Small-diameter solid core polarization-maintaining photonic crystal fiber of four-layer structure

Abstract

The invention discloses a small-diameter solid core polarization-maintaining photonic crystal fiber of a four-layer structure and belongs to the technical field of microstructure fibers. The concrete structure refers to that a section is round, and the fiber sequentially comprises a coating layer, a cladding and cladding air pores from outside to inside. The cladding air pores are of a four-layer symmetric structure and are arrayed in a hexagon. The centers of the cladding air pores are concave parts, two large air pores are formed in the centers in the x-axis direction to form shape birefringence of the fiber. The diameter d of each cladding air pore is 3.0-3.8 micrometers; the distance A between every two adjacent cladding air pores is 5.4-6.2 micrometers; the diameter D of each large air pore is 5.5-6.4 micrometers, the duty ratio d/Lambada is 0.55-0.65, and the range of the normalized frequency Lambada/Lambada is 3.5-4. The fiber has the advantages that gyro precision is substantially improved within a certain size limit, the temperature performance of an fiber gyro and the temperature stability of fiber birefringence are improved, and the temperature sensitivity of the fiber gyro is reduced; an fiber mode field diameter is closer to that of a common polarization-maintaining fiber, so the welding loss is smaller; the diameters of the cladding and the coating layer are smaller than those of a current fiber, so gyro miniaturization is facilitated.

Description

technical field [0001] The invention belongs to the technical field of microstructured optical fibers, and in particular relates to a thin-diameter solid-core polarization-maintaining photonic crystal optical fiber with a four-layer structure. Background technique [0002] As a new type of inertial angular velocity sensor that is developing rapidly, fiber optic gyro has its unique technical and performance advantages, such as all-solid-state structure, high reliability, long life; fast start-up speed, short response time; large measurement range and wide dynamic range; Anti-shock, vibration, chemical corrosion resistance; small size, light weight, low cost and suitable for mass production, etc., have been widely used in various fields. The internationally common form of fiber optic gyroscope is to use a set of optical paths to realize the SAGNAC interferometer, and solve the SAGNAC caused by the rotation of the carrier through the interference between the two main wave train...

AI Technical Summary

Problems solved by technology

[0023] The purpose of the present invention is to solve the problem in the prior art that the diameter of the cladding layer and the coating layer is large, which cannot meet the needs of miniaturized gyroscopes, and proposes a thin-diameter solid-core polarization-maintaining photonic crystal fiber with a four-layer structure

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