, exemplifying the sophistication of low-light imaging devices, have been integrated into various platforms including personal crash helmets and aircraft pods with their advantages of elevated gain and exceptional stability. However, the limitations of image intensifiers, such as their large size, heavy weight and inability to realize digitalization, are increasingly failing to satisfy demands of future market requirements. Single photon avalanche diode (SPAD) devices offer a high gain and single-photon detection capability that rivals that of image intensifiers thanks to the avalanche multiplication mechanism. Moreover, SPAD devices have the advantages of small size and light weight comparable to those of CMOS image sensors. Consequently, SPAD devices are deemed to be among the most prospective technologies within the domain of low-light imaging, owing to their superior attributes such as high gain, the capability of single-photon detection, high dynamic range, small size and digital image processing capabilities. In recent years, SPAD devices have been researched by global high-tech corporations, which exhibit significant application potential in various fields of optical detection and imaging, such as security surveillance, autonomous driving and biomedicine. This paper systematically introduces the fundamental principles and evolutionary trajectory of SPAD devices. Moreover, it collates and reviews the developmental strategies of several international high-tech corporations, as well as the current applications of SPAD devices over the past few years. In conclusion, the paper provides an outlook on the future development trend and technological advancements of SPAD devices within the realm of low-light imaging technology.