Monolithic colliding pulse mode-locked (CPM) multiple quantum well lasers
generating optical pulses as short as 600 femtoseconds are reported. The CPM
laser is built on a single chip of InGaAs/InGaAsP multiple quantum well
laser. The pulse repetition rates are synchronized with an rf synthesizer up
to 40 GHz in hybrid mode-locking scheme. In passive mode-locking scheme, a
record high repetition rate of 350 GHz has been achieved. All the
sub-picosecond pulses obtained have pulse shapes of sech2 and
transform-limited timebandwidth products between 0.30 to 0.34. This new
optical source is very useful for ultra-high speed optical switching and
optical logic in optical fibers, and ultra-long distance optical soliton
transmissions.