双波段长后工作距连续变焦光学系统设计

Design of Dual-Band Optical System with Long Back Working Distance and Continuous Zoom

为满足目前生物医学活体成像研究领域对多波段荧光成像的迫切需求,提出并设计了一种可见光(486~656 nm)、近红外(900~1700 nm)双波段长后工作距有限远变焦光学系统。针对双波段、长后工作距变焦系统带来的色差变化范围大、组分光焦度选择受限等技术难题,通过理论分析,选择了适合该双波段系统的变焦结构,计算得到了系统4组变焦结构的初始光焦度,并利用理想近轴面验证变焦方案初始结构的可行性,在此基础上对系统每一组元进行独立像差设计,共光路部分兼顾双波段像差进行优化,后组采用分光棱镜对两个波段分光,并针对双波段设计不同的后固定组以校正系统残余像差,同时实现长后工作距下的双波段成像。系统公差特性良好,变焦曲线平滑无拐点,变倍过程中像面稳定,成像质量良好。

A dual-band optical system with a long back working distance and limited far zoom is proposed and designed for visible light(486‒656 nm)and near-infrared(900‒1700 nm)to satisfy the urgent demand for multiband fluorescence imaging in biomedicine imaging research.A zoom structure suitable for the dual-band system is adopted to address technical problems such as the broad range of chromatic aberration variation and limited selection of component optical power caused by the dualband long-back-working distance zoom system.The initial optical powers of four groups of zoom structures of the system are calculated.The feasibility of the initial structure of the zoom scheme is verified using the ideal paraxial plane.The independent aberration design is performed for each group element of the system.In the common optical path part,dual-band aberration is optimized.The rear group uses a splitter prism to separate the two bands.Different rear fixed groups are designed for dual bands to correct the residual aberration of the system,and dual-band imaging under the long back working distance is realized.The system exhibits good tolerance characteristics,the zoom curve is smooth without an inflection point,the image plane is stable during the zooming process,and the imaging quality is excellent.