A fiber optic transmitter is referred to as a unit that converts an electrical analog or digital signal into a corresponding optical signal. It is one from the components of fiber optics technology that utilizes long versatile glass-like fibers (optical fibers) for transmitting light signals over long distances. The other two components from the fiber optic transmission system are the fiber optic cable television and the optical receiver. Some systems also possess the optical regenerator, which may possibly be vital to boost the degraded light signal (for long distances).

The fiber optic transmitter includes a light emitting diode (LED), or even a solid express laser diode, and signal conditioning electronics. Usually, the transmitter processes the signals of wavelengths of 850, 1310, or 1550 nm. LEDs are broadly applied for brief to moderate transmission distances fiber pigtail , while laser diodes are meant for transmitting signals over long distances. when in comparison with LEDs, laser diodes can couple many occasions more power to optical fiber.

Separate fiber optic transmitters are available for single-mode fibers and multi-mode fibers. Also, some transmitters allow connecting the two single mode and multimode wires in them. Biconic, D4, ESCON, FC, FDDI, LC, Loopback, MTP, MT-RJ, MU, SC, SMA, and ST are some from the typical connectors.

Data rate (data bits transmitted per second), transmitter rise time (the time needed for a signal to alter from the defined 10% to 90% of total power), wavelength (the output wavelength from the transceiver), spectral width (the spectral width from the output signal), and maximum optical output power are considered to be the important performance specifications while selecting a fiber optic transmitter. The pace of the transmitter is expressed regarding its rise time.

To specify a fiber optic transmitter, it is essential to refer to its working temperature, signal inputs (such as TTL, ECL, CMOS video, and RF), pigtail, focusing lens (improving coupling between the transmitter and the fiber), and stand-alone.