The majority of existing high-power laser therapeutic instruments employ a single wavelength for a single target; thus, they do not meet the requirements for clinical treatment. Therefore, this study designs an optical system for a dual-wavelength high-power laser therapeutic device with a variable spot size. The waist of the short arm of the optical cavity and the G1G2 parameter (G-parameter equivalent cavity method) is calculated using MATLAB software, the spot size and divergence angle on the lens are calculated using an ABCD matrix, and the distance between the treatment spot at different spot sizes and the transformation lens is calculated in order to design the treatment handpiece. Experiments are conducted to analyze the stability at an output power of 532 nm before beam combination and the power loss after beam combination. The results show that the output power stability of the 532-nm beam varies by less than 2% over 150 min, and the loss of both wavelengths is less than 20%, which meets the clinical requirements of the system. The safety performance can meet the requirements of national general standards for medical electrical safety. The proposed dual-wavelength laser therapy instrument has both visible wave and near-infrared wave characteristics; thus, it can accurately target both superficial vessels and vessels with a larger diameter and deeper position. This therapeutic device has the advantages of simple operation, stable and reliable laser output, high security and strong anti-interference ability, and meets the comprehensive clinical treatment demands of vascular diseases.

中文翻译：

---

用于双波长激光治疗仪的可变光斑尺寸光学系统

大多数现有的高功率激光治疗仪采用单一波长的单一目标；因此，它们不符合临床治疗的要求。因此，本研究设计了一种用于具有可变光斑尺寸的双波长高功率激光治疗仪的光学系统。使用MATLAB软件计算光腔短臂腰部和G1G2参数（G参数等效腔法），使用ABCD矩阵计算镜片上的光斑尺寸和发散角，以及治疗之间的距离不同光斑尺寸的光斑，并计算转换透镜，以设计治疗手机。通过实验分析了合束前532 nm输出功率下的稳定性和合束后的功率损耗。结果表明，532nm光束的输出功率稳定性在150 min内变化小于2%，两个波长的损耗均小于20%，满足系统的临床要求。安全性能可满足国家医用电气安全通用标准的要求。提出的双波长激光治疗仪兼具可见波和近红外波特性；因此，它可以准确地瞄准浅表血管和直径更大、位置更深的血管。该治疗仪操作简单、激光输出稳定可靠、安全性高、抗干扰能力强，满足血管疾病临床综合治疗需求。