Measurement of the Two-Photon Absorption Coefficient in a GaAs/AlGaAs Quantum Well Laser.

摘要

The two photon absorption (TPA) coefficient has been measured for a single-mode GaAs/AlGaAs quantum well laser at 0.86 microns, near the lasing wavelength of 0.83 microns. Picosecond laser pulses were employed to resolve the ultrafast TPA from long-lived carrier-dependent effects. The TPA coefficient was found to be 31 + or - 6 cm/GW, which corresponds to a value of (5.7 + or - 1.2) x 10 to the -11th power esu for the imaginary part of the third-order nonlinear susceptibility. At wavelengths near the quantum well exciton, no strong resonance enhancement of the two-photon transition was observed, and the coefficient appears to be characteristic of the AlGaAs cladding layers. Keywords: Reprints. (JHD)