Modulation of Laser Light

Analog and digital modulation of semiconductor lasers are introduced. A distinction is made between ideal bits and bits at high and low transmission rates. Important optical modulation techniques such as amplitude modulation (AM) or intensity modulation (IM), pulse-amplitude modulation (PAM), pulse-position modulation (PPM), and pulse-code modulation (PCM) are described. A distinction is made between direct and external modulation (phase and frequency modulation using the linear transversal electro-optic effect and intensity modulation). Practical applications, for example, in directional couplers, are described.