A miniature optical module for multi-channel distributed optical fiber temperature sensing system

Abstract

The invention relates to a miniature optical module for a multi-channel distributed optical fiber temperature sensing system, which differs in that it includes a single-mode to multi-mode collimator, a multi-mode collimator, two Filters, an optical path switching element, two bandpass filters, two TO hermetic packaged avalanche photodiodes APDs with converging functions, and a housing that encapsulates the entire optical device. The single-mode to multi-mode collimation Two wavelength-division multiplexing filters at an angle to the optical axis are arranged in parallel on the transmission optical path of the device, and one said avalanche photodiode APD is arranged on the reflection optical path of each wavelength-division multiplexing filter, and each avalanche Above the photodiode APD, the band-pass filter is arranged, the incident light of the band-pass filter forms an included angle with the optical axis, and the wavelength division multiplexing filter and the multi-mode collimator are provided with a channel for switching the optical path. The optical path switching element. The invention can measure in multiple channels, has high integration, small volume and high reliability.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensing and optical measurement, in particular to a miniature optical module used in a multi-channel distributed optical fiber temperature sensing system. Background technique [0002] Distributed optical fiber temperature sensing technology is one of the key technologies that has developed rapidly in China in recent years. The distributed optical fiber temperature sensing system uses ordinary multimode optical fiber as the sensing carrier, which not only has the advantages of ordinary optical fiber sensors, but also has the ability to sense the temperature field distribution at various points along the optical fiber in real time, which is very suitable for a wide range of Spot temperature measurement applications, such as high-voltage power cables, large generators, transformers, coal, boilers and other temperature measurement occasions. [0003] The basic principle of distributed optical ...

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Problems solved by technology

However, this solution has the following disadvantages: 1) It does not solve the problem of mode matching between the single-mode fiber output by the pulse light source and the multi-mode fiber reflected by the sensor; 2) The coupling position of the second APD (410) is consistent with the The horizontal axis forms an inclined angle, which is not conducive to coupling, but also increases the volume of the entire optical module; 3) Multi-channel measurement cannot be achieved

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