f-theta透镜作为激光扫描系统中必不可少的部件, 对系统工作面尺寸、测量速度、测量精度等起着决定性的作用。为改变以往f-theta透镜扫描范围小、工作波长单一等不足, 设计出了一种工作于486 nm~656 nm波段的广角f-theta透镜。通过初级像差分析, 确定系统的初级结构参数, 利用光学材料的不同色散性能分配合理的光焦度来进行色差校正。设计结果表明: f-theta镜头像散值在像差容限范围内满足平像场要求, f-theta镜头系统最大色差为3 μm, 线性畸变误差值不超过0.015%, 光能利用率接近90%, 聚焦性能接近衍射极限, 满足多工作波长、高精度激光打标机的实际需求。

The f-theta lens is an important essential component in laser scanning systems that plays a decisive role in working surface, measuring speed and measurement accuracy,etc. A wide-angle f-theta lens operating at 486 nm ~ 656 nm is designed to change the range of small f-theta lens scanning range and single operating wavelength.Through the primary aberration analysis, the primary structure parameters of the system are determined, and the chromatic aberration correction is carried out by using the optical power distribution with different dispersion properties. The final design result shows that the lateral color is less than 3 μm, the calibrated f-Theta distortions are all less than 0.015% and the energy utilization rate is nearly 90%,which means that the focusing performances are close to the diffraction-limited. The system meets the requirements of high-precision laser marking systems with different waves.