Extraction of carrier lifetime in Ge waveguides using pump probe spectroscopy.

Carrier lifetimes in Ge-on-Si waveguides are deduced using time-resolved infrared transmission pump-probe spectroscopy. Dynamics of pump-induced excess carriers generated in waveguides with varying Ge thickness and width is probed using a CW laser. The lifetimes of these excess carriers strongly depend on the thickness and width of the waveguide due to defect assisted surface recombination. Interface recombination velocities of 0.975×104 cm/s and 1.45×104 cm/s were extracted for the Ge/Si and the Ge/SiO2 interfaces, respectively. [ABSTRACT FROM AUTHOR]