TIFR develops new Terahertz device

NEW DELHI: The Tata Institute of Fundamental Research (TIFR) at Mumbai has developed a new terahertz (THZ) source that produces maximum energy in a compact, table top device. This could have widespread applications in security scanners and medical imaging. Terahertz refers to a region that lies between the microwave and infrared portions of the electromagnetic radiation (light).

“While bright sources do exist in this region, they are usually accelerator-based and hence big in size. The available table top sources provide less radiationthe most common ones based on semiconductor antennas providing the least”, said G Ravindra Kumar, senior professor in the department of nuclear and atomic physics at TIFR.

The table top devices widely used so far, have a femtosecond (also known as ultrafast) infrared laser driving a semiconductor sample that emits THZ radiation. To overcome the low efficiency, the TIFR team consisting of Dr. Indranuj Dey, Kumar and others, used a similar but more powerful laser to generate THZ from common liquids like water, alcohol etc.

“One of the reasons liquids were not being employed for producing THZ is their ability to absorb THZ immediately. The research at TIFR establishes that despite absorption, liquids radiate plenty of THZ for consumption. The device can be made more compact”, adds Kumar. The team at TIFR employed liquid plasma which lasts for a longer duration on a compact table top device. The team claims to produce the most powerful THZ radiation in the world. The TIFR discovery has been published in the prestigious journal Nature Communications. The liquid terahertz source can find applications in various domains such as molecular science, semiconductor and plasma physics, medicine and archaeology among others.

“These can be used as alternatives to x-ray imaging as they don’t harm the human body”, says Kumar.