发明名称 |
Methods and apparatus of tracking/locking resonator free spectral range and its application in resonator fiber optic gyroscope |
摘要 |
A resonator fiber optic gyroscope is provided. The resonator fiber optic gyroscope includes a gyroscope resonator, a laser; a clockwise modulator; a clockwise circulator; a clockwise reflection detector; a first-lock-in-amplifier, a clockwise-resonance-tracking servo to receive output from the first-lock-in-amplifier and to provide feedback to the laser to lock the laser to the gyroscope resonator; a clockwise transmission detector to detect an optical beam output from the counter-clockwise input port; a second servo; a second-lock-in-amplifier; and a third-lock-in-amplifier. The first and second lock-in-amplifiers demodulate at the first harmonic of the modulation frequency. The second-lock-in-amplifier demodulates at the second harmonic of the modulation frequency. Either the modulation frequency of the clockwise optical beam is locked to (n+0.5) times the FSR through the second servo, where n is zero or a positive integer, or the FSR is locked to 1/(n+0.5) times the modulation frequency of the clockwise optical beam through the second servo. |
申请公布号 |
US9001336(B1) |
申请公布日期 |
2015.04.07 |
申请号 |
US201314047855 |
申请日期 |
2013.10.07 |
申请人 |
Honeywell International Inc. |
发明人 |
Qiu Tiequn;Wu Jianfeng;Strandjord Lee K.;Sanders Glen A. |
分类号 |
G01C19/72;G01C19/66 |
主分类号 |
G01C19/72 |
代理机构 |
Fogg & Powers LLC |
代理人 |
Fogg & Powers LLC |
主权项 |
1. A resonator fiber optic gyroscope system, comprising:
a gyroscope resonator having a clockwise input port and a counter-clockwise input port and a free spectral range (FSR) corresponding to the resonator round trip length; a laser configured to couple a clockwise optical beam into to the clockwise input port; a clockwise modulator to impose a modulation frequency equivalent to (n+0.5) times the FSR on the clockwise optical beam before the clockwise optical beam is coupled into the clockwise input port, where n is zero or a positive integer; a clockwise circulator; a clockwise reflection detector to detect the clockwise optical beam output from a clockwise reflection port; a first-lock-in-amplifier to receive a signal from the clockwise reflection detector, wherein the first-lock-in-amplifier demodulates at the first harmonic of the modulation frequency of the clockwise optical beam; a clockwise-resonance-tracking servo to receive output from the first-lock-in-amplifier and to provide feedback to the laser to lock the laser to the gyroscope resonator; a clockwise transmission detector to detect an optical beam output from the counter-clockwise input port; a second servo; a second-lock-in-amplifier to receive a signal from the clockwise transmission detector, wherein the second-lock-in-amplifier demodulates at the second harmonic of the modulation frequency of the clockwise optical beam and provides feedback to the second servo; and a third-lock-in-amplifier to receive a signal from the clockwise transmission detector, wherein the third-lock-in-amplifier demodulates at the first harmonic of the modulation frequency of the clockwise optical beam and provides feedback to the clockwise-resonance-tracking servo to correct errors in a clockwise resonance tracking loop, wherein one of: the modulation frequency of the clockwise optical beam is locked to (n+0.5) times the FSR through the second servo, where n is zero or a positive integer; or the FSR is locked to 1/(n+0.5) times the modulation frequency of the clockwise optical beam through the second servo. |
地址 |
Morristown NJ US |