Generation of 4 ps light pulses from directly modulated V-groove lasers

4 ps light pulses at repetition rates up to 10 MHz with an output power of some milliwatts are generated at 840 nm by directly modulating commercial GaAlAs V-groove lasers by specially designed avalanche generators. The pulses are measured using an ultrafast streak camera and present the fastest light pulses obtained until now by direct modulation of a semiconductor laser. The avalanche generators produce pulses of 125¿200 ps FWHM with voltages up to 25 and 38 V, respectively.