Adjustable optical filter

Abstract

This invention discloses an adjustable optics filter, which comprises signal source input device, adjustable optics filter device and filter signal output device. The said signal input device comprises light signal with certain bandwidth and light source; the said filter device comprises optics filter device sealed shell, light thermal displacement device, and fiber Brag grating. The said filter signal output device comprises fiber connection device, signal receiving and process device. It controls the light intensity of the source through the controllable logic circuit system in the said light thermal displacement device to make the light thermal absorption material bent to stretch the Brag grating to control the signal output.

Description

【Technical field】 [0001] The invention is an adjustable optical filter, which mainly utilizes photothermal technology and optical fiber Bragg grating filtering principle, combined with logic circuit control to realize adjustable optical filtering. 【Background technique】 [0002] At present, there are many methods to use the reflective properties of Bragg gratings for optical filtering, usually by stretching or longitudinally compressing the part of the optical fiber containing the grating. These methods include the temperature change to make the support with the grating expand; the fiber grating is stretched by the electromagnetic effect; Stress tuning, in these methods, it is easier to stretch than compress the fiber, but the implementation of compression can achieve a larger tuning range, and the compressive strength is much greater than the tensile strength. But how to solve the problem of not causing fiber bending when stretching and compressing Bragg gratings is the ke...

AI Technical Summary

Problems solved by technology

[0003] There is also an arrayed waveguide grating filter based on the acousto-optic effect. However, because the arrayed waveguide grating cannot directly adjust the wavelength of light, it has the disadvantages of high loss and low adjustment speed.

There is also a Mach-Zehnder interferometer, which is also a filter based on the acousto-optic effect. However, this type of interferometer is difficult to manufacture because it requires four reflective surfaces parallel to each other.

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