Sagnac theory, interference theory.
The main point of Sagnac’s theory is this: when the light beam travels in a ring-shaped channel, if the ring channel itself has a rotation speed, the time required for the light to travel in the direction of rotation of the channel is longer than that along the channel It takes more time to rotate in the opposite direction.
When the optical loop rotates, the optical path of the optical loop will change relative to the optical path of the loop at rest in different directions of advancement. Using this change in optical path, if interference is caused between light traveling in different directions to measure the rotational speed of the loop, an interferometric fiber optic gyroscope can be manufactured. If this change in loop optical path is used Achieving interference between the light that circulates continuously in the loop, that is, by adjusting the resonance frequency of the light in the fiber loop and then measuring the rotation speed of the loop, a resonant fiber optic gyroscope can be manufactured.
Fiber optic gyroscope is an improved type of laser gyroscope. Due to the use of optical fiber (fibers are wound in a loop), the total optical path is greatly increased, so that the optical path difference when rotating is also greatly increased, and the detection accuracy is improved.
The two ends of the optical fiber wound into a multi-turn ring type are connected to a Michelson interferometer. In order to ensure the stable and reliable operation of the system, the optical fiber and the interferometer are usually made into a whole.
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