Pulse asymmetry in actively modelocked InGaAsP lasers

Abstract The temporal intensity profiles of modelocked pulses produced from an external-cavity InGaAsP semiconductor laser are investigated. The pulse asymmetry that is observed is shown to be consistent with the form of an asymmetric sech 2 pulseshape. The resultant bandwidth-duration products of the laser pulses can take a range of values, but can be shown to be transform limited after consideration of the particular pulseshape involved.