Superluminescent diode

A superluminescent diode (or SLD) is a special kind of light-emitting device that makes light brighter than a regular LED but with a wider angle of spread. An LED is like a small lightbulb, but it doesn't make nearly as much light as a regular lightbulb. A SLD is like a very powerful LED and it can shine a lot more light over a much wider area. That makes it useful in lots of different kinds of devices, like cameras and microscopes, because it can give very bright and focused light with a wide spread.