This is a brief introduction to the field of Raman microscopy.
Raman microscopy is a very specialized optical microscopy.
As in any optical microscopy its spatial resolution is close to the micron. Most of the scattered light has the same frequency or color as the laser, but a very tiny amount experiences a frequency shift, which is characteristic of the chemical bonds or molecules present in the material. This inelastic scattering of light is called the Raman effect after C. V. Raman , who discovered it. Raman spectroscopy became a useful technique with the introduction of lasers as a convenient monochromatic light source. It has become widely available only after the introduction of holographic filters to reject the light scattered without frequency change.