Method and device for testing diffraction performance of self-referential acousto-optic tunable filter

Abstract

The invention discloses a method and a device for testing diffraction performance of a self-reference acousto-optic tunable filter. The device comprises a wave length tunable laser, a neutral-density filter, a Glan prism, a two-dimensional electric rotary platform and an energy meter and is used for testing performance including diffraction efficiency of the acousto-optic tunable filter. The method is based on crystal properties of the AOTF, self reference is achieved by means of zero-grade light and diffraction light generated after driving, with combination of the method of alternative testing performed by probes of the energy meter, influence on measurement accuracy caused by instability of optical energy and inconsistent response of the probes of the energy meter can be eliminated effectively, an optical path is simple, the method is easy to operate, and the wide-band high-accuracy performance test can be achieved.

Description

Technical field: [0001] The present invention relates to optical measurement technology, specifically a method and device for testing the diffraction performance of an acousto-optic tunable filter that utilizes the characteristics of the acousto-optic device itself to realize the light energy reference, and is used for diffraction such as the diffraction efficiency of the acousto-optic tunable filter. Performance testing. Background technique: [0002] Acousto-optic tunable filter (AOTF) is a narrow-band tunable filter, which is a spectroscopic device made according to the principle of acousto-optic interaction. Wavelength scanning is achieved by changing the frequency-selective splitting wavelength of the RF drive applied to the crystal. At present, this technology has been widely used in non-imaging and imaging spectroscopy instruments. [0003] AOTF's spectroscopic principle: as attached figure 1 As shown, when a beam of polychromatic light passes through a high-freque...

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Problems solved by technology

However, this method also has its limitations, mainly as follows: 1) It is necessary to switch the beam splitter suitable for different spectral bands when testing a wide spectrum, and at the same time, to ensure the test accuracy, it is necessary to test the wavelength-beam splitting curve of the beam splitter, which is time-consuming and laborious ;2) After testing one level (such as +1 level) of the ±1 level of the AOTF device, an additional installation clamp is required for the other level (such as -1 level), and the optical path must be readjusted, which is convenient 3) The base vector deviation and the performance stability of the beam splitter itself will affect the test accuracy

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