Tunable FP optical filter based on lithium niobate film

Abstract

The invention belongs to the technical field of thin-film narrow-band filters, and particularly relates to a tunable FP optical filter based on a lithium niobate film. The tunable FP optical filter comprises a substrate, a first metal layer, an electro-optic tunable lithium niobate film light transmission layer and a second metal layer. By controlling the voltage between the first metal layer andthe second metal layer, the central wavelength of the tunable FP optical filter of the present invention of a tunable filter can be adjusted. The lithium niobate film is used as the cavity material ofa half-wave resonant cavity in an optical interference film, has a wide light transmission window, a high electro-optical coefficient and good temperature stability, can greatly reduce the optical loss of the narrow-band tunable filter, and realizes the tunable central wavelength. According to the invention, the problems of large optical loss, low tuning speed, temperature sensitivity and the like of an existing MEMS thermo-optical tuned filter can be effectively improved, and the MEMS thermo-optical tuned filter has a good application prospect in the field of optical sensing.

Description

technical field [0001] The invention belongs to the technical field of thin-film narrow-band filters, and in particular relates to a tunable FP filter based on a lithium niobate thin film. Background technique [0002] Optical filters are made by adding special fuels to plastic or glass substrates or evaporating optical films on their surfaces to attenuate certain light bands in the light waves or to precisely select small-range bands of light waves to pass through, while reflecting other light waves. Bands that are not expected to pass. By changing the structure of the filter and the optical parameters of the film layer, various spectral characteristics can be obtained, so that the filter can control, adjust and change the transmission, reflection, polarization or phase state of light waves, and is widely used in spectral cameras. [0003] In order to realize the detection of various spectra, the traditional multi-band imaging device needs to use different filters, and the...

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is: how to provide a tunable filter structure in view of the above defects or improvement needs of the prior art, and it is required that it can effectively improve the optical loss existing in the existing MEMS type and thermo-optic tunable filters Large, slow tuning speed, temperature sensitivity, poor stability and other problems, it has a good application prospect in the field of spectral imaging

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