Novel laser for fiber‐optic communication

A new kind of semiconductor laser, developed by Won‐Tien Tsang and his colleagues at Bell Labs, has demonstrated a number of remarkable capabilities that promise to be of considerable importance for fiber‐optic communication. This cleaved‐coupled‐cavity semiconductor laser, nicknamed the $C3$ laser, is able to generate essentially monochromatic pulses of infrared light at repetition rates in excess of a gigahertz. Furthermore, one can electronically switch this pulsed monochromatic output from one wavelength to another on a nanosecond time scale.