Wednesday, September 12, 2012

The World's First Room Temperature Maser!

Run*, don't walk to your local laser store to pick up your new room temperature maser!!! (*please be careful) And while you're at it, check out this week's podcast, which about that very subject.

Okay, technically room temperature masers won't be available commercially for some time. It was only a few weeks ago that Dr. Mark Oxborrow and colleagues at Great Britain's National Physical Laboratory built the first operating, room temperature maser. Dr. Oxborrow says this demonstrates that room temperature masers are possible, and now it will be up to the physics community to improve on the design and put these things to work.

If you're curious about WHY you might want a room temperature maser, just picture this: you're trying to send a message from Mars to earth, and you want the signal to come back loud and clear. So, you use a laser to amplify the signal. That is what lasers do, after all. It's even in their name: LASER is an acronym for Light Amplification by Stimulated Emission of Radiation. So a laser will take a weak signal, and turn it into a nice, clear beam of laser light.

BUT, traditional lasers only amplify optical light. What if your signal is in microwaves? Well, that's where you need  MASER! A maser is simply a LASER that amplifies microwave light (so literally, the 'L' in LASER is replaced by an 'M' for microwaves).

BUT, your maser can only operate at temperatures close to absolute zero (this is due to activity among the atoms of a key component in your maser; low temperatures essentially cool the chaos among the atoms and allow them to do their job and amplify that signal). To cool your maser you need a clunky, expensive cooling system, and that can strongly inhibit how and where masers can be used.

BUT NOT ANYMORE! This new breakthrough could mean that masers will grow in popularity as a tool for communication, or a tool for taking sensitive measurements. A maser can take a small, weak signal and amplify it, much like a microscope amplifies the visible light from something very small.

Every laser (or maser) needs a medium, which is a material that copies the signal one is trying to amplify. Dr. Oxborrow couldn't find the medium (pentacene) he needed in any chemistry labs nearby, so he had to make his own. With whatever pieces of equipment he could scrounge up (including insulation from the fabric store and a clock motor) he then built an oven to grow the pentacene into crystals.

Dr. Oxborrow says the task was a matter of stitching together many areas of science: chemistry, materials science, physics and engineering. And that, he says, is what physicists do best.

"As a physicist, I sometimes joke with people here and say that I am somebody who knows almost nothing about almost everything," said Dr. Oxborrow. "It was the ability to pick up fragments of wisdom in various areas that I think enabled us to sew it together; to construct a device that actually worked."

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