An automatic power-control (APC) loop is incorporated to maintain a constant average optical power. The optical extinction ratio is then maintained over temperature and. d launches the optical signals into an optical fiber. A fiber optic transmitter consists of an interface c rcuit, a source drive to make it compatible with the source drive circuit. An. In fiber optic circuit technology an optical fiber link is used for transferring digital or analogue data in the form light frequency through a cable which has a highly reflective central core. The example when 30mA is injected to LD on graph1 is as follows. If Tc is 60 degrees, Po might be about 1mW. Design of Integrated Circuits for Optical Communications, B. Heck, John Wiley & Sons, 2009.
