How did the discovery of the Raman Effect transform spectroscopy as a scientific tool? Discuss its applications.

Announced by C.V. Raman on 28 February 1928 at the Indian Association for the Cultivation of Science, Kolkata — now commemorated as National Science Day [2] — the Raman Effect turned light scattering into a direct probe of molecular structure, making spectroscopy an everyday analytical instrument rather than a laboratory curiosity.

How it transformed spectroscopy

• Inelastic scattering: Raman showed that a small part of scattered light emerges at wavelengths different from the incident light, because incoming photons exchange energy with the molecule [1]. This was a new observable, distinct from classical absorption and emission.
• Molecular fingerprinting: because the shift depends on the bonds present, every substance leaves a characteristic signature — the Nobel citation records that the effect "opened new routes to our knowledge of the structure of matter" [1].
• A working analytical method: the phenomenon "is used to analyse different types of material" [1] — typically without destroying the sample, and later made routine by lasers as intense monochromatic sources.
• Indigenous origin: the method emerged from a university-scale Indian laboratory before India had national research institutions, and is carried forward by the Raman Research Institute [2].

Applications

• Chemistry and materials: identification of compounds, crystal structure and phase, and quality checks on pharmaceuticals and industrial materials [1].
• Planetary science and astrobiology: NASA's Perseverance rover carries SHERLOC, a deep-UV Raman and fluorescence spectrometer that detects organics and minerals altered by water on Mars — searching for signs of past microbial life [3].
• Security and forensics: portable Raman analysers permit rapid, non-contact identification of unknown substances in the field [1].

The Indian gap

• India's GERD stands near 0.64% of GDP [4], with government funding about 64% and industry only 36% [5] — squeezing the open-ended science Raman himself did.

Raman's discovery converted a subtle optical effect into a universal diagnostic language for matter. Sustaining that legacy requires the ANRF-led push to fund curiosity-driven research in universities, so that Indian laboratories again produce tools the world adopts.