The optimization of the beam of laser

摘要

Laser diodes are efficient, compact, and inexpensive light sources and are already part of our modern life. However, their use for spectroscopy has been limited due to the intrinsic problem of reliably controling output frequency and power. In application where linewidth, stability or tunable narrow-band frequency output is required, free-running laser diodes are from satisfactory. The problem can be overcome with External-Cavity Diode Lasers (ECDL). The obvious features of my working are the optimization of the spatial mode and the design of the direction of light. We design the optical trace, and having a well result. In the process of the experiment using grating for the modulation of external-cavity and geometry optimization for maintaining the fixed direction of output beam. So when declining the grating for tuning the frequency of laser, you have not the demand of changing the rest part in experiment. In the system, I utilized a feedback to obtain a good precision of the controlling of the temperature and current.