Picosecond Excite-Probe and Transient Grating Studies of GaInAsP

Abstract

We have previously reported ultrafast saturation recovery in 0.860 eV (1.45 μm) bandgap GaxIn1–xAsyP1-y (x = 0.35, y = 0.78) [1], at high carrier densities (> l019 cm–3) using 5 psec pulses at 1.054 μm (1.176 eV). The extremely rapid (~ 10 psec) recovery was attributed to Auger recombination, and was consistent with values for the Auger coefficient measured by Sermage et al [2] at lower carrier densities, and subsequently by Wintner and Ippen [3]. Recently Islam et al [4] have carried out 2-pulse grating measurements on GaInAsP. This paper extends these studies to the 3-pulse transient grating technique with samples having different bandgap energies.