Development of sensitive long-wave infrared detector arrays for passively cooled space missions

Craig Mcmurtry,Richard T Demers,Aristo Yulius,Amanda K Mainzer,Meghan Dorn,Donald Lee,William J Forrest,Dennis Edwall,Chi-Yi A Chen,Candice Bacon Fazar,Fengchuan Liu,Judith L Pipher,James Beletic

doi:10.1117/1.oe.52.9.091804

Abstract

The near-earth object camera (NEOCam) is a proposed infrared space mission designed to discover and characterize most of the potentially hazardous asteroids larger than 140 m in diameter that orbit near the Earth. NASA has funded technology development for NEOCam, including the development of long wavelength infrared detector arrays that will have excellent zodiacal background emission-limited performance at passively cooled focal plane temperatures. Teledyne Imaging Sensors has developed and delivered for test at the University of Rochester the first set of approximately 10 micron cutoff, 1024 x 1024 pixel HgCdTe detector arrays. Measurements of these arrays show the development to be extremely promising: noise, dark current, quantum efficiency, and well depth goals have been met by this technology at focal plane temperatures of 35 to 40 K, readily attainable with passive cooling. The next set of arrays to be developed will address changes suggested by the first set of deliverables.

Highlights

Requirements on Long-Wavelength Detector ArraysThe continued advancement of space-based astronomy/planetary science depends critically on the development of improved detector array technology
The recently launched wide-field infrared survey explorer (WISE)[1] mission achieved point-source sensitivities that were improved by hundreds of times over the infrared astronomical satellite (IRAS)[2] which launched in 1983, despite the fact that the IRAS telescope’s primary mirror was larger than WISE’s (60 cm versus 40 cm)
near-earth object camera (NEOCam) is a 0.5 m space telescope with a single imaging instrument operating at two wavelength ranges: 4 to 5 μm and 6 to 10 μm

Summary

Introduction

Planetary science depends critically on the development of improved detector array technology. WISE,[14] the Hubble space telescope’s wide-field camera[3,15] and the JWST.[16,17] The HAWAII arrays have demonstrated the low power dissipation needed to support passive cooling as well as the low noise performance required to detect faint, natural background-limited astronomical sources and the narrow range of actual detector biases needed for operation of longer-wave HgCdTe photodiodes with a source-follower per detector ROIC. In 2010, the NASA Discovery program awarded the NEOCam project technology funding to support the development of megapixel HgCdTe arrays operating with low noise and low dark current at wavelengths out to ∼10 μm or beyond at focal plane temperatures that could be achieved with passive cooling. Note that ∼90% of the pixels show dark currents

Prior Development

H1RG-16885

H1RG-16887

Findings

Summary