15{\mu}m Quantum well infrared photodetector for thermometric imagery in cryogenic windtunnel

TL;DR

This paper demonstrates that a 15μm quantum well infrared photodetector can effectively image low-temperature scenes in cryogenic wind tunnels, operating at higher temperatures and with comparable sensitivity to existing detectors.

Contribution

The study shows the viability of QWIP technology for low flux infrared detection in cryogenic environments, with a predictive model and practical imaging results.

Findings

QWIP can operate at 30K with NETD as low as 130mK

QWIP imaging is effective in cryogenic wind tunnel scenes

QWIP allows higher operating temperatures and simpler optical setups

Abstract

Quantum Well Infrared Photodetector (QWIP) usually suffer from a too moderate quantum efficiency and too large dark current which is often announced as crippling for low flux applications. Despite this reputation we demonstrate the ability of QWIP for the low infrared photon flux detection. We present the characterization of a state of the art 14.5\mu m QWIP from Alcatel-Thales 3-5 Lab. We developed a predictive model of the performance of an infrared instrument for a given application. The considered scene is a Cryogenic Wind Tunnel (ETW), where a specific Si:Ga camera is currently used. Using this simulation tool we demonstrate the QWIP ability to image a low temperature scene in this scenario. QWIP detector is able to operate at 30K with a NETD as low as 130mK. In comparison to the current detector, the temperature of use is three times higher and the use of a QWIP based camera would allow a huge simplification of the optical part.