Braze welding packaging and manufacturing method for making fiber bragg grating into double-peak grating

Abstract

The invention discloses a braze welding packaging and manufacturing method for making a fiber bragg grating into a double-peak grating. The braze welding packaging and manufacturing method comprises the following steps of: taking one fiber bragg grating at will, wherein a grating forming part of the grating is a naked grating, and the surface is free from any protective layer; carrying out surface metallization to the fiber bragg grating, wherein the metallization thickness is 30-50 micrometers; corroding a half of a surface metallization layer along the grating length direction by nitric acid, and reserving the other half; putting the grating part with the metallization layer into an aluminum alloy tube; guaranteeing that the gap is between 30 and 50 micrometers; putting low-temperature brazing paste between the grating and the inner wall of the aluminum alloy tube, wherein the brazing paste can be medium-and-low-temperature Sn base or Al base brazing paste; putting the aluminum alloy tube and the built-in grating into a temperature-control furnace; heating to be 30-50DEG C above a brazing material melting point; and keeping warm for 20-50 seconds, thus obtaining a double-wavelength fiber bragg grating after slowly cooling. The braze welding packaging and manufacturing method disclosed by the invention has a simple technical process, and the obtained double-peak grating can be used for the field that a plurality of physical quantities are simultaneously subjected to discriminating measurement.

Description

technical field [0001] The invention relates to a brazing encapsulation manufacturing method for making a fiber Bragg grating into a bimodal grating. Background technique [0002] Fiber Bragg grating uses the photosensitivity of the fiber material to write the coherent field pattern of the incident light into the fiber core by ultraviolet light exposure, and produces a periodic change in the refractive index along the axis of the fiber core in the fiber core, thereby forming a spatial phase The function of the grating is essentially to form a narrow-band (transmission or reflection) filter or mirror in the fiber core. When a beam of wide-spectrum light passes through a fiber Bragg grating, the wavelengths that meet the Bragg conditions of the fiber Bragg grating will be reflected, and the rest of the wavelengths will continue to transmit through the fiber Bragg grating. Fiber Bragg gratings can be used to measure physical quantities such as temperature, pressure, and strain...

AI Technical Summary

Problems solved by technology

However, since the fiber Bragg grating itself is sensitive to both temperature and strain, it is difficult to distinguish the temperature and stress (strain) of the structure to be measured at the same time. This is a difficult task for a single-peak fiber Bragg grating. The Bragg grating (single peak) is made into a double peak grating with a similar central wavelength. The double peak grating can be used in the fields of filtering, temperature and pressure simultaneous measurement, etc. At present, there is no method of brazing packaging to make the fiber Bragg grating at home and abroad. bimodal grating method

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