MEMS (micro-electromechanical system) mechanism based adjustable filter

Abstract

The invention relates to an MEMS (micro-electromechanical system) mechanism based adjustable filter which comprises a base. An MEMS chip is mounted above the base, at least two pieces of zero-inflatedglass identical in thickness are mounted on the outer periphery of the MEMS chip, and a partial reflection mirror A is mounted above the zero-inflated glass. The MEMS chip comprises a chip substratewith a middle hole, an electrification electrode is formed on the chip substrate, cantilever beam structures are arranged above the chip substrate, and vertical telescopic movement of cantilever beamscan be realized under voltage or current drive. Mirror carrier is fixedly mounted at tops of the cantilever beams, a partial reflection mirror B is mounted above the mirror carrier, the weight of thepartial reflection mirror B is smaller than driving force of the cantilever beams, the partial reflection mirror B is parallel to the partial reflection mirror A, the upper surface of the partial reflection mirror A is coated with an antireflection film while the lower surface is coated with a partial reflection film, the upper surface of the partial reflection mirror B is coated with a partial reflection film while the lower surface is coated with an antireflection film, and a thermistor is mounted on the base. The adjustable filter is accurate in tuning and quick in response.

Description

technical field [0001] The invention relates to the field of optical fiber communication and optical fiber sensing, in particular to an adjustable filter based on MEMS mechanism. Background technique [0002] Tunable filters (TOF) can be widely used in the fields of optical fiber communication, optical fiber sensing, and spectral analysis because they can change the position of their transmitted wavelengths. The physical principles of different tunable filters are generally similar. Interference forms a filter band, and then tunes these filter bands by changing some physical parameters. The more representative adjustable filters are based on the principle of volume diffraction grating, based on the principle of Bragg grating, based on the principle of dielectric film filtering, and Based on the principle of F-P cavity filtering. The tunable filter based on the principle of F-P cavity filtering is widely used due to its small size, high contrast of the filter band, and high ...

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Problems solved by technology

[0004] One is to use a wedge-shaped F-P cavity to achieve tunable filtering effects, such as the wedge-shaped F-P tunable filter mentioned in the patent WO2003 / 077386 "Gradient Film Wedge Interference Filter and Method for Laser Tuning", by changing the incident light into the wedge The position of the F-P filter can change the optical path of the resonator to achieve the effect of tuning the projected wavelength, but the process is difficult, the coupling insertion loss is large, and the cost is high

[0005] The other is to use heating to change the refractive index of the F-P filter medium to tune the wavelength. For example, in the patent US7295582B2 "Thermo-optic tunable laser apparatus", it is mentioned that the transmission peak of the F-P filter is changed by using the thermo-optic effect, specifically through the The F-P filter performs temperature control to change the refractive index of its medium, so as to achieve the purpose of changing the effective optical path to tune the wavelength; however, the response speed of this tuning solution through temperature control is relatively slow (generally about 2 seconds), and cannot be used in some Applications requiring fast tuning

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