Applicable in velocities from subsonic to hypersonic
Applicable in temperatures from cryogenic to combustion
Simultaneous measurement of all major species including N2, O2, H2, H2O, CO2
Spontaneous Raman Scattering Principle
Pure Rotational Raman Scattering
O and S Branch possible
S branch shown
Rotation-vibration Raman Scattering
Q-branch
Data Analysis
Density determined from area under the rotational lines
Temperature determined from rotational or vibrational Boltzmann distribution
N0: atoms in the lower vibrational state
N1: atoms in the higher vibrational state
g0: degeneracy of the lower vibrational state (number of orbitals of the same energy)
g1: degeneracy of the higher vibrational state
E1 – E0: energy difference between these two vibrational states
k: Boltzmann's constant
T: temperature in Kelvin
