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After 60 Years, a Room-Temperature Maser
gbrumfiel writes "Before there were lasers, there were masers: systems that amplified microwaves instead of light. Solid state masers are used in a variety of applications, including deep space communication, but they've never been as popular as lasers, in part because they have to be cooled to near absolute zero in order to work. Now a team of British physicists have built a room-temperature maser using some spare chemicals and a laser they bought off of eBay. The new device is 100 million times as powerful as existing masers and might revolutionize telecommunications."
then give it out freely and let man really use it wickedly
wow.
Mounted to frickin' lark's heads.
[/pinky in mouth]
Why does this remind me of so many cold fusion stories I've seen?
~S
How long until we get something along these lines?
...let me know when they make a working room-temperature faser.
Does this mean I can have my very own Goa'uld staff weapon yet?
While this may be the worlds' first room-temperature solid-state maser, it certainly isn't the first room temperature maser. Standard hydrogen masers (the ones that help NIST tell what time it is) are certainly not cryogenic.
Just to nitpick a bit, 10 K (as the article mentions) is really quite easy to achieve with off-the-shelf cryogenic equipment, and not the "near absolute zero" as the summary sort of suggests (I usually reserve this for 1 K, but maybe this is just me).
isn't really truly evil unless you can.
if this is supposed to be a new economy, how come they still want my old fashioned money?
"Using spare chemicals, a laser bought on eBay and angst from a late-night argument, physicists have got the world's first room-temperature microwave laser working."
Getting this to work reliably is going to require a reliable source of angst. Any high school should do the trick.
This is frikken huge news, if it pans out. I'm old enough to remember when news of the first MASERs came out. Before LASERs.
Just the applications alone in Atomic Spectroscopy, ECR technology, high power communications- do you realize just how sloppy the frequency spread of Klystrons and similar devices are? Accelerator Technology, space charge cooling,... the implications for Fusion research...
Super Wow.
If it pans out.
Neat, but generating high power, coherent microwaves is pretty simple now, not so before III-V semiconductors. I have read about their usefulness for space power beaming.
This is a thread I'll get my popcorn for.
This may drain all of the angst out of the entire school, altering youth forever.
... you could vaporize a man sized object from space...
Considering this is Nature, the lack of any numbers, or even a link to a paper are very disappointing. The writing style itself makes it sound like they've just turned lead into gold as well...
I want diagrams, temperatures, power figures, etc. Not waffle. I expect better.
Actually, the link to the proper paper is at the bottom in the references part, with a good description of results. Here is a direct link: http://www.nature.com/nature/journal/v488/n7411/pdf/nature11339.pdf
Now this is my sort of science! I expect that this discovery has been made several times before with a predictable outcome; hence its "undiscovered" status.
Here we unlock microwave power plants, next unlock is fusion so get excited!
For an example, this group was creating room-temperature masers in the mid-90's: http://walsworth.physics.harvard.edu/research/pastprojects/atomicclock.html
One demanding citations of work would expect to know to look in the citations section.
"most in the field gave up on masers and moved on to lasers, which use the same principles of physics, but work with optical light instead of microwaves."
what the hell? microwaves are still EM radiation. EM radiation is light. thus a maser is just a regular laser in a different wavelength, no more different from a green laser vs a red laser....which are also just different wavelengths of light.
The next step seems to be a portable power supply...
= Maser Gun! Nice.
It may be 100 Million times as strong as its predecessor, but in absolute terms it required 1.5 KILOWATTS of input power to generate 100 MICROWATTS of output power. Not the most efficient thing in the world - that's an input:output power ratio of 15 million:1 (nearly 72 dB).
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
Yeah, but even if you had NO improvement and illuminated the crystal with a 30 dBm (1 watt) laser, let's see here. 30 dBm - 72 dB = -42 dBm. That's still a lot of power. Especially if you're beaming data in a narrow, coherent beam at something at 30 or 70 GHz.
Don't try to scare people away by bringing up terms which you don't understand. A microwatt is a lot of power at these frequencies.
Perhaps, but when the incoming microwave signal is measured in nanowatts or picowatts, a gain of 100 million is pretty damned awesome. Bulk electrical power is easy to come by; a stronger incoming signal is very hard to come by. Depending on the application, who cares if the efficiency of the equipment is lousy.
A better way to look at "efficiency" is to consider how much energy is required to transmit some unit of information across a certain distance. 1.5 kW electrical power is not actually all that much power for microwave transmission applications, especially if it means that the transmitter power can be turned down by, say, a factor of 10.
I should have quoted this part of the article: "When configured as an oscillator, the solid-state maser’s measured output power of around 10 decibel milliwatts is approximately 100 million times greater than that of an atomic hydrogen maser, which oscillates at a similar frequency (about 1.42 gigahertz)." [emphasis mine].
I was not referring to it's gain as an amplifier; rather it's rather meager output as a 1.42 GHz oscillator. For 1.5 kW in, I'd expect at least half that much power out to be considered useful at all (that's for a solid-state or tube oscillator).
Here's a tunable VCO that uses 50mW to generate 2.5 mW from 1.277 to 1.691 GHz. That's 20:1.
The only use this thing has as an oscillator over other means are possibly frequency stability and coherence, neither of which are major concerns with regard to microwave transmission applications.
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
The only use this thing has as an oscillator over other means are possibly frequency stability and coherence, neither of which are major concerns with regard to microwave transmission applications.
The efficiency is crap; certainly this maser is not a transmitter, unfortunately. A hugely powerful pencil thin coherent microwave beam is pretty interesting to think about.
Frequency stability is actually a major issue at higher microwave frequencies. Yes, a high quality crystal oscillator is pretty darn stable, but they are limited to fundamental resonances in low VHF; microwave frequencies require overtone oscillation or frequency multiplication, which both introduce noise and instability. This is obviously not a show stopper as we have been using microwave comms for half a century, but R&D is still ongoing.
A maser, on the other hand, can be used to build an atomic clock; it's stability at high frequencies really kicks the snot out of any XO. Even if it doesn't find common applications in the field, it will almost certain find applications in lab frequency references, GPS systems, satellites, etc.
Weak signal reception sounds like a huge potential application. This may obsolete the GaAsFET for weak signal amplification. Although being at room temperature, I doubt it could reach a 17k noise floor.
Considering that he got that first try with a far from perfect crystal he cooked up in a hurry, it's reasonable to expect some rapid improvements now that we know it''s not a complete waste of time.
Yes, you can use liquid helium to cool it, and it's probably easier than running your own cryogenic cooling pumps. But unfortunately it's not cheap - it's about $10/liter, vs. less than $1/liter for liquid hydrogen or $0.10 for liquid nitrogen. And there's a limited supply of helium in the world, so it's likely to be getting more expensives. (Liquid H2 temperature is about 20K, so it's not quite enough for a maser that needs to be 10K.)
Room-temperature masers are much more practical. And they're a lot easier to attach to sharks.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
I agree completely (that's why I said "Good start"), but the wild, rabid enthusiasm of other commenters need to take that into account. They obviously didn't RFTA, so they hear 'maser' and thought it meant 'death ray'.
PS - I think you may have made it onto the DEA's watch list with your phrase "crystal he cooked up in a hurry". :-)
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
Don't try to scare people away by bringing up terms which you don't understand. A microwatt is a lot of power at these frequencies.
I definitely understand the terms and agree that -42dBm is a useful amount of power at 60GHz. Thanks for the ad hominem.
My point is that if you've got all that power and all that real estate to run such a large and terribly inefficient signal source, what does using it actually give you?
In any real-world comms application I can think of (outside the laboratory), spatial and temporal coherence are not needed and introduce more problems that they solve. The beamwidth is narrow but is still diffraction-limited; the same limit can easily be achieved with normal high gain antennas (at 30-70GHz, high gain antennas are tiny).
If for some reason you need temporal coherence, your only choices of modulation are by direct modulation of the pump laser; that is, mixing (heterodyning) the output of the maser with a modulating signal by conventional means (semiconductor mixer, for instance) would destroy the coherence. I suppose you could do the mixing in a non-linear waveguide setup, but that would be a lot of microwave plumbing. Similar results can be achieved using regular old polarized antennas without limiting your modulation choices.
In other words, using a maser for comms is a solution looking for a problem.
In your example, a 1 watt optical laser would be at best 45% efficient. So you're looking at about 2.2 Watts input for 63 uW out. A 20 GHz DRO followed by a doubler or tripler would give you significantly more output power per unit of input power, as well as be tunable and tiny. The DRO in the link consumes a maximum of 31.7 dBm of power and emits 13 dBm of RF. an IMPATT diode would be another good choice.
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.