Carrier-induced change in refractive index of InP, GaAs and InGaAsP

The change in refractive index Delta n produced by injection of free carriers in InP, GaAs, and InGaAsP is theoretically estimated. Bandfilling (Burstein-Moss effect), bandgap shrinkage, and free-carrier absorption (plasma effect) are included. Carrier concentrations of 10/sup 16//cm/sup 3/ to 10/sup 19//cm/sup 3/ and photon energies of 0.8 to 2.0 eV are considered. Predictions for Delta n are in reasonably good agreement with the limited experimental data available. Refractive index changes as large as 10/sup -2/ are predicted for carrier concentrations of 10/sup 8//cm/sup 3/ suggested that low-loss optical phase modulators and switches using carrier injection are feasible in these materials.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>