Optical Measurement Techniques of Recombination Lifetime Based on the Free Carriers Absorption Effect

Figure 3

Pump and Probe setup in the parallel configuration. The pump pulsed beam and the probe beam impinge on the sample surface. The probe beam is focused on the sample surface, attenuated by the sample, and then detected by the InGaAs photodiode. The diffusion length determines the lateral resolution for the lifetime mapping, so that the probe spot size must be chosen to be more than or, at least, equal to it [56].