Photon integrated chip and interference type fiber-optic gyroscope

Abstract

The invention discloses a photonic integrated chip and an interference type fiber-optic gyroscope, and the photonic integrated chip can achieve high-density integration of functions of various photoelectric devices such as a waveguide coupler, a polarizer, a mode filter and a phase modulator on a thin film substrate through a photonic circuit structure. The four ports of the photonic integrated chip are placed on the same side of the chip, so that polarization crosstalk or parasitic phase errors caused by substrate radiation mode light waves formed by an asymmetric mode and polarization filtering are reduced, and the error influence on the performance of the fiber-optic gyroscope system is reduced. According to the interference type fiber-optic gyroscope, optical fibers are respectively placed at four ports of a photonic integrated chip and are respectively connected with a light source, a photoelectric detector and two ports of a fiber-optic ring, so that a light path structure of the interference type fiber-optic gyroscope is formed.

Description

technical field [0001] The invention can be applied to the technical fields of inertial sensing such as optical fiber gyroscopes, and in particular relates to a photonic integrated chip and an interference type optical fiber gyroscope. Background technique [0002] Inertial technology is the core technology for inertial navigation, guidance and control, positioning and orientation, and attitude stabilization of various moving objects. The gyroscope, as the core component of the inertial measurement system, is used to measure the angular displacement and angular velocity of the moving object. Performance plays a key role. The closed-loop interferometric fiber optic gyroscope based on the Sagnac effect has the advantages of no moving parts, large dynamic range, high sensitivity, anti-electromagnetic interference, flexible structure, etc., as well as its strong compatibility with optical communication devices, which can realize mass production. To the rapid development and wid...

AI Technical Summary

Problems solved by technology

[0006] However, the double Y waveguide modulator prepared by the above-mentioned prior art and the interferometric fiber optic gyroscope based on it have the following problems, which will have adverse effects on the volume, sensing accuracy, reliability, and manufacturing cost of the fiber optic gyroscope system:

[0007] First, although the structure of the dual Y-waveguide modulator improves the integration of device functions, because the light wave will form light splitting at the first Y branch, a part of the light wave will form an asymmetric mode radiation and enter the substrate wafer. A part of the light wave is recoupled into the second Y branch through the reflection of the bottom or side wall of the substrate wafer, forming a parasitic phase error, which affects the accuracy of the fiber optic gyroscope;

[0008] Second, since the Y waveguide used in the fiber optic gyroscope uses a proton exchange waveguide with polarization characteristics, and the interference fiber optic gyroscope often uses a low-polarization light source, part of the light wave energy incident into the Y waveguide will be radiated as The mode exists in the substrate wafer, and the reflection through the bottom or side wall of the substrate wafer will also be recoupled into the output port of the Y-waveguide modulator and exist in the fiber optic gyro system in the form of polarization crosstalk noise, which will affect the accuracy of the fiber optic gyroscope;

[0009] Third, the larger size of the Y-waveguide modulator is one of the main limiting factors for the miniaturization of the fiber optic gyroscope. In the prior art, the miniaturization of the Y-waveguide modulator is generally achieved by shortening the length of the curved waveguide. On the one hand, it will lead to an increase in the bending loss of the Y-waveguide modulator, and on the other hand, it will also lead to an increase in the half-wave voltage, which will further lead to an increase in the driving power consumption of the fiber optic gyroscope system and an increase in the difficulty of signal processing

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