Question: How does the laser fit in such a small chip?

Padraic Morrissey answered on 2 Feb 2015:

When people think of lasers they usually picture huge machines and big laser beams. These machines exists but they are mainly used for cutting metal and welding parts together. Most of the lasers scientists and engineers work with are actually really small…but they thing is, even though they are small they can emit a lot of power! They are really efficient, which means that a little bit of electricity can power a strong laser.

Did you know that DVD players work using a lasers? There is a tiny laser in the optical drive that shines light onto the disk. How the light is reflected off the disk allows you to read the information from it.

The lasers I work with are even smaller than the lasers used in DVD players! Because they are so small we can fit loads of them onto a single chip. The problem with making them this size is that they are very easy to lose though…if they fall on the ground it’s almost impossible to find them again!