What Is a Ring Laser Gyroscope?

Modern gyroscope is an instrument that can accurately determine the position of moving objects. It is a kind of inertial navigation instrument widely used in modern aviation, navigation, aerospace and national defense industry. The development of high technology is of great strategic significance. The traditional inertial gyroscope mainly refers to the mechanical gyroscope. The mechanical gyroscope has high requirements on the technical structure and complex structure, and its accuracy is restricted by many aspects.

Gyroscopes are generally divided into laser gyroscopes, fiber optic gyroscopes, micromechanical gyroscopes, and piezoelectric gyroscopes. These are electronic and can be manufactured with GPS, magnetoresistive chips, and accelerometers into inertial navigation control systems.

Modern fiber-optic gyroscopes include interference gyroscopes and resonant gyroscopes, which are developed according to Segnik's theory. The gist of Segnik's theory is this: When the light beam travels in a circular channel, if the circular channel itself has a rotational speed, then the time required for the light to travel in the direction of the channel's rotation is faster than that along the channel. It takes more time to move in the opposite direction.

That is to say, when the optical loop rotates, the optical path of the optical loop will change with respect to the forward path when the loop is stationary. Using this change in optical path, if interference is caused between light traveling in different directions to measure the rotation speed of the loop, then an interferometric fiber optic gyroscope can be manufactured. To achieve the interference between the light continuously circulating in the loop, that is, by adjusting the resonant frequency of the light in the fiber loop and measuring the rotation speed of the loop, a resonant fiber optic gyroscope can be manufactured.

From this simple introduction, it can be seen that the interference path gyroscope has a small optical path difference when it implements interference, so the light source it requires can have a larger spectrum width. When a resonant gyroscope implements interference, its The optical path difference is large, so the light source it requires must have good monochromaticity.

Since the 1970s, the development of modern gyroscopes has entered a whole new phase. In 1976, the basic idea of modern fiber optic gyroscope was proposed. After the 1980s, modern fiber optic gyroscope has developed very quickly, and at the same time, laser resonant gyroscope has also developed greatly. Because the fiber optic gyroscope has the advantages of compact structure, high sensitivity, reliable operation, etc., the fiber optic gyroscope has completely replaced the mechanical traditional gyroscope in many fields and has become a key component in modern navigation instruments. In addition to the ring-type laser gyroscope, there is also a modern integrated vibratory gyroscope that is developed simultaneously with the fiber-optic gyroscope. The integrated vibratory gyroscope has a higher degree of integration and a smaller size. It is also an important part of modern gyroscopes. Direction of development.

Gyroscopes are usually installed in addition to determining the east-west, north-south direction, and on vehicles or vehicles above and below, such as airplanes, spacecraft, missiles, satellites, submarines, and so on. It is the main basis for judging the position in aviation, navigation and space navigation systems. This is because under high-speed rotation, the rotation axis of the gyroscope is stably pointing to a fixed direction. After comparing this direction with the aircraft's axis, the correct direction of the aircraft can be accurately obtained. A compass cannot replace a gyroscope because a compass can only determine the direction of a plane. On the other hand, gyroscopes are also more convenient than traditional compasses. Because traditional compasses are oriented using the Earth's magnetic field, they will be disturbed by mineral distribution, such as the influence of iron-containing substances in the fuselage or hull of an aircraft. Due to the difference between the geographic north pole and the geomagnetic north pole, aeronautics and navigation have already used gyroscopes and satellite navigation systems as the main instruments for orientation.

As the core of the inertial navigation system of the aircraft, the inertial devices occupy a very important position in many fields of national defense science and technology and national economy. The laser gyroscope took a long time and a large amount of investment to solve the problem of lock-up. The aircraft navigation-grade instrument was not developed until the early 1980s, and it was quickly applied to aircraft and helicopters, replacing the power-tuned gyroscope and the integral mechanical gyroscope. It has been widely used in the fields of navigation, radar and guidance.