声光可调滤光器的辐照特性研究

Study on Irradiation Characteristics of Acousto-Optic Tunable Filter

该文介绍了声光可调滤光器器件及器件中的关键材料——声光介质氧化碲晶体与换能器铌酸锂晶体的辐照特性。辐照实验采用中子辐照(中子注量1.5×10^(12)n/cm^(2)@1MEV等效电子)和电离辐照(总剂量6×10^(3)Gy(Si))。采用高分辨X线衍射(HRXRD)分析了氧化碲与铌酸锂晶体,分析显示辐照前后两种晶体的X线衍射峰无变化,表明它们的晶格常数无变化,但其摇摆曲线变宽,表明它们吸收的辐照能量使晶体内部应力增大。采用阻抗分析仪测试了辐照前后铌酸锂的机电耦合系数,测试表明辐照使机电耦合系数降低了约1%。采用1064 nm等4种波长的激光测试了声光可调滤光器器件的滤光功能和衍射效率,测试表明滤光功能正常,辐照使衍射效率下降了约2%。因此,辐照对声光可调滤光器影响较小,适合辐照条件下的深空探测。

This paper introduces the irradiation characteristics of the acousto-optic tunable filter device,the key acousto-optic medium tellurium dioxide crystals and the transducer lithium niobate crystals in the device.The radiation experiments included neutron irradiation(neutron fluence of1.5×10^(12)n/cm^(2)@1MEV equivalent electrons)and ionizing radiation(total dose of 6×10^(3)Gy(Si)).High-resolution X-ray diffraction(HRXRD)analysis of tellurium dioxide and lithium niobate crystals before and after irradiation showed no change in their X-ray diffraction peaks,indicating that their lattice constants remained unchanged.However,their rocking curves became wider,indicating that the absorbed radiation energy increased internal stresses within the crystals.An impedance analyzer was used to measure the electromechanical coupling coefficient of lithium niobate before and after irradiation,showing that irradiation reduced the electromechanical coupling coefficient by about 1%.Four different wavelengths of lasers,including 1064nm,were used to test the filtering function and diffraction efficiency of the acousto-optic tunable filter devices.The tests indicated that the filtering function was normal,and irradiation caused about a 2%reduction in diffraction efficiency,suggesting that the impact of irradiation on the acousto-optic tunable filters was minimal,making them suitable for deep space exploration under irradiation conditions.