Picosecond photocarrier-lifetime in ErAs:InGaAs at 1.55 μm

This letter reports the measurement of photocarrier lifetime in ErAs:InGaAs epitaxial material grown on InP substrates. The measurement technique is ultrafast time-resolved phototransmission using a 1.55 mum mode-locked erbium-doped fiber laser. A lifetime of 3.56 ps is found in a sample containing an InAlAs smoothing layer, compared to 0.96 ps in a sample without any InAlAs. The difference is explained using a model of ambipolar diffusion of photocarriers. (C) 2003 American Institute of Physics.