分析了La3Ga5SiO14(简称LGS)既可以做成同向声光可调谐滤波器,又可以做成大孔径非同向声光可调谐滤波器。推导出超声波频率f和光波波长λo的调谐关系;计算出滤波器的光谱分辨率R和集光能力δiθ;光入射角iθ与衍射角θd、声入射角θa之间的关系。为LGS声光可调滤波器的实用化设计提供了充分可靠的理论依据。把LGS与TeO2声光可调滤波器的光谱分辨率和集光能力做了比较,认为LGS设计成同向声光可调谐滤波器既简便又实用。 It is analyzed that La3Ga5SiO14 (referred to as LGS) can be made into the same direction acousto-optic tunable filter, and can also be made into a large aperture non-isotropic acousto-optic tunable filter. Derives the tuning relationship between the ultrasonic frequency f and the wavelength λo of the optical wave; calculates the spectral resolution R of the filter and the light gathering capability δiθ; the relationship between the light incident angle iθ and the diffraction angle θd and the acoustic incident angle θa. It provides the sufficient and reliable theoretical basis for the practical design of LGS acousto-optic tunable filter. Comparing the spectral resolution and light collecting ability of LGS with TeO2 acousto-optic tunable filter, it is considered that LGS is designed as a coherent acousto-optic tunable filter which is both simple and practical.