(1) Light transmitter
Light transmitter is to achieve electrical / optical conversion of Optical. It consists of a light source, driver and modulator. Its function is to electrical signals from the electrical end machine for light emitted from the light source is modulated, become modulated light, and then the modulated optical signal is coupled into an optical fiber or optical cable to transmit. Electric end machine is conventional electronic communication devices.

Dispersion is due to light waves in different frequency components at different transmission speeds to produce a physical effect of different time delays. Digital transmission, dispersion caused by the optical pulse broadening, resulting in around pulse overlap, causing ISI mathematics signals, resulting in increased error rate; for analog transmission, it will limit the bandwidth, harmonic distortion, making SNR system decreases. Dispersion including material dispersion, waveguide dispersion, mode dispersion, polarization mode dispersion, and other.

WDM (Wavelength Division Multiplexing), Lightwave share with technology, is transmitted simultaneously in a single optical fiber technology multi-wavelength optical signal.