Abstract

The gain-switching approach to ultrashort pulse generation consists in the direct modulation of a DFB laser with current pulses having a suitable width to excite only the first peak of the relaxation oscillations.^1,3 The optical pulses at the laser output exhibit a short duration and a strong chirp which distorts and broadens the corresponding spectrum. A further reduction of the pulsewidth can be obtained by passive compression, coupling the laser beam into a fibre with negative dispersion.

© 1994 IEEE