Fourier transform infrared spectroscopy Berezin Danila Moscow 2013

Plan of a journey Terahertz radiation Its application And research FTIR spectroscopy

Terahertz radiation is an electromagnetic waves Terahertz gap – Hz

THz technology brings better sensing capabilities cancer cavity Visible imageTHz image

THz technology brings better sensing capabilities Visible imageTHz image ceramic knife

The goal is to measure how well a sample absorbs light samplelight

Scanning spectroscopy is the most straightforward way goal – spectrum of absorption

beam sourcesampledetector absorption It shines a monochromatic light beam…

beam sourcesampledetector absorption …and measures how much is absorbed

FT spectroscopy is a less intuitive way to obtain the same information goal – spectrum of absorption

beam sourcesampledetector absorption beam number A beam contains many frequencies of light at once and absorption of that beam is measured

beam sourcesampledetector absorption beam number Next, beam is modified to give a second data point

beam sourcesampledetector absorption beam number Process is repeated many times

Afterwards, computer processing is required

There are still undiscovered nuances How to generate and modify that special beam? What computer processing is required?

moving mirror Wave interference is a key to generate that special beam Michelson interferometer light source beam for the experiment

Processing required is Fourier transform raw datadesired result

FT spectroscopy has an advantage – Fellgett’s advantage Scanning spectroscopy Fourier transform spectroscopy

FTIR spectroscopy – Possible applications – Technology – Advantage

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Fourier transform mirror 1 mirror 2 y 1 /2 x/2 Monochromatic source

Polychromatic source Fourier transform