Tunable optical filter based on MEMS (micro electro mechanical system) technology

Abstract

The invention discloses a tunable optical filter based on an MEMS (micro electro mechanical system) technology. The tunable optical filter comprises an input collimator, a reflector, a focusing lens, a collimation lens, a light splitting element, a reflector and an output collimator which are arranged along a light path, wherein the reflector is rotatable; the light splitting element is a diffraction grating; and the wavelength selection is realized by changing the incidence angle of the diffraction grating through the rotatable reflector. The rotatable reflector is a rotatable MEMS reflectoror a reflector with the same functions as the rotatable MEMS reflector. Through the invention, the angle adjustment characteristic of the MEMS reflector is effectively used to change the incidence angle of the diffraction grating so as to realize the wavelength tuning function; and moreover, small size of the diffraction grating is guaranteed, the tunable optical filter is easy to implement and integrate and suitable for batch production, the elements are few and simple, the cost is saved, the structure is compact and the volume is small.

Description

Technical field [0001] The invention relates to a tunable optical filter. In particular, it relates to a tunable optical filter based on MEMS technology, which is widely used in the field of optoelectronics, spectroscopic spectroscopy and sensing. Background technique [0002] With the rapid development of Dense Wavelength Division Multiplexing (DWDM) systems, people’s requirements for system flexibility are gradually increasing. The tunable optical filter has the function of flexibly selecting the required wavelength, which brings to the optical communication system For convenience, it has been widely used. [0003] The tunable optical filter based on MEMS technology is a small size, simple structure and stable performance filter. Traditional diffraction gratings are relatively large, and are rarely used in optical fiber communication systems. With the continuous development of grating technology and the gradual improvement in fineness, the performance of diffraction gratings h...

AI Technical Summary

Problems solved by technology

Disadvantages of this structure: the incident light of different angles reflected by the rotatable mirror becomes parallel light after passing through the focusing lens. The rotation of the grating cannot achieve the purpose of changing the incident angle of the grating

Disadvantages of this structure: the beam conversion lens group is placed behind the grating, which is easy to decenter, the optical path is relatively sensitive, and the structure is not compact

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