| 摘要 |
An out of plane ring laser gyroscope comprises a frame and a cavity formed in the frame to provide a non-planar closed optical pattern. A gain medium produces two light beams propagating in opposite directions in the cavity. A magnetic device applies an axial magnetic field to the gain medium to allow only light of opposite circular polarizations to lase in opposite directions. The gain medium and resonant cavity alone will allow left and right circularly polarized modes to lase in both clockwise and anticlockwise directions simultaneously. The application of the axial magnetic field to the gain region shifts the center of the gain profile for the clockwise right circularly polarized and anticlockwise left circularly polarized beams with respect to the gain profile center for the anticlockwise right circularly polarized and clockwise left circularly polarized beams. The cavity length can then be adjusted so that lasing action in two of the four modes is suppressed leaving only modes of opposite polarization propagating in opposite directions. The out of plane geometry of the cavity forces these modes to resonate at greatly different frequencies and hence prevents frequency locking over a very large range of input rotation rates.
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