Stabilised solid-state laser gyroscope

Abstract

The main problem with solid-state laser gyroscopes is that the optical cavity is inherently unstable. According to the invention, this instability can be reduced by controlling the propagation-direction-dependent loss of light into the chamber (1) by providing an optical unit comprising: a polarizing unit ; a first unit (7) with a reversible effect, which operates according to the polarization of the wave; and a second unit (8) with an irreversible effect, which also operates according to the polarization of the wave, wherein at least One is variable and the loss can be electronically controlled to follow the intensity difference between the counterpropagating effects. Several devices are disclosed that either use a fixed reversible effect and a variable irreversible effect or vice versa. The device is suitable for single cavity lasers, especially neodymium-doped YAG lasers and fiber cavity lasers.

Description

technical field [0001] The field of the invention is solid-state laser gyroscopes for measuring rotational speed. Such instruments are used in particular in aviation. Background technique [0002] Laser gyroscopes, designed about 30 years ago, are now widely used on a commercial scale. Its principle of operation is based on the Sagnac effect, which produces a frequency difference Δv between two light projection modes propagating in opposite directions of a bidirectionally acting laser ring cavity undergoing a rotational movement, called the counter-propagating mode. Typically, the frequency difference Δv is equal to: [0003] Δv=4AΩ / λL [0004] where L and A are the length and area of ​​the chamber, respectively; λ is the emission wavelength of the laser to exclude the Sagnac effect; and Ω is the rotational speed of the device. [0005] The [Delta]v value measured from the spectroscopic analysis of the two beam beats is used to determine the [Omega] ...

AI Technical Summary

Problems solved by technology

[0015] The additional losses introduced into the chamber by the feedback device must be of the same order of magnitude as the losses in the chamber itself;

Images