Characterization and calibration of blind pixels in short-wave infrared InGaAs focal plane arrays

Blind pixels are an inevitable problem in short-wave infrared (SWIR) InGaAs focal plane arrays (FPAs). An experiment using a laser beam-induced current method was set up to characterize the blind pixels in InGaAs FPAs. According to the result, the blind pixels are classified into four types: single overhot pixels, single dead pixels, crossing dead pixels, and paired blind pixels. Additionally, the causes of the different types of blind pixels are analyzed. It is indicated that the blind pixels are caused by defects and impurities, disconnection of the readout circuit, unformed PN junctions, and a wrong connection between the PN junction and readout integrated circuit, respectively. Based on the characterization, a blind pixel calibration method that greatly improved the quality of images taken by InGaAs FPAs is proposed.