Theory of nonlinear refraction near the band edge of a semiconductor

Abstract

Detailed comparisons are made of the results of two approaches to the problem of nonlinear refraction at frequencies just below the band edge in semiconductors. The physical origin o f the nonlinear dispersion is taken to be direct saturation of independent, T 2 -broadened band states in the first model discussed. In the second model the refraction associated with a dynamic Burstein-Moss shift of the absorption edge is considered. Both models predict an extremely large nonlinearity, X (3) ≈ 1 e. s. u., of importance in the field of dispersive optical bistability and consistent with experimental observations of bistability, two-beam differential gain and four-wave mixing.

Nonlinear Absorption in III—V Semiconductors

“…Both (19) and (20) correspond to the broadened n = 1 transition. Equation (19) with yr = 0 was treated earlier in details by the author [lo] and has not been considered further in the present paper.…”

“…Equation (19) with yr = 0 was treated earlier in details by the author [lo] and has not been considered further in the present paper. Equation (20) takes account of the absorption phenomena in the crystals and demands serious considerations. Hence, we will be concerned only with (20)…”

“…Equation (20) takes account of the absorption phenomena in the crystals and demands serious considerations. Hence, we will be concerned only with (20)…”

Capacitive Dilatometer for Measurement of Oscillatory Magnetostriction

“…The index change itself has been associated with the saturation of interband absorption (Miller eta1 1980, Wherrett andHiggins 1982). Similar effects in GaAs are explained in terms of the saturation of excitonic absorption (Gibbs er a1 1979), but arguments have been presented as to the insignificance of the exciton in the InSb case, by Miller er a1 (1980).…”

“…Calculations of the non-linear refraction in the band case have been made by Wherrett and Higgins (1982), (referred to hereafter as WH). They consider the limiting cases implicit in two models.…”