Dual laser acousto-optical diffraction technique for the calibration of a CO sub 2 laser scattering apparatus

Journal Article · Sat Sep 01 00:00:00 EDT 1990 · Review of Scientific Instruments; (USA)

DOI:https://doi.org/10.1063/1.1141356· OSTI ID:6412480

Chang, L; Zeng, L; Cao, J; Yu, C; Zu, Q ^[1]

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1. Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui (People's Republic of China)

In this paper a dual laser acousto-optical diffraction technique is described that provides an absolute calibration of a CO{sub 2} laser coherent scattering apparatus and other heterodyne receivers. Rather than directly detecting the sound pressure of the acoustic field or the power diffracted from the CO{sub 2} laser beam, the sound pressure is measured with the heterodyne detection of acousto-optical diffraction from a He-Ne laser beam. Noise equivalent power (NEP) measurement of the heterodyne receiver for the CO{sub 2} laser scattering apparatus and the studies of the detector bias and local oscillator power dependence of NEP values are performed by this technique. The measured minimum NEP value (6.8{times}10{sup {minus}20} W/Hz) is very close to the quantum noise limit.

• OSTI ID: 6412480
• Journal Information: Review of Scientific Instruments; (USA), Vol. 61:9; ISSN 0034-6748
• Country of Publication: United States
• Language: English

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