Two-photon absorption-induced self-phase modulation in GaAs–AlGaAs waveguides for surface-emitted second-harmonic generation

Abstract

Performance-limiting asymmetric distortion is observed in the spectra of fundamental pulses transmitted through GaAs-Al(0.9)Ga(0.1)As multilayer waveguides designed for surface-emitted second-harmonic generation. This behavior is attributed to refractive-index changes resulting from the accumulation of free carriers created by two-photon absorption in the GaAs layers. Numerical simulations of the intensity-dependent spectra by use of the separately measured two-photon absorption coefficient are shown to be in good agreement with the observed spectra.

Kerr and free carrier ultrafast all-optical switching of GaAs/AlAs nanostructures near the three photon edge of GaAs

“…[28][29][30] We find this surprising since we pump at a wavelength twice as long as in the degenerate case. This result enables us to modify efficiently the refractive index with a far detuned pump wavelength.…”

Two-photon-induced photoconductivity enhancement in semiconductor microcavities: a theoretical investigation

“…This effect has been shown to be a predominant one in self-phase modulation [43], and could possibly be the reason why a long delay transmission change is seen after a short pulse in recent experiments on GaN [13]. (12) where m eff is the reduced effective mass of the electron-hole pair, n 0 the linear refractive index and E g the bandgap energy.…”

Ultrafast nonlinear tuning of the reflection properties of AlGaAs photonic crystal waveguides by two-photon absorption

“…From simple free-carrier models for TPA in GaAs-based materials, [18][19][20] it can be shown that the change in refractive index is proportional to the square of the intensity. From simple free-carrier models for TPA in GaAs-based materials, [18][19][20] it can be shown that the change in refractive index is proportional to the square of the intensity.…”

“…This method allows for the comparison between the theoretical values of the free carriers induced index change for patterned and unpatterned AlGaAs, where is defined as 19 = e 2 2 pr 2 ⑀ 0 n 0 m eff This method allows for the comparison between the theoretical values of the free carriers induced index change for patterned and unpatterned AlGaAs, where is defined as 19 = e 2 2 pr 2 ⑀ 0 n 0 m eff…”