Measurement of linewidth broadening factor in gain-switched InGaAsP injection lasers by CHP method

Abstract

First measurements of the semiconductor laser linewidth broadening factor α using a recently proposed CHP (chirp-halfwidth product) method are reported. Gain-switched optical pulses have been generated by sinusoidal RF and comb generator drive. The simultaneous recording of streak-camera and monochromator traces provides the required data for determination of α. The values of α between 6 and 7.5 are obtained for a 1.3 μm mesa laser. Computer simulations predict that the CHP formula should provide an estimate of α within ±15% for either comb generator or hard sinusoidal drive.