What are the light sources offiber optics?

Light sources of fiber optics are used to inject light into a fiber optic cable. There are two varieties of light sources: laser diodes and light emitting diodes (LEDs). They're further differentiated by the wavelength and the type of cable.

LEDs are economical, slow in speed, easy to handle, multi mode-only, and have a wide output pattern.

Laser diodes are of expensive and faster than LED's, allow single-mode or multi mode both, and have a narrow output pattern.