# Rayleigh scattering vs raman scattering

1. Jan 22, 2009

### wdlang

both rayleigh scattering and raman scattering are second order processes

the difference is only that the final state of the atom/molecule coindices with the initial state of the atom/molecule in rayleigh scattering, while in raman scattering, the final state is different from the initial state.

since there are many final states, the strength of the raman scattering should by much larger than rayleigh scattering, is not it?

Why people contribute the blue sky to rayleigh scattering but not raman scattering?

2. Jan 23, 2009

### Rajini

Rayleigh..here no energy is lost. Incoming light's wave length and scattered light wave length will be same. This is very good at small wavelengths..
Raman...Here energy is lost (i.e., inelastic process). Very small (1 in 10000000 photon) will suffer Raman scattering. Remaining is Rayleigh scattering. Raman effect makes the molecules to rotate/excite. Also since this is very small and so one cannot say blue color of sky is due to Raman effect.

Last edited: Jan 23, 2009
3. Jan 26, 2009

### wdlang

i do not think the rate of raman scattering is slow than rayleigh scattering

they are both second order processes

4. Jan 26, 2009

### Rajini

Rayleigh it is elastic (incoming and scattered light ray will have same energy) process and Raman is Inelastic (energy may be increased or decreased!) process!..This is what i want to say..May be both effect occur at same rate! But the flux (i mean more photons) is more in Rayleigh. For Rayleigh to occur the scatters should be small than wavelength of photon..