Abstract:
At the onset of twenty first century, molecular spectroscopy has been rejuvenated by the advances in various fields like optical instrumentation, nanoscience
and biotechnology. By employing various spectroscopic techniques, rapid progress
has been achieved in understanding molecules and unveiling their interactions.
Molecular detection and characterization techniques have evolved as one of the
most active research areas in science with a huge bandwidth of applications - from
biology to astronomy.
Depending upon the energy scales probed, molecular spectroscopy can be
mainly classified into three different categories: Electronic, vibrational and rotational spectroscopy. The electronic spectroscopy investigates the electronic energy
states of a molecule, which can be probed by ultraviolet or visible radiation. The
vibrational energy states can be probed either by infrared radiation or Raman scattering. The rotational energy states can be probed by microwave radiation. Lasers
have the ability to produce monochromatic photons with a high degree of spatial
and temporal coherence, and hence play a major role in the above mentioned spectroscopic techniques.
