新型阻抗匹配网络在双路宽光谱AOTF成像技术中的应用

The Application of a New Broadband Matching Network Used in the Dual-track Wide Spectrum AOTF Imaging Technology

基于双路AOTF的宽光谱成像技术在可见光偏振成像光谱仪中得到应用,其成像质量受AOTF衍射效率、光谱带宽等影响。其核心部件超声换能器阻抗失配时导致驱动功率无法最大限度的传递给换能器,使AOTF光谱衍射效率降低,3 d B光谱带宽变窄,影响光谱图像有用信息的获取。采用压缩回波损耗技术,设计了一种基于LC拓扑结构及组合臂的宽频带、光谱衍射效率高的新型匹配网络。最终测得AOTF的光谱衍射效率最高达94%,光谱带宽小于5 nm,提高了在420 nm～1 150 nm波段范围内的光谱衍射效率及分辨率,实测目标的成像质量得到明显改善。

Wide-spectrum imaging technology based on dual AOTF has been applied in visible-light polarization imaging spectrometer.Its imaging quality is affected by AOTF diffraction efficiency and spectral bandwidth.When the impedance of the ultrasonic transducer of the core component is mismatched,the driving power can not be transmitted to the transducer to the maximum.The diffraction efficiency of the AOTF spectrum is reduced and the bandwidth of the 3 dB spectrum is narrowed,which leads to the acquisition of useful information of the spectral image.A novel matching network based on LC topological structure and combinational arm with high bandwidth and high spectral diffraction efficiency was designed using compressed return loss technique.The final measured AOTF spectral diffraction efficiency of up to 94%,the spectral bandwidth of less than 5 nm,increased in the 420 nm^1 150 nm band spectral diffraction efficiency and resolution range,the measured target imaging quality has been significantly improved.