2004 年 30 巻 2 号 p. 82-86
The wave-front distortion of the output beam of a single-mode laser diode (LD) with a collimator lens has been measured and corrected so as to provide a very precise focal spot. A 0.1 W LD at 940 nm wavelength was combined with a specially designed collimator lens, and the wave-front error was about 1λ. This wave-front error was corrected by the laser ablative shaping (LAS) method using ArF excimer laser. The final wave-front error of an output beam was better than λ/4. This output beam was focused on to the plastic plate to make a precise marking for production tracing.