1.Key Laboratory of Space Active Opto-Electronics Technology， Shanghai Institute of Technical Physics， Chinese Academy of Sciences， Shanghai 200083， China;2.University of Chinese Academy of Sciences， Beijing 1000496， China
Supported by the National Natural Science Foundation of China （61605231）
Acousto-Optic Tunable Filter （AOTF） based spectroscopy instruments have been widely applied in biomedical， agricultural， aerospace， and other fields. However， the conventional AOTF spectrometers struggle to achieve increased system luminous flux while maintaining spectral resolution and reducing the number of samples. To address the above problems， this paper proposes an AOTF spectral measurement method based on the compressed sensing （CS） theory. Sparse randomly coded composite optical signal modulation in the spectral domain using the multi-frequency acousto-optic diffraction of AOTF. A modulated composite optical signal is obtained in the spectral domain and recorded sequentially using a single-element detector or a focal-plane detector array. The original spectrum or spectral image data cube is then obtained by using compressed sensing reconstruction algorithms. In order to verify the effectiveness of the present method， we constructed a sensing matrix using the actual measured AOTF spectral response bandwidth data and simulated the effect of compressed sampling and target data reconstruction with the spreading spectrum as the recovery target. The simulation results show that the method can reconstruct the spectral data of 512 wavelength points with 202 compressed samples， and the spectral data sampling rate and compression ratio is 0.39. Under this sampling rate， the method can recover the spectral curve with high accuracy， and the PSNR index reaches 41.75 dB， and the SAM and GSAM indexes are 0.9998 and 0.9754. With the simultaneous multi-frequency drive， the system optical throughput is improved by a factor of 5 on average. Compared with the traditional wavelength-by-wavelength point scan sampling method， this method can reduce the total number of samples and improve the luminous flux of the system while maintaining the original spectral resolution， and also compressing the spectral data， which is of great importance in the fields of weak signal detection， rapid identification of substances， and spectral data transmission and storage.
JI Zhong-Peng, GUI Yu-Hua, LI Jin-Ning, TAN Yong-Jian, YANG Qiu-Jie, WANG Jian-Yu, HE Zhi-Ping. An acousto-optic tunable filter spectral measurement method based on compressed sensing[J]. Journal of Infrared and Millimeter Waves,2023,42(1):111~121Copy