Quantix and Intrapix: test benches dedicated to quantum efficiency measurement and intra-pixel response of detectors from VIS to LWIR

Abstract

Absolute Quantum Efficiency (QE) measurements are very demanding. To measure the QE of detectors from 0.8μm to 12.5μm a dedicated test bench has been built. The Quantix test bench relies on an optical design ensuring a uniform flat-field illumination of the detector. The illumination uniformity was measured with photodiodes built and calibrated at CEA/LETI. While performing QE measurements, the calibrated photodiode is placed in the vicinity of the detector to measure the incident flux. The Quantix test bench has been validated with a detector whose QE has been measured at the European Space Agency. In this paper, the test bench will be described in details and QE measurements performed on near infrared, MCT-based detectors will be presented. The intra-pixel response is also an important parameter to know as it can affect the accuracy of photometric and shape measurements. The Intrapix test bench has been specifically designed for this measurement, using the Talbot effect to simultaneously measure the intra-pixel response in a large number of subareas of a given detector, from 0.5 μm to 12 μm. The paper will give a brief status of the test bench development.