Ultra Violet & Visible (UV/Vis.) Spectroscopy & its Types

Spectroscopy Process

1.  In UV spectroscopy, the sample is irradiated with the broad spectrum of the UV radiation 
2. If a particular electronic transition matches the energy of a certain band of UV, it will be absorbed.
3. The remaining UV light passes through the sample and is observed From this residual radiation a spectrum is obtained with “gaps” at these discrete energies – this is called an absorption spectrum

Types of Ultra Violet-Visible Spectroscopy

• Acoustic resonance spectroscopy: It is based on sound waves primarily in the audible and ultrasonic regions.

• Auger spectroscopy is a method used to study surfaces of materials on a micro scale. It is often used in connection with electron microscopy.

• Coherent anti-Stokes Raman spectroscopy (CARS) is a recent technique that has high sensitivity and powerful applications for in vivo spectroscopy and imaging.

• Correlation spectroscopy encompasses several types of two-dimensional NMR spectroscopy.

• Deep-level transient spectroscopy measures concentration and analyses parameters of electrically active defects in semiconducting materials

• Dual polarisation interferometry measures the real and imaginary components of the complex refractive index

• Electron phenomenological spectroscopy measures physico-chemical properties and characteristics of electronic structure of multi-component and complex molecular systems.

• Fourier transform spectroscopy is an efficient method for processing spectra data obtained using interferometers. Fourier transform infrared spectroscopy (FTIR) is a common implementation of infrared spectroscopy. NMR also employs Fourier transforms.

• Inelastic electron tunnelling spectroscopy (IETS) uses the changes in current due to inelastic electron-vibration interaction at specific energies that can also measure optically forbidden transitions.

• Laser-Induced Breakdown Spectroscopy (LIBS), also called Laser-induced plasma spectrometry (LIPS)

• Mass spectroscopy is an historical term used to refer to mass spectrometry.

• Mössbauer spectroscopy probes the properties of specific isotopic nuclei in different atomic environments by analyzing the resonant absorption of gamma-rays

• Neutron spin echo spectroscopy measures internal dynamics in proteins and other soft matter systems

• Photoacoustic spectroscopy measures the sound waves produced upon the absorption of radiation.

• Pump-probe spectroscopy can use ultra fast laser pulses to measure reaction intermediates in the femto-second timescale.

• Raman optical activity spectroscopy exploits Raman scattering and optical activity effects to reveal detailed information on chiral centres in molecules.

• Thermal infrared spectroscopy measures thermal radiation emitted from materials and surfaces and is used to determine the type of bonds present in a sample as well as their lattice environment. The techniques are widely used by organic chemists, mineralogists, and planetary scientists.