Polarization dependence of the two-photon Franz-Keldysh effect

TL;DR

This paper investigates how a constant electric field influences two-photon absorption in semiconductors, revealing a strong polarization dependence linked to intraband dynamics, using theoretical models for GaAs.

Contribution

It introduces a theoretical analysis of polarization effects on two-photon electroabsorption in semiconductors under electric fields, comparing two band structure models.

Findings

Strong polarization dependence of two-photon electroabsorption spectrum

Dependence attributed to intraband dynamics effects

Predictions consistent across different band models

Abstract

The effect of a constant electric field on two-photon absorption in a direct band gap semiconductor is calculated using an independent-particle theory. Two band structure models for GaAs are used: a two-band parabolic model and an eight-band "k dot p" model. Both predict a strong dependence of the two-photon electroabsorption spectrum on the polarization of the light with respect to the constant field. We attribute the polarization dependence to the strong effect of a constant field on intraband dynamics.