High-sensitivity, wide-dynamic-range avalanche photodiode pixel design for large-scale imaging arrays

摘要

We present a detailed design study for a novel solid-nstate focal plane array of silicon avalanche photodiodes (APDs),nwith each detector in the array capable of operating with wide dy-nnamic range in linear or Geiger-mode. The detector array is basednon back-illuminated, crystallographically etched, (100) epitaxial sili-ncon on R-plane sapphire substrates using 27 u0001m pixels, althoughnother sizes could be supported as well. Analysis of the APD pixelndesign, which includes the photoelectron noise, dark current noise,nand electronic circuit noise, shows the capability of imaging with ansignal-to-noise ratio greater than 7 at −30 °C and ultralow illumi-nnance of 10−4 lux. The detector array design will enable large focalnplanes, capable of imaging with high sensitivity and high speed,nover a wide range of natural illumination conditions from direct sun-nlight to a cloudy moonless night.