Thz radiation - Elly Nuttall
The most common question I get asked whenever I speak to someone about my research is what actually is THz radiation. Unlike x-ray/microwave/ IR not many people have heard of THz radiation. This is because only in recent decades have we been actually able to source and detect THz radiation. Only now are we looking at potential applications of THz radiation - and its lots of things! Unlike X-ray radiation, which has shorter wavelength and hence can cause damage to biological molecules and tissues, THz radiation has a much longer wavelength and therefore is not harmful. It has already been shown that THz radiation is able to detect a variety of skin cancers, detect illicit drugs in packaging and distinguish between polymorphs. The future of THz is looking very promising!
My masters research project involved analysing a number of fundamental liquids (H2O, MeOH, EtOH) with a THz time domain spectrometer (THz-TDS. See attached photo. The black box on the right is the laser. It travels round all the mirrors before reaching the box on the left, where the sample is.) Although these liquids play a pivotal role in human activity and development, there is currently still a lack of accurate knowledge on the molecular dynamics of liquids; Specifically hydrogen bonding, which has a crucial role in many chemical and biological processes. The complex structure of water, ( owing to its ability to form 4 hydrogen bonds) has led to extensive research into its structural characteristics. A hydrogen bonds lifetime occurs on the picosecond (ps) timescale and as such makes THz radiation ideal for probing them ( since THz frequencies correspond to the ps time-scale.) In my project I produced THz absorption spectrums for the above liquids at temperatures ranging from 288 K to 313 K ( 15'C-40'C.). Continued in comments....