环境温度变化对双波段谐衍射光学元件衍射效率的影响

基于二元光学元件的位相延迟表达式,推导出谐衍射光学元件随环境温度影响的位相延迟表达式、衍射效率表达式和带宽积分平均衍射效率表达式.定性分析了谐衍射光学元件衍射效率和带宽积分平均衍射效率与环境温度变化的关系.从理论上解释了谐衍射光学元件的特性,确定了谐衍射光学元件衍射波峰随环境温度变化的现象与变化规律.分析表明:在双波红外范围内,谐衍射光学元件的谐波长随环境温度升高向长波方向漂移,随环境温度降低向短波方向漂移.环境温度变化对谐衍射光学元件衍射效率和带宽积分平均衍射效率的影响较大.因此谐衍射光学元件只能应用于波段较窄、温度变化范围较小的折衍射混合成像光学系统中.

Relationship between diffraction efficiency and environment temperature change for double wavebands for harmonic diffractive optics

Based on the phase delay expression of binary optical element,the diffraction efficiency and polychromatic integral diffraction efficiency expression of harmonic diffractive optical ele-ments are deduced with the environment temperature change.The relationship between diffrac-tion efficiency as well as polychromatic integral diffraction efficiency expression versus environ-ment temperature are analyzed qualitatively.The characteristic harmonic diffractive optical ele-ments are explained theoretically and rules on phenomenon of diffraction wave change with envi-ronment temperature are simulated.Analysis shows that within the scope of the double wave in-frared wavelengths,harmonic wavelength drifts towards long wavelength with the increase of temperature and drift towards short wavelength with decrease of temperature for harmonic dif-fractive optical elements.Polychromatic integral diffraction efficiency is greatly influenced by temperature change.Harmonic diffractive optics can be applied for narrow wavebands of hybrid optical system.