基于波前编码的便携式皮肤检测仪镜头设计

Design of Portable Skin Detector Lens Based on Wavefront Coding

摘要: 针对便携式皮肤检测仪镜头无法在一定距离范围内清晰对焦成像的问题，文章提出将波前编码技术引入皮肤检测仪光学系统进行景深延拓。首先根据相关系统参数使用Code V软件设计一款小型便携式皮肤检测仪镜头，使其在焦平面上成像质量良好。然后结合系统的PSF和MTF设置相位板参数优化的评价函数和限制条件，采用Code V和Python的COM组件接口进行数据交互，在Python中编写遗传算法对相位板的面型参数进行迭代优化，筛选出最佳的相位板调制系数。同时引入集成波前编码系统，将相位调制参数集成到原系统的某个光学元件表面，这样不需要给相位板预留空间位置，使得整个光学系统更加灵活紧凑。最后在仿真实验中，使用Lucy-Richardson算法还原模糊的中间图像，以检验系统在景深扩展方面的性能，仿真结果显示：与原系统相比，波前编码系统的景深增加了至少28倍，还原后图像的峰值信噪比最高可达28.38 dB。

Abstract: To address the problem of the portable skin detector lens being unable to achieve clear focus within a certain distance range, it is proposed to introduce wavefront coding technology into the optical system of the skin detection device to extend the depth of field. Firstly, a compact portable skin detector lens is designed using the Code V software based on relevant system parameters to ensure good imaging quality at the focal plane. Then, by combining the PSF and MTF of the system, the evaluation functions, and restriction conditions for optimizing the phase plate parameters are set. The Code V software and Python’s COM component interface are used for data exchange, and a genetic algorithm is implemented in Python to iteratively optimize the surface parameters of the phase plate, selecting the optimal phase modulation coefficients. At the same time, an integrated wavefront coding system is introduced to integrate the phase modulation parameters onto the surface of a certain optical element in the original system. This eliminates the need to reserve space for the phase plate, making the entire optical system more flexible and compact. Finally, in the simulation experiment, the Lucy Richardson algorithm is used to restore the blurred intermediate image to test the performance of the system in depth extension. The simulation results show that compared with the original system, the depth of field of the wavefront coding system increases by at least 28 times, and the peak signal-to-noise ratio of the restored image can reach up to 28.38 dB.