Digital signals are sent directly to a light source (LED or laser diode) that converts them into light waves. The light waves travel through the optical fibre from the source to the destination using total internal reflection. A photodetector (photocell) receives the light pulses. Fiber-optic communication is a form of optical communication for transmitting information from one place to another by sending pulses of infrared or visible light through an optical fiber. Optical fibre is preferred over electrical cabling for long-distance transmission. anced modulation formats, and digital signal processing techniques. The process kicks. To meet the demands of growing traffic, the data rates of fiber optic communication systems (FOCSs) need to be increased.