Noise measurements of a phase fluorometric instrument

Holavanahali, Raja and Carter, Gary and Bambot, Shabbir B and Venkatesh, Vadde and Srinivas, Vivek (1996) Noise measurements of a phase fluorometric instrument. In: Optical Engineering, 35 (2). pp. 549-553.

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Abstract

We present noise measurements of a phase fluorometric oxygen sensor that sets the limits of accuracy for this instrument. We analyze the phase sensitive detection measurement system with the signal ''shot'' noise being the only significant contribution to the system noise. Based on the modulated optical power received by the photomultiplier, the analysis predicts a noise spectral power density that was within 3 dB of the measured power spectral noise density. Our results demonstrate that at a received optical power of 20 fW the noise level was low enough to permit the detection of a change oxygen concentration of 1% at the sensor. We also present noise measurements of a new low-cost version of this instrument that uses a photodiode instead of a photomultiplier. These measurements show that the noise for this instrument was limited by noise generated in the preamplifier following the photodiode. (C) 1996 Society of Photo-Optical Instrumentation Engineers.

Item Type:	Journal Article
Publication:	Optical Engineering
Publisher:	The International Society for Optical Engineering
Additional Information:	Copyright of this article belongs to The International Society for Optical Engineering.
Department/Centre:	Division of Electrical Sciences > Electrical Communication Engineering
Date Deposited:	06 May 2011 05:33
Last Modified:	06 May 2011 05:33
URI:	http://eprints.iisc.ac.in/id/eprint/37419

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