<title>High-performance infrared detectors at Sofradir</title>

Abstract

The performance of an InfraRed (IR) system is based on a high spatial resolution and on a high thermal resolution.An increase in spatial resolution means an increase in number of pixels, a decrease in detector pitch and an increase in the detector pixel MTF. Regarding thermal resolution increase, it will be achieved mainly by an increase in the maximum quantity of charges which can be stored in the silicon read-out circuits for 2D staring arrays.At present, only cooled detectors answer this need of high performance detectors, such as 2D arrays with TV format resolution and high NETD.In this paper these trends regarding high performance are discussed and recent IRFPA results at Sofradir are presented.Finally, a comparison with uncooled detectors, also processed at Sofradir, is presented, to outline the remaining gap between both types of detectors.

A new readout integrated circuit for long-wavelength IR FPA

“…Here, the integration time is defined by ROIC charge capacity. Inspection of curves 3-5 shows that already at k P 3.2 lm the noise equivalent temperature difference starts exhibiting a substantially modified behavior as a function of k. Under the condition of limited ROIC charge capacity, as the wavelength k increases, the noise equivalent temperature difference of ''real" thermography systems becomes seriously deteriorated [2]. For the rightmost points in curves 3-5 the integration time is 630-100 ls, this time being shorter than the time required for reading one matrix row.…”

“…Few still unsolved problems involve the development of hybrid FPA-based far-IR thermography systems with maximum theoretically possible NETD figures. It should be noted that it is the read-out-circuit charge storage capacity, instead of the photoelectric characteristics of photodiodes, that imposes limitations on the performance of thermography systems intended for operation in the far-IR region [2].…”

Megapixel HgCdTe MWIR focal plane array with a 15-μm pitch

“…As a matter of fact, for the long IR waveband, linear arrays are close to the theoretical limit regarding spatial and thermal performance [2] and have demonstrated their ability to answer all the high performance system needs including ruggedness regarding environmental conditions, high blooming levels and optical counter measures.…”

Hybrid IR FPAs based on charge injection devices

“…Analysis noise equivalent temperature difference (NETD) of thermographic systems depending on spectral range and charge capacity of ROIC was carried out in a number of papers [1][2][3][4][5]. In Fig.…”