Solid-state detectors for infrared radiometry

Self Cite

The paper reviews some of the advances in optical radiation measurements made over the last twenty years, particularly through the use of cryogenic radiometers and solid-state detector transfer standards. The way in which base scales of many optical radiation measurements are linked and the prospects for a further improvement in accuracy, particularly by the measurement of sources using well-characterized filter radiometers, are discussed.

Section: Transfer Standard Detectorsmentioning

confidence: 99%

Section: Transfer Standard Detectorsmentioning

confidence: 99%

Radiometry with cryogenic radiometers and semiconductor photodiodes

Fox¹

1995

Self Cite

“…The responsivity of HgCdTe detectors also depends on the quantum efficiency, the effective minority carrier lifetime, and other parameters that vary with the optical absorption coefficient. The spatial uniformity of the responsivity of HgCdTe detectors at long wavelengths has been reported by the National Physical Laboratory [9,10] but not the angular dependence.…”

Section: Introductionmentioning

confidence: 99%

Spatial and angular responsivity measurements of photoconductive HgCdTe LWIR radiometers

Gong¹,

Hanssen²,

Eppeldauer³

2004

Several newly developed large area photoconductive (PC) mercury cadmium telluride (HgCdTe) radiometers have been tested for spatial and angular responsivity for the purpose of determining what mode of operation (or radiometric quantity) could provide the lowest measurement uncertainty. An infrared (IR) test facility has been developed for the characterization of long wavelength IR (LWIR) detectors and radiometers for spatial response uniformity in power measurement mode and angular responsivity in both power and irradiance measurement modes. We have measured 34% to 53% spatial response non-uniformities and 1.5% to 10.5% changes in angular power reponsivity at different beam positions within the f /4 field-of-view (FOV) of the PC HgCdTe radiometers. The lowest responsivity uncertainty is achieved when these non-uniform radiometers are operated in irradiance measurement mode, where the incident uniform field of radiation averages out the detector's non-uniformity related uncertainties. The angular response deviation from the cosine function within the 16˚FOV of the radiometers dominates the uncertainty budget for irradiance responsivity measurements in the 3 µm to 20 µm sensitivity range of these working standard devices.

“…The purpose of this paper is to catalogue typical spatial uniformities of various photodiodes. Spatial uniformity of photodiode responsivity has been reported in several papers [2][3][4][5][6][7]. Two papers have suggested different methods to quantify the uniformity [8,9].…”

Section: Introductionmentioning

confidence: 99%

Spatial uniformity of responsivity for silicon, gallium nitride, germanium, and indium gallium arsenide photodiodes

Larason¹,

Bruce²

1998

For almost a decade, the National Institute of Standards and Technology (NIST) has supplied to its customers calibrated photodiode standards and special tests of photodetectors for absolute spectral responsivity from 200 nm to 1800 nm. During this time spatial responsivity measurements have been made on several dozen Hamamatsu silicon S1337-1010BQ photodiodes. We have found that the spatial responsivity changes with wavelength, sometimes significantly as the wavelength approaches the bandgap. The most significant changes appear to be caused by defects in the photodiode material and are not apparent over most of the wavelength region where the photodiode operates. The change in spatial uniformity with wavelength can significantly contribute to measurement uncertainties. These measurements have been repeated and the spatial responsivities have remained constant over several years. Measurements have also been made on other types of Si, GaN, Ge, and InGaAs photodiodes. The measurement equipment, method, and results are presented.