Spatial and Frequency Dependence of Four-Wave Mixing in Broad-Area Diode Lasers

摘要

By injecting two external optical beams into a broad-area laser diode, four-wave mixing is generated via gain nonlinearities in the device. The nonlinear signals are observed by spectrally analyzing the transverse far-field profile of the emission from the device. By varying the injection angle and oscillation wavelength of one of the injected beams, the spatial and frequency dependence of this nonlinear process is measured. The results support a spatially dependent dynamic carrier concentration model which includes the effects of carrier diffusion. These measurements provide a direct determination of the ambipolar diffusion constant in the device D - 9.5 sq.cm/s. Keywords: Diode lasers; External optical beams; Nonlinear signal; Reprints. (jhd)