Congratuations to Dr. Mittleman! The following story confirms that he is indeed at the forefront of the terahertz revolution! I have always wondered and have asked various engineers if Terahertz could detect biological markers. Does this ability to carry out biological spectroscopy, portend the ability to detect patheogens in our food chain? (At least some foods, such as peanuts should have a moisture level which would for spectroscopic examination). If so, the impact will be huge. Let's hope Dr. Mittleman will comment on this very interesting news and give us some real insights into this story!
First Multi-pixel Terahertz Modulator Created
ScienceDaily (May 26, 2009) — Scientists have for the first time devised a multi-pixel modulator for light waves at terahertz (THz, or 1012 Hz) frequencies. The formal study of THz radiation, which can be described as far-infrared light, dates back many years, but has become increasingly widespread since around 1990, when efficient methods for generating and detecting the radiation become available. The expected applications include carrying out biological spectroscopy and imaging buried structures in semiconductors.
Rice University physicist Daniel Mittleman and his colleagues at Sandia and Los Alamos National Labs use a metamaterial to turn a stream of THz waves off and on. It's called a metamaterial since it consists of an array of microscopic split metal rings. The rings can be controlled by nearby electrodes; modulating the ring's capacitance, in turn, modulates the radiation; that is, the THz light (sometimes called T rays) can be switched so as to pass through or not. The modulator consists of 16 pixels in a 4 x 4 array.
Mittleman reports that this is the first time the wavefront of a THz beam has been under electrical control, which is important because THz wavelengths may be good for imaging and this would be the first step in allowing that by sending light across a whole plane, not just as a linear burst. The switching speed, about 1 MHz, isn't fast compared to today's quickest data transmissions. But, Mittleman say, high bandwidth is not necessary for many of the imaging tasks that will be carried out by T rays. A larger 32 x 32 pixel array is now being designed.
This research is scheduled to be presented during the 2009 Conference on Lasers and Electro-Optics/International Quantum Electronics Conference (CLEO/IQEC) May 31 to June 5 at the Baltimore Convention Center in Baltimore.
Adapted from materials provided by Optical Society of America, via EurekAlert!, a service of AAAS.
1 comment:
Dr. Mittleman commented on the story on the companion group page. I repost it here:
I wouldn't read too much into the comment about biological spectroscopy.
This is a technology designed to improve the capabilities for acquiring terahertz images. How one uses those images is a different question. The
uses, the applications, are enabled (or limited) by the ways in which terahertz radiation interacts with stuff. For instance, terahertz
radiation largely penetrates through cardboard, so that's a useful application. The interactions with biological stuff are possibly interesting, although generally limited by the presence of liquid water.
In any event, our work is aimed at making it easier to make images with terahertz radiation, faster, cheaper, etc., not so much at the end-user applications.
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