准直LED光斑定位系统设计

针对准直激光在长期工作过程中很难克服的漂移问题，设计了一套准直发光二极管（LED）光斑定位系统。该系统将LED光源发出的光经透镜汇聚进光纤，再经过准直器准直输出，用CCD探测光斑图像，采用多圆拟合法定位光斑位置。将系统与定制的半导体激光器（LD）准直定位系统进行了长期稳定性对比实验。结果表明，所设计的准直的LED光斑定位系统光斑位置漂移量更小，稳定性更高，可以作为高精密光学测量的定位基准光源。

Design of a collimated LED spot location system

The collimated laser diode （LD） is often used as the benchmark in the optical measuring system. As it is difficult to overcome the drift in a long-term process,we design a collimated LED spot location system. The light from the LED is converged by the lens and coupled into the fiber,then comes out from the collimator. The spot image is captured by the CCD camera and the position of the spot is located by the multi-circle fitting algorithms. Comparison test has been taken between the designed system and the tailor-made collimated LD light source location system in long-term. The result shows that the collimated LED spot location system drifts much less than LD system. It is more stable and can be used as the benchmark in the high-precision optica/measurement.