Coupled-mode theory is used to calculate Raman gain and spontaneous efficiency in silicon waveguides with cross-sectional areas ranging from 0.16 to 16 μm<sup>2</sup> . We find a monotonic increase in the Raman gain as the waveguide cross section decreases for the range of dimensions considered. It is also found that mode coupling between the Stokes modes is insignificant, and thus polarization multiplexing is possible. The results also demonstrate that for submicrometer waveguide dimensions the Einstein relation between spontaneous efficiency and stimulated gain no longer holds.
© 2003 Optical Society of America
(130.0130) Integrated optics : Integrated optics
(130.4310) Integrated optics : Nonlinear
(190.4390) Nonlinear optics : Nonlinear optics, integrated optics
(190.5650) Nonlinear optics : Raman effect
(190.5890) Nonlinear optics : Scattering, stimulated
D. Dimitropoulos, B. Houshmand, R. Claps, and B. Jalali, "Coupled-mode theory of the Raman effect in silicon-on-insulator waveguides," Opt. Lett. 28, 1954-1956 (2003)