Low-Noise Detector Arrays for Raman Spectroscopy

We propose to demonstrate near infrared (NIR) sensor arrays with 10 times lower noise than arrays presently available to improve the sensitivity of current spectroscopy systems. Such an achievement would allow the measurement of new phenomena through Raman spectroscopy and other diagnostic techniques. The low noise performance is enabled by the use of low-noise Si readout integrated circuits mated to low-capacitance InGaAs detector arrays. Arrays using these two technologies have never been combined for spectroscopy applications. The new InGaAs sensor array is expected to achieve less than 20 electrons of read noise and quantum efficiency of greater than 80% at 77K. Such a sensor would directly lead to higher sensitivity than presently available at low light levels, thereby improving spectroscopic systems ability to detect signals that were previously masked. The end product will be a 27 x 1380 pixel 2D InGaAs array on an 18.5 um pitch with less than 20 electrons/pixel/frame at liquid nitrogen temperature (~77K) and a 60 Hz frame rate, delivered in a cryogenic dewar.