| 摘要 |
<p>In the rotation rate measuring instrument, two component beams derived from a light beam produced by a laser circulate around a coiled optical waveguide (radius R, length L) in opposite directions. From the phase difference between the two component beams due to the Sagnac effect, the rotation rate is determined. Before entering the optical waveguide, each of the two component beams is modulated in a modulator (5, 6) such that the phase differences (2 nu +1) pi /2, (2 nu +5) pi /2, and (2 nu +3) pi /2 (where nu is an arbitrary integer) exist periodically between the two component beams emerging from the optical waveguide. The drive signals for the two modulators, which exhibit periodic frequency changes of 2F, are varied in such a way that the output of an optical-to-electrical transducer (2) to which the two component beams are directed after travelling around the optical waveguide provides a constant signal. To compensate for the Sagnac phase difference, an additional frequency difference of DELTA f is required between the two drive signals. The rotation rate OMEGA is determined by the equation <IMAGE> where lambda =vacuum wavelength of the light, and C=velocity of light in vacuo.</p> |
