Please use this identifier to cite or link to this item: http://nopr.niscair.res.in/handle/123456789/9626
Title: Photon detectors: Thermal background noise-equivalent power with frequency-dependent detector efficiency
Authors: Raghavan, Aditya
Jha, Sudhanshu S
Keywords: Noise-equivalent-power
Thermal background noise
Photon detection
Issue Date: Oct-2004
Publisher: CSIR
Series/Report no.: H 01J 40/00
Abstract: <link rel="File-List" href="file:///C:%5CDOCUME%7E1%5Ccharu%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"> Background thermal noise often becomes the limiting factor while detecting low signals of photon flux from a distant thermal source. This cannot be eliminated by simply cooling the photodetector. A general method is developed here to calculate the background thermal noise and the noise equivalent power (NEP) for background source temperature <i>T</i>, with any given frequency-dependent quantum efficiency function <i>η(ν)</i> for the photodetector. Applications of our analysis to some specific model forms of <i>η(ν)</i>, with finite bandwidths, show that earlier calculations are highly inadequate for peak efficiency frequencies <i>ν<sub>o</sub> < k<sub>B</sub>T/h</i>, where <i>k<sub>B</sub></i> is the Boltzmann constant and <i>h</i> is the Planck constant. The NEP, which determines the limit on the lowest signal power that can be detected by any given photodetector, is much higher in these frequency regions compared to earlier approximate estimates.
Description: 722-728
URI: http://hdl.handle.net/123456789/9626
ISSN: 0975-1041 (Online); 0019-5596 (Print)
Appears in Collections:IJPAP Vol.42(10) [October 2004]

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