Calibration of Acousto-Optic Interaction Geometry Based on the Analysis of AOTF Angular Performance

Abstract

Acousto-optic interaction geometry determines the spectral and spatial response of an acousto-optic tunable filter (AOTF). The precise calibration of the acousto-optic interaction geometry of the device is a necessary process before designing and optimizing optical systems. In this paper, we develop a novel calibration method based on the polar angular performance of an AOTF. A commercial AOTF device with unknown geometry parameters was experimentally calibrated. The experimental results show high precision, in some cases falling within 0.01°. In addition, we analyzed the parameter sensitivity and Monte Carlo tolerance of the calibration method. The results of the parameter sensitivity analysis show that the principal refractive index has a large influence on the calibration results, while other factors have little influence. The results of the Monte Carlo tolerance analysis show that the probability of the results falling 0.1° using this method is greater than 99.7%. This work provides an accurate and easy-to-perform method for AOTF crystal calibration and can contribute to the characteristic analysis of AOTFs and the optical design of spectral imaging systems.

Analysis of Phase Mismatch for Mercurous Bromide-Based Non-Collinear AOTF Design in Spectral Imaging Applications

“…The variations in spectral bandwidth with light wavelength, incident angle, and acoustic angle were analyzed and experimentally verified in the YOZ plane, where the incident angle in the XOZ plane is zero [28]. A frequency bandwidth caused by phase mismatch has also been observed in the YOZ plane [32]. The concept of increasing the separation angle to enlarge the angular aperture of the AOTF to increase optical throughput was proposed [33].…”

Polarization-Multiplexed High-Throughput AOTF-Based Spectral Imaging System

“…This demonstrates that spectral modulation of the AOTF device can be realized using the optimization strategy, making it suitable for polarization multiplexing applications. In addition, our previous work has revealed the consistent response of the incident light at a torsion angle of 2.19° [ 31 ].…”

“…The first device (the 1st AOTF) has optimized crystal geometry parameters of , , and (the 1st AOTF) for non-polarization applications [ 29 , 30 ]. The second device (the 2nd AOTF) is used in the experiments and closes to the parallel tangent principle for e-light input application, with crystal geometry parameters of , , and [ 31 ]. As shown in Figure 5 b,d, the optimized of the 1st AOTF device is 66.81 mm, and the minimum is less than 1.0 μm.…”