近红外偏振干涉光谱仪的光学系统设计

Optical System Design of Near Infrared Spectroscopy Based on Polarized Interference

提出一种基于偏振干涉的单光路近红外光谱仪光学系统.针对光纤耦合卤钨灯光源,设计离轴抛物面镜准直和会聚光学系统.氦氖激光作为采集控制光源,用冷光镜与近红外光束实现分合.采用正交放置的格兰-汤普逊棱镜为起偏和检偏器,设置补偿晶体和扫描光楔完成偏振干涉的相位补偿.近红外光偏振干涉光谱仪光学系统的光谱范围为800~1 700nm,理论光谱分辨率优于8cm^-1,通光口径Φ10.4mm.质量评价表明,全视场点列图均方根半径值约为1.7μm,垂轴色差小于0.2μm,全视场范围内几何包围圆Φ14μm之内能量达到100%.

Based on polarized interference principle, an optical system of near infrared spectroscopy with single optical path was proposed. For the tungsten halogen source coupled with optical fiber, the collimated and convergent systems using 90° off-axial parabolic mirror were designed. He-ne laser as source for sampling control was introduced, and the beams are combined and split with near infrared by a cold mirror. Two perpendicular Glan-thompson prisms are introduced as polarizers, within the compensated crystal and scanning wedge are set as optical phase compensator of the polarization interference. A near infrared polarization interference-based optical system was designed, whose wavelength band is from 800 nm to 1700 nm, theoretical spectrum resolution is better than 8 cm-1 , and clear aperture is Ф10.4 mm. The results of quality evaluation show that the root mean square radius at marginal field of view according to the spot diagram is about 1.7 μm, the lateral chromatic aberration is 0.2μm, and the geometric encircled energy at all the field of view has reached to 100% within a diameter of Ф14 μm.