Device that emits light by optical amplification based on stimulated emission. This result in light that usually has a very narrow spectrum, that is a single color, and that is coherent, meaning that it can be focused in small spots, sent long distances in laser beams and used in interferometry. One very common laser device is the semiconductor based laser diode.
LEDs (Light Emitting Diodes)
A LED is a semiconductor diode that utilizes electroluminescence to, in a very energy efficient way, generate light. They are small, robust, can be switched on and off and have a long lifetime.
Vertical-cavity surface-emitting laser is a relatively new type of laser diode that offer several advantages over ordinary laser diodes, such as the possibility to stack many in an array in order to generate high optical effect.
Laser where the active media is part of an optical fiber giving several advantages like high power, good optical quality, compact size and long lifetime.