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We have studied the saturation of optical absorption in GaInAs/InP quantum wells at room temperature. Using optical excitation from a tunable cw Co:MgF2 laser, we find a saturation intensity of 70 W cm−2 when exciting resonantly at the n=1 heavy-hole exciton, and we deduce values of the nonlinear absorption and refraction coefficients −60 cm W−1 and −0.3 cm2 kW−1, respectively. The saturation intensity in the quantum well is significantly lower than in bulk GaInAs, and also in GaAs quantum wells.

We report the observation of electric field induced exciton energy shifts and photoluminescence quenching in GaInAs/InP multiple quantum wells. We have measured both the photocurrent and photoluminescence spectra from 100 Å wells contained with p+- and n+-InP layers in a conventional p-i-n structure; reverse bias voltages of up to 12 V were applied. The exciton peaks in the photocurrent spectrum are seen to broaden and shift to lower energy; the photoluminescence peak, which is due to n=1 excitonic and free-carrier recombination, also shifts to lower energy and is completely quenched at high voltages. These results are similar to those reported previously for GaAs quantum wells and ascribed to the quantum-confined Stark effect.

We report optical absorption and photoluminescence measurements of excitons in Ga0.47In0.53As/InP multiple quantum wells grown by metalorganic chemical vapor deposition. At 4 K the luminescence linewidth for n=1 heavy-hole excitons is measured to be 7 meV for a 30-period structure with wells of width 154 Å. The absorption spectrum at low temperature shows four peaks which we assign to confined heavy-hole excitons. A theoretical calculation of the energies of these states indicates that the ratio of the conduction-band to valence-band energy discontinuities is 45:55.

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