1 July 1990 Phase-shift analysis of beat frequency in an optical heterodyne interferometer
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Proceedings Volume 1319, Optics in Complex Systems; (1990) https://doi.org/10.1117/12.22260
Event: 15th International Optics in Complex Systems, 1990, Garmisch, Germany
Abstract
An heterodyne interferoaeter is constructed with a sodulated laser diode (LD) in a Michelson interferoaeter. Phase drift of beat frequency with teiperature and its affection aechanis is discussed and a method elisinating the affection aentioned above is proposed. 1 . OPTICAL HETERODYNE INTERFEROMETER Optical frequency of laser diode can be linearly aodulated by an injection current. An optical heterodyne interferoseter is constructed with a modulated laser diode in a Michelson interferoseter. If a difference exists between two arms in the interferometer a optical beat frequency phenoaenon will be forRed. The beatfrequency signal can be detected with a photoelectric device. The output signal can be described by the following equation: 1g10[1+cos(2xfbt+t)J (1) and fb is given by fb 6f''8Lf. I C (2) Where f is the aaxiRua optical frequency variation value of wxiulated laser fb the beat frequency value fa the odulated signal frequency L the optical path difference between two aras in the interferoaeter C optical wave speed. 2. VARIATION OF BEAT FREQUENCY PHASE WITh TEMPERATURE It is well known that the optical frequency of a laser diode is affected by the tesperature (in the equation (1)) ay be changed with the variation of central wavelength of . odulated optical frequency. t aay be expressed in the for. : Li A242Ai t 2ir( ) (3) AiA2 The plus and ainus . arks in the equation above are corresponding to the upward
© (1990) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Dacheng Li, Dacheng Li, Yong Xu, Yong Xu, Jia Wang, Jia Wang, Enyou Zhang, Enyou Zhang, Mang Cao, Mang Cao, } "Phase-shift analysis of beat frequency in an optical heterodyne interferometer", Proc. SPIE 1319, Optics in Complex Systems, (1 July 1990); doi: 10.1117/12.22260; https://doi.org/10.1117/12.22260
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