LAUSR

We present a self-consistent quantum optics approach to calculating the surface-enhanced Raman spectrum of molecules coupled to arbitrarily shaped plasmonic systems. Our treatment is intuitive to use, provides fresh analytical insight into the physics of the Raman scattering near metallic surfaces, and can be applied to a wide range of geometries including resonators, waveguides, and hybrid photonic–plasmonic systems. Our general theory demonstrates that the detected Raman spectrum originates from an interplay between nonlinear light generation and propagation (which also includes the effects of optical quenching). Counterintuitively, at the nonlinear generation stage, we show that the Stokes (anti-Stokes) signal at the molecule location depends on the plasmonic enhancements, through the projected local density of photon states (LDOS), at the anti-Stokes (Stokes) frequency. However, when propagating from the vibrating molecule to the far field, the Stokes (anti-Stokes) emission experiences a plasmonic enh...