Achieving high signal-to-noise ratio in transient reflectivity measurements

Transient reflectivity measurements using ultrashort pulse pump-probe techniques can provide very useful information on fast carrier dynamics in semiconductors. Several non-trivial problems encountered in measuring reflectivity changes have been described. These changes can be very small (ΔR/R ∼10 -3 or less) and hence measuring these small changes is not straightforward. The possible solutions in overcoming such problems have been described. Some preliminary results on a GaAs thin film have also been presented.