Ramansäteilyyn

Ramansäteilyyn refers to inelastic scattering of light, a phenomenon observed when light interacts with matter. Discovered by Indian physicist C.V. Raman in 1928, it occurs when photons from an incident light beam collide with molecules and transfer some of their energy to or gain energy from these molecules. This energy exchange results in scattered photons having different frequencies (and therefore different wavelengths and colors) than the incident light.

The inelastic scattering can be broadly categorized into two types: Stokes scattering and anti-Stokes scattering. In Stokes scattering, the scattered photons have lower energy (longer wavelength) than the incident photons, meaning energy has been transferred to the molecule, exciting it to a higher vibrational or rotational energy state. Conversely, in anti-Stokes scattering, the scattered photons have higher energy (shorter wavelength), indicating that the molecule was already in an excited state and transferred some of its energy to the photon, returning to a lower energy state.

The energy difference between the incident and scattered photons corresponds to specific vibrational or rotational energy levels within the molecule. This characteristic energy spectrum provides a unique fingerprint for identifying the substance and studying its molecular structure and dynamics. Raman spectroscopy, a technique based on this principle, is widely used in various scientific fields, including chemistry, physics, materials science, and biology, for analysis and characterization.