Optical fiber micro-vibration sensor

Abstract

The invention provides an optical fiber micro-vibration sensor which comprises an optical sense cavity and an optical no-sense cavity, wherein the optical sense cavity is formed by connecting a columnar face collecting barrel and a cavity isolation box at the bottom end of the barrel in a sealing mode, and the optical no-sense cavity is formed by connecting the lower bottom face of the cavity isolation box and a hollow bottom cover in a sealing mode. Two optical fiber couplers and a sense reference wheel are arranged inside the optical sense cavity and on the cavity isolation barrel in a supporting mode. Reference optical fiber is manufactured on the sense reference wheel in a winding mode. Contact sense fiber is manufactured on the outer surface of the columnar face collecting barrel in a winding mode and a waterproof micro-hole is formed in the outer surface of the columnar face collecting barrel. Two ends of the contact sense fiber enter the optical sense cavity through the waterproof micro-hole. No-sense guide optical fiber guided out by the two optical fiber couplers enters the optical no-sense cavity through the cavity isolation box. A stern line supporting frame is arranged inside the optical no-sense cavity and on the cavity isolation box in a supporting mode. Two pieces of the no-sense guide optical fiber is wound around the stern line supporting frame and connected with a transmitting guide optical cable. The transmitting guide optical cable penetrates out of the top end of the columnar face collecting barrel through the cavity isolation box. A Mach-Zehnder sense structure is formed by the contact sense fiber, the reference optical fiber, the two optical fiber couplers and two pieces of the no-sense guide optical fiber.

Description

technical field [0001] The invention belongs to the field of optical fiber sensing, and specifically refers to an optical fiber micro-vibration sensor capable of detecting three-dimensional vibration signals of underground, underwater and air space regions. Background technique [0002] The basic structure of the general-purpose Mach-Zehnder sensor is shown in the accompanying drawings figure 2 As shown, it is mainly composed of a sensing optical waveguide 21, a reference optical waveguide 22, two 1×2 couplers 19, 20 connecting the above two optical waveguides, and two non-inductive guiding optical waveguides for input and output signals. [0003] The deformation and stretching of the optical waveguide produced by the micro-vibration will produce a length difference ΔL between the sensing optical waveguide 21 and the reference optical waveguide 22, when the single-mode laser with an extremely narrow bandwidth reaches the 1×2 coupler from the 1×2 coupler 19 At 20 o'clock, th...

AI Technical Summary

Problems solved by technology

[0010] However, on the one hand, ordinary Mach-Zehnder sensors are only suitable for inductive contact or vibration signals close to the vibration source, and cannot respond or respond extremely weakly to vibration sources that are underground, underwater, or in the space of the gas, or to vibration sources that are far away; On the other hand, in actual use, the sensing optical waveguide 21 and the reference optical waveguide 22 are often in the same physical environment, and vibration interference causes the optical signals in the two optical waveguides to change simultaneously, resulting in uncontrollable light intensity of the synthesized light, making it difficult to pass Subsequent data processing and analysis to obtain the nature and intensity of the vibration source

Images