Raman amplification in ultrasmall silicon-on-insulator wire waveguides.

We measure stimulated Raman gain at 1550 nm in an ultrasmall SOI strip waveguide, cross-section of 0.098 microm2. We obtain signal amplification of up to 0.7 dB in the counter-propagating configuration for a sample length of 4.2 mm and using a diode pump at 1435 nm with powers of <30 mW. The Raman amplifier has a figure-of-merit (FOM) of 57.47 dB/cm/W. This work shows the feasibility of ultrasmall SOI waveguides for the development of SOI-based on-chip optical amplifiers and active photonic integrated circuits.