An optical wavelength division multiplexer bandwidth selection device

Abstract

The embodiment of the invention discloses an optical wavelength division multiplexer bandwidth selection device, including: a laser, a narrowband filter, an optical isolator, a broadband coupler, a spectrometer, and a temperature measuring fiber; the laser is used to emit pulsed light, and the pulse The light enters the optical isolator after being filtered by the narrowband filter, enters the broadband coupler from the first port of the broadband coupler after passing through the optical isolator, and enters the temperature measurement after outputting from the third port of the broadband coupler An optical fiber, in which a spontaneous Raman scattering effect occurs in the temperature measuring optical fiber to generate Stolaks light and anti-Stolaks light transmitted backwards, the Stolaks light and the anti-Stolaks light are both The light beam enters the spectrometer through the second port of the broadband coupler, and the spectrometer is used to measure the central wavelength and bandwidth of the back Raman scattered light of the received optical signal. The bandwidth range of pulsed light with different wavelengths can be accurately obtained to select an optical wavelength division multiplexer with a suitable bandwidth.

Description

technical field [0001] The invention relates to the technical field of waveguide media, in particular to an optical wavelength division multiplexer bandwidth selection device. Background technique [0002] The distributed optical fiber temperature sensor uses ordinary optical fiber as the sensitive medium and transmission medium, which has the characteristics of electrical insulation, anti-electromagnetic interference, intrinsic safety, corrosion resistance, small size, light weight, and bendable, etc., and can realize long-distance measurement and monitoring. With the advantages of wide measurement range, high spatial resolution and measurement accuracy, it can be widely used in temperature monitoring of oil and gas pipelines, power cables, spacecraft structural health, metallurgy and chemical industry, subway tunnels, large buildings and other fields. [0003] The signal light in the distributed optical fiber temperature sensor is very weak, and the noise of any device in ...

AI Technical Summary

Problems solved by technology

[0006] However, there are generally two kinds of bandwidths of Raman WDM products at present, one is the bandwidth of ±10nm, and the other is the bandwidth of greater than ±45nm, and these two bandwidths are also randomly produced, and neither the manufacturer nor the supplier has any specific requirements for this. Two bandwidths are screened and controlled

However, through a large number of experiments, it is found that if the distributed optical fiber temperature sensor system uses WDM with a bandwidth of ±10nm, the useful signal of the system is filtered out, and the signal-to-noise ratio of the system is poor; and if the distributed optical fiber temperature sensor system uses a bandwidth greater than For ±45nm WDM, unwanted stray light in the system enters the photoelectric conversion module, especially for short-wavelength ports in WDM, because of the wide bandwidth, useless long-wavelength light will also enter the photoelectric conversion module through this port, while long-wavelength light In particular, the optical power close to 1550nm is relatively large, which will easily lead to the saturation of the photoelectric conversion module, and the amplification of useful signal light will be limited; moreover, the useful light is mixed with useless light, which will cause unfavorable factors for the demodulation of the system. Affects the accuracy and precision of demodulation

Images