| 摘要 |
<p>A phase modulator (86, 64, 66, 68) applies sequences of artificial phase shifts in the region of overmodulation between light beams counterpropagating within the sensor coil (40, 42, 44) of a Sagnac interferometer to obtain improved random walk performance. The sequences are composed of phase shifts of +/-a pi /2b and +/-(4b-a) pi /2b where a is an odd integer and b is an integer greater than 1. The waveform for driving the phase modulator is derived from a 2 pi radian mapping plotted so that adjacent driving signal values differ by a pi /2b or -(4b-a) pi /2b in a first angular direction and by -a pi /2b or by (4b-a) pi /2b in the opposite angular direction. Angular transitions about the mapping may be predetermined to generate a deterministic, random, or pseudo-random modulation sequence. In the event that a deterministic sequence is chosen, it is examined for orthogonality properties to assume zero average output bias from crosstalk. <IMAGE></p> |
