NIRSpec detectors: noise properties and the effect of signal dependent inter-pixel crosstalk

摘要

NIRSpec (Near Infrared Spectrograph) is one of the four science instruments of the James Webb Space Telescope(JWST) and its focal plane consists of two HAWAII-2RG sensors operating in the wavelength range 0.6−5.0μm.As part of characterizing NIRSpec, we studied the noise properties of these detectors under dark and illuminatedconditions. Under dark conditions, and as already known, 1/f noise in the detector system produces somewhatmore noise than can be accounted for by a simple model that includes white read noise and shot noise onintegrated charge. More surprisingly, at high flux, we observe significantly lower total noise levels than expected.We show this effect to be due to pixel-to-pixel correlations introduced by signal dependent inter-pixel crosstalk,with an inter-pixel coupling factor, α, that ranges from ~ 0.01 for zero signal to ~ 0.03 close to saturation.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.