Abstract

The generation of short optical pulses by mode-locking of semiconductor lasers has reached values for the pulse width of 0.5 ps and repetition rates of up to 40 GHz.¹ In principle two techniques are possible to force the resonator modes into a fixed phase relation (mode-locking)²: (a) active mode-locking uses, e.g., acoustooptic or electrooptic modulators which are driven by an external source and (b) the passive technique applies, e.g., nonlinear saturable absorbers where the combination of absorber and laser itself performs the control.

© 1990 Optical Society of America