Highly Directional Semiconductor Laser Created at Harvard

We often think of lasers as sharp, highly focused beams of light, but the truth is that most of the time lasers have high divergences, spreading light into beams similar to those produced by flashlights. This is especially true for semiconductor lasers, such as those used in building CD-ROM devices and in fiber-optics, which usually require complex optic systems in order to bring the beam into a usable form.