摘要 |
<p>A ring laser rotation measuring device in which, for reducing null-shift and frequency-pulling, the laser device generates radiation propagated in opposite directions round the loop and which is amplitude modulated to produce contradirectionally propagated pulses, the depth of modulation being such that all the radiation circulating in the closed loop is incorporated in the pulses. The modulation is preferably produced by two optical modulators disposed non-symmetrically with respect to a solid state laser (Nd:YRG), which modulators are operated in synchronism to define two points in the path at equal effective distances from the laser and at which the contra-circulating pulses cross one another, there being no optical component at said points and all the optical components in the loop being separated by distances not less than the pulse length.</p> |