What is Hyper-Rayleigh and what is Hyper-Raman?

[narra]

What is Hyper-Rayleigh and what is Hyper-Raman? Anyone know this?

 

[johng23]

Well rayleigh scattering is the scattering off of particles which are small compared to the wavelength of light. Hyper-rayleigh refers to frequency doubling off of such particles. I don't know all the details - for example, whether you can consider there to be a directional beam of second harmonic light with the same k-vector as the input. This is one thing I'm unclear on - people seem to say that the hyper rayleigh scattering is only diffuse, but I'm not 100% convinced.

I assume hyper-Raman just means that you hit the sample with light at w, and create light at 2w+wp, where wp is the phonon frequency. I think the hyper just implies that it's second harmonic, otherwise it's a normal raman process.