Mao Shan, Nie Huaile, Lai Tao, Xie Na
Key Laboratory of Light Field Manipulation and Information Acquisition, Ministry of Industry and Information Technology, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710129, China.
Science and Technology on Electro-Optical Information Security Control Laboratory, Tianjin 300308, China.
Sensors (Basel). 2022 Jul 15;22(14):5291. doi: 10.3390/s22145291.
The special dispersion and temperature characteristics of diffractive optical element (DOE) make them widely used in optical systems that require both athermalization and achromatic aberrations designs. The multi-layer DOE (MLDOE) can improve the diffraction efficiency of the overall broad waveband, but its diffraction efficiency decreases with changes in ambient temperature. When the ambient temperature changes, the micro-structure heights of MLDOE and the refractive index of the substrate materials change, ultimately affecting its diffraction efficiency, and, further, the optical transform function (OTF). In this paper, the influence of ambient temperature on the diffraction efficiency of MLDOE in a dual-infrared waveband is proposed and discussed, the diffraction efficiency of MLDOE caused by ambient temperature is derived, and a computational imaging method that combines optical design and image restoration is proposed. Finally, a dual-infrared waveband infrared optical system with athermalization and achromatic aberrations corrected based on computational imaging method is designed. Results show that this method can effectively reduce the diffraction efficiency of MLDOE by ambient temperature and improve the imaging quality of hybrid optical systems.
衍射光学元件（DOE）的特殊色散和温度特性使其广泛应用于需要消热差和消色差设计的光学系统中。多层衍射光学元件（MLDOE）可以提高整个宽波段的衍射效率，但其衍射效率会随环境温度的变化而降低。当环境温度变化时，MLDOE的微结构高度和基底材料的折射率会发生变化，最终影响其衍射效率，进而影响光学传递函数（OTF）。本文提出并讨论了环境温度对双红外波段MLDOE衍射效率的影响，推导了环境温度引起的MLDOE衍射效率，并提出了一种结合光学设计和图像恢复的计算成像方法。最后，基于计算成像方法设计了一种具有消热差和消色差校正功能的双红外波段红外光学系统。结果表明，该方法可以有效降低环境温度对MLDOE衍射效率的影响，提高混合光学系统的成像质量。
