Enhanced Raman scattering from silicon microstructures.

Electromagnetic-structure-resonance enhancement of scattering from Si phonon modes is reported for a number of submicrometer structures. Enhancements of greater, similar100 over the Raman intensity from bulk Si are observed for ~0.1-microm-diameter Si spheres. An analytic calculation of the Raman intensity for this geometry is in good qualitative agreement with the experiment and demonstrates that the enhancement arises from the coupling of both the incident and the scattered fields with the low-order-structure resonances in this high-index dielectric.