Rensselaer Spaces: The Terahertz Cleanroom

by Gabrielle DeMarco on January 4, 2011

An optics quiz: What is between microwaves and infrared light on the electromagnetic spectrum? Something very special sits in that electromagnetic gap – terahertz wave radiation, or T-rays.

Welcome to the cleanroom of the Center for Terahertz Technology. Yes, that is actually me in the stunning cleanroom hat talking to researcher Jianming Dai. This post is part of a continued effort of The Approach to bring you into the sophisticated research spaces that are housed at Rensselaer, but few of us ever get the chance in poke around in. Except you might not want to poke around in this lab too much. A small amount of dust or one badly placed elbow could damage one of the hundreds of piece of optics equipment in the lab. You could also burn your retina if you look at one of the ultra powerful lasers the wrong way. Needless to say, I stepped around very lightly.

The cleanroom is just one of the laboratory facilities within the center. It is a very large space, which is solely dedicated to producing and studying T-rays, which have historically been very difficult to produce even in the lab. Those large grey curtains can be pulled across at various spots to block off different sections of the lab. There are several large optical tables that are resistant to vibration. This is important so that the laser beams used to generate T-rays hit the correct targets. On each table is an array of lasers, lenses, and mirrors that produce, shape, and direct the laser beam respectively to produce and manipulate the T-rays. Various spectrometers and oscilloscopes throughout the lab measure the properties of the light and voltage produced.

The team of researchers within the Center for Terahertz Technology are among the top terahertz scientists in the world. Their breakthroughs in developing T-ray emitters and detectors are providing researchers and companies around the world with important new technologies. Their research has even been used by NASA to study damage to the hulls of space shuttles.  

Why go to all this trouble and set up so many mirrors and lasers to produce these rays? Many materials are transparent to terahertz radiation. They also offer many advantages over conventional imaging and material detection techniques. Unlike x-rays, terahertz radiation is safe for human cells, which make them ideal for security checks and medical imaging. They also go further than x-rays by producing something akin to a material’s fingerprint or signature. The unique responses of different materials within the THz range provide information generally absent in optical, X-ray and NMR images. This fingerprinting of materials has important potential for use in uncovering explosive materials or even drugs without opening or even getting near a potentially dangerous object.

Learn more about the center here. Also, Check out this recent article on remote sensing using terahertz.