Study on spectral transfer function based on dual AOTF acousto-optic crystal

The acoustic-optic tunable filter(AOTF)-based imaging spectrometer is a new type of detection instrument that integrates image, spectrum and polarization information. The spectral transfer function of the instrument is an important indicator to measure the performance of the instrument. This paper first introduces the working principle of single AOTF-type and dual AOTF-type imaging spectrometer. Then by using the optical domain spectral transmission function, the single and dual AOTF spectral transfer functions expressed by wave number are derived, and in the working band of 400 nm~900 nm, the single and dual AOTF-type spectral transfer functions are calculated and compared.Moreover, the factors affecting the dual AOTF-type spectral transfer function are simulated and analyzed. Finally, the selection of instrument parameters are analyzed and discussed. The results show that with the parameters of the incident light polar angle of 30°and the acousto-optic interaction length of 5 mm, when the wavelengths of the working centers of the dual AOTF imaging spectrometers are equal, the spectral transfer function is improved by 68% compared to the single AOTF imaging spectrometer at the same working center wavelength; when the working center wavelengths are not equal, the dual AOTF-type spectral transfer function is not absolutely superior to the single AOTF type, and there is a critical value.