Self-developing aspherical chalcogenide-glass microlenses for semiconductor lasers

A principle of self-developing microlenses for semiconductor lasers has been demonstrated using a photosensitive glass, As2S3. The glass film is placed in front of a semiconductor laser, the light from which increases the refractive index and thickness of the film. If its position and thickness are properly selected, the illuminated film operates as an aspherical microlens which can focus an elliptical laser beam to a circular spot.