Optical path structure for stimulated Brillouin optical fiber gyroscope

Abstract

The invention discloses an optical path structure for a stimulated Brillouin optical fiber gyroscope. A light source emitted by an Erbium-doped narrow-linewidth optical fiber laser is split into two beams to transmit in different paths after passing through a coupler A. One beam of light enters a photonic crystal optical fiber resonant cavity after passing through an all-optical fiber acousto-optic frequency shifter, an optical fiber circulator A, a polarization controller A and a coupler B; and the other beam of light enters the photonic crystal optical fiber resonant cavity after passing through a variable attenuator, an optical fiber circulator B, a polarization controller B and the coupler B. The two beams of light are pump light transmitting anticlockwise and pump light transmitting clockwise respectively. As the wave field of the pump light in a photonic crystal optical fiber and an elastic sound wave field interact to generate stimulated Brillouin scattering, the stimulated Brillouin scattering can be described as periodical modulation of the refractive index of a medium which is caused by the nonlinear interaction performed between pump light waves and Stokes light waves through sound waves that are generated by the electrostriction of the pump light waves.

Description

technical field [0001] The present invention relates to a fiber optic gyroscope, more particularly, to an optical path structure suitable for use as a fiber optic gyroscope. Background technique [0002] The fiber optic gyroscope is a kind of all-solid-state, truly silent gyroscope. It can be divided into an optical path structure and a circuit structure according to the difference in processing information. A photodetector is used to realize the connection between the optical path structure and the circuit structure. Fiber optic gyroscope is a kind of high reliability, long life, wide dynamic range, shock and vibration resistance, small size, light weight and suitable for mass production, etc. It can achieve high precision and has become the first choice for various inertial systems. inertial instrument. [0003] The patent application publication number is CN 101067556A, and the publication date is November 7, 2007. A four-frequency differential Brillouin fiber optic gyro...

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Problems solved by technology

However, the gain medium of He-Ne laser is gas, which has poor shock and vibration resistance.

Later, Nd:YAG (neodymium-doped yttrium aluminum garnet) lasers with a wavelength of 1.32 μm were used as light sources, but Nd:YAG lasers are relatively large in size and are not suitable for the actual application requirements of miniaturized gyroscopes.

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