激光多普勒测振仪中光学天线的优化设计与测试

Optimization design and testing of optical antennas for laser Doppler vibrometers

传统的激光测振仪多使用氦氖激光器,不满足人眼安全条件,在户外容易受到太阳光干扰。其使用的光学天线大多数仅能工作于氦氖激光器的辐射波段,同时存在结构复杂、成本较高、收集效率低、工作距离较短等不足。为了解决以上问题,基于近红外波段透镜组的扩束和聚焦原理,以Zemax作为设计工具,以点列图和波前图为主要分析手段,设计并制作了一款可工作于1550 nm的三片式收发一体光学天线,结构简单,成本低。分析结果显示:在0.3~15.0 m的工作距离范围内均可获得直径小于2 mm的聚焦光斑;测试结果显示其最大收集效率可达到51.6%。同时,将该光学天线应用于自主设计搭建的激光多普勒测振仪中,实现了不同工作距离下的振动测量,有效扩展了激光测振仪的应用范围和应用场景,在机械、航空、建筑、医学、农学等领域有很大的应用潜力。

Traditional laser vibrometers often use helium-neon lasers,which do not meet the safety requirements of the human eye and are susceptible to interference from sunlight.The optical antennas used in these systems mostly operate within the radiation band of helium-neon lasers.However,they suffer from drawbacks such as complex structure,high cost,low collection efficiency,and short working distance.In order to address these issues,a three-piece integrated optical antenna working at 1550 nm was designed and produced based on the beam expanding and focusing principles of the near-infrared wavelength range,with Zemax serving as the design tool and spot diagrams and wavefront maps as primary analysis methods,showing a simple structure and cost-effectiveness.The analysis results show that focused light spots with a diameter less than 2 mm can be obtained within a working distance range of 0.3-15.0 m;the test results indicate a maximum collection efficiency of 51.6%.Integrating this optical antenna into a self-designed laser Doppler vibrometer enabled vibration measurements at different working distances,effectively expanding the application range and scenarios of laser vibrometers.This innovation has significant potential applications in fields such as mechanical engineering,aviation,architecture,medicine,and agriculture.