Improvement in the frequency response of 1.3-μm buried heterostructure InAsP lasers

Abstract

In this paper we present results of small signal response measurements of 1.3µm strained InAsP buried heterostructure multiple quantum well lasers obtained using optical and electrical excitation. Direct modulation of the carrier population in the quantum wells with a femtosecond pulse from an Optical Parametric Oscillator yields frequency response traces with modulation bandwidths of ∼ 6 GHz at biases of 1.5 and 1.8× threshold. These results contrast with those obtained with electrical excitation for which modulation bandwiths of ∼ 3 GHz are obtained at the same DC bias conditions. Analysis of the modulation traces obtained with optical excitation show that in these lasers, transport processes play a dominant role in the frequency response.