Dr. Mittleman responds to recent post regarding Yissum Research Development Company

Editor's note-the following is Dr. Mittleman's response to the Oct. 19th, 2009 blog post regarding Yissum University. It will be nice to see if he cares to comment about the recent allegations that Teraherz waves tear or damage DNA. As always thank you Dr. Mittleman.

Hi Randy,

I've just tried to post a response to your recent blog post, but I guess

I'm required to have an account that I don't have, in order to post. In

any event, you might want to know that this article contains several

glaring inaccuracies.

First of all, THz quantum cascade lasers are NOT "the only coherent T-ray

sources existing today." Not even close. THz lasers have been around

since the 1960's. There are many other examples. That's nonsense.

Secondly, THz radiation is NOT "comparable to x-rays in terms of their

ability to penetrate opaque substances." Last time I checked, THz

radiation does not penetrate water or even a sheet of aluminum foil.

That's very much different from x-rays, as anybody who has ever been to an

airport could tell you. And thirdly, the implied comment that T-rays will

somehow replace or supplant any existing medical imaging technology is

utterly ludicrous. There might, *MIGHT*, be certain niche applications in

the field of medical diagnostics where THz radiation is useful. But that

has yet to be established, and there is no way on earth that you'll ever

replace x-rays with T-rays.

Most practicing researchers are aware that this kind of hype only serves to

damage the credibility of the field, and seek to avoid it. I do not mean

to diminish the interesting work of the folks at Hebrew University. I'm

making no comment on the significance of their work, only on the way

they've chosen to advertise it.

You can feel free to post this comment on your blog, if you don't change

any of the text. And feel free to attribute it to me.

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Dr. Daniel Mittleman Phone: (713) 348-5452

Rice University FAX: (713) 348-5686

ECE Dept., MS-366 E-mail: daniel@rice.edu

6100 Main St. URL: www-ece.rice.edu/~daniel/Mittleman.html

Houston, TX 77005

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New Thz technology 400 times higher gain

This is a really interesting article. I hope someone can provide us with more information.


Yissum Research Development Company of the Hebrew University of Jerusalem Ltd., the technology transfer arm of the University, today announced that Professor L.D. Shvartsman and Professor B. Laikhtman, from the Racah Institute of Physics at the Hebrew University of Jerusalem, have invented a novel design of TeraHertz-ray, or T-ray, lasers. Using nanostructures which are based on semiconductors with special properties, the novel device will have 400 times higher gain than THz quantum cascade lasers, the only coherent T-ray sources existing today , This invention will make T-ray based cameras and spectrometers practical, ushering a new era in security and medical imaging.

T-rays are electromagnetic waves with a wavelength shorter than microwave but longer than infrared. They are extremely attractive for various imaging applications due to three main reasons: they can penetrate through various substances, including clothing and even walls, they are harmless, and therefore allow a safe use for healthcare and homeland security applications and they can detect various chemicals, in particular explosives. Thus, T-ray-based devices can detect hidden weapons and explosives, as well as improve patient care and safety in healthcare facilities by allowing an unlimited number of exposures for medical examinations. However, despite all the advantages of T-rays, they are barely used due to lack of T-ray emitters that will generate powerful, coherent and adjustable terahertz waves. The invention of Professor Laikhtman and Professor Shvartsman overcomes these current limitations and suggests the design of effective THz lasers.

"TeraHertz rays are the imaging method of the future. They are comparable to X-rays in terms of their ability to penetrate opaque substances, but more importantly, they are harmless," said Yaacov Michlin, CEO of Yissum. "The novel method to produce efficient T-ray emitters will enable the use of this important imaging source for various applications, including security and medical applications."