Invention Grant
US4781425A Fiber optic apparatus and method for spectrum analysis and filtering
失效
用于频谱分析和滤波的光纤设备和方法
- Patent Title: Fiber optic apparatus and method for spectrum analysis and filtering
- Patent Title (中): 用于频谱分析和滤波的光纤设备和方法
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Application No.: US830457Application Date: 1966-02-18
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Publication No.: US4781425APublication Date: 1988-11-01
- Inventor: William P. Risk , Gordon S. Kino
- Applicant: William P. Risk , Gordon S. Kino
- Applicant Address: CA Stanford
- Assignee: The Board of Trustees of the Leland Stanford Junior University
- Current Assignee: The Board of Trustees of the Leland Stanford Junior University
- Current Assignee Address: CA Stanford
- Main IPC: G01J3/02
- IPC: G01J3/02 ; G01J3/12 ; G01J3/447 ; G01J9/00 ; G02B6/10 ; G02B6/34 ; G02F1/01 ; G02F1/11
Abstract:
An acousto-optic frequency shifter having a long interaction region is used as an optical analyzer. A variable frequency signal generator is used to drive an acoustic transducer to launch an acoustic wave in contact with an optical fiber. The acoustic frequency is varied over a known range to generate acoustic waves having known wavelengths. An optical signal having an unknown optical wavelength is introduced into one end of the optical fiber in a first polarization mode. The effect of the acoustic wave on the optical signal is to cause coupling of the optical signal from the first polarization mode to a second orthogonal polarization mode. The amount of the coupling is dependent upon the phase-matching between the acoustic wavelength and the optical beat length. The coupling between the polarization modes is maximum when the acoustic wavelength is equal to the optical beat length. The intensity of the optical signal coupled to the second polarization mode can be measured to determine the optical wavelength corresponding to the acoustic wavelength when the maximum intensity occurs.
Public/Granted literature
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