Talk:Maser

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[edit] Layout of the page

Hi,

I see your commitment to maintain this page. You are doing a great job. Whittin only a few hours you corrected all my mistakes. So let me tell you my motivations one time and then you can decide:

My comment about commercially available devices was not meant to be "strict"! I am a "rubidium-maser-man" myself (those are not available commercially), and I thought that it would be a little bit pedantic to talk about my own stuff. Therefore I thought that Hydrogen maser was a good example, and it is: thousands of units have been produced in 20 or so countries. If this is not a maser, then what is? On the other hand it should not be a synonym of all the microwave spectroscopy science...

My point is the following: This page should contain the good information so that for example a high school student can learn what a maser is. At least the first few sections should fill that need.

It is not by having an exhaustive list of all lasing transitions that we will achieve that goal (there are thousands of them). Or by trying to list all the papers where the letters "aser" appeared.

I have read somewhere (I can not remember the exact reference, sorry) that at some point during the 1950-1960s the word "maser" was so popular in the literature that the physical review issued a memo saying that they would not accept any more publication on that subject. This phenomenon hapens all the time. When a word is so widely used that it does not mean anything then we have to come back to the original definition:

The usage should be modern and corresponding to the original definition as much as possible.

This is particularly true if there are other words for the other uses. For that matter, we should put the emphasis on the original concept:

i) It is a device,

ii) It covers the low frequency part of the spectrum. (It is difficult, I agree to call a "laser" someting that emits in the RF range).

Astronomy: This is not my field, therefore it is difficult for me to comment on that, but I will do it anyway! If someone is offended by my comment, I deeply apologize:

I suspect that the word maser was used in astronomy to refer to some mechanisms similar to the one seen in a maser (laser): i) a kind of emission due to a kind of population inversion. ii) production of coherent radiation or photon corelations, etc... iii) amplification, or spontaneous creation.

If this is the case then we are still talking of "maser-like" effects, not "maser".

Also, the field of quantum optics has made a lot of progress and is now well known. I am certain that researchers now describe their observations directly in terms of fundamental processes, and do not use the ambiguous word (in their case) "maser".

For those reasons, the astronomical and molecular data should not be placed at the top of the page. I am not saying that it should not be there, just that there should be separate sections or pages, including a description of the concept.

Now, for all those masers were only one paper was published in the 60's. They were prototypes or studies that slowly evolved to the modern lasers or masers. I do not think that they should be discussed at least in the first few sections and it would be very usefull to give the reference and mentioning that this belongs to the past.

Finally, I acknowledge the work by the Smithsonian/Harvard group (Walsworth, Vessot, Phillips and co- workers). I think that there should be some sections about all of their current research (noble gas maser and other types). (There is a link to their page).

One last comment: The book of Singer is really obsolete! The book of Vanier and Audoin is available on the internet (not free), but is not really an introduction. May be someone has an idea for a better reference.

Alain Michaud 23:08, 4 December 2005 (UTC)

  • No, no, please do talk about your own stuff, with the reminder that this is not a forum for original research. I agree, in general, that having an introduction which makes the subject accessible to the the layman should be a goal. However, there is always the danger of over-simplifying; which i think is where this page has been in the past. I think people should be able to come immdeiately to this page and see, generally, what a maser is. However, generally, what a maser is depends on the context your approaching the subject from ... ie., did you run into masers in astronomy, did you run into masers in an older text (1950-1960's), did you run into masers that operate in rf or microwave, etc. The point is, this page should, i think, provide some explication for "why" the term maser is sometimes confusing, and why one must approach the subject with care. To state that a maser is a "microwave-aser" is just too misleading at the outset.
On the other hand, i for one would very much like to see an exhaustive list of masing-type devices, and references of where they are referred to as such. If changing the order of the article allows for this, with a soft introduction, followed by details -- that would be just fine by me ( however, there are some major contributors to this page that may disagree (Srleffler?). I think the page is finally starting to approach a level of usefullness where having a schematic and some pictures would be quite nice as well.
Finally, the astronomy bit i think needs to be handled with care. There are alot of papers obout masers in astronomy, and so marginalizing this in any way could be problematic. That is, i do not think that we should suggest that common usage does not include astronomy usage, and so, an introduction, i think, should at least mention this briefly. Also, yes i agree, the Singer book is obsolete, but i think still a very interesting text. Perhaps it should be mentioned in a history section, where if you can find (perhaps), and expand on this anecdote you recalled about "physical review issued a memo saying that they would not accept any more publication on that subject;" that would be quote nice as well, and perhaps shed some light on the laser/maser debate. For me a goal is to homogenize the language so that people can speak to each other without getting into arguments; and without forgetting history at the same time. Cypa 01:50, 5 December 2005 (UTC)


  • Welcome, Alain! This page can certainly use some attention from a "rubidium-maser-man". I'm a solid-state laser guy myself, so while I am interested in this subject, I don't know a lot about it. I agree 100% that the thing that should appear first on the page is a good, general, and correct explanation of what a maser is and how it works, such that a layperson can understand it. This can be followed up by more specific details further down the page.
One of the things that has complicated this page in the past was a debate about terminology. If you read the talk page here and at laser, you'll see that there has been some debate about what the acronym "MASER" actually stands for, and whether "maser" or "laser" is the correct generic term for all devices of this type. The text currently on the page is a hard-won compromise position between different people. Part of the problem is that we don't have anyone who has a broad overview of the whole field. As a laser guy, it's "obvious" to me that "laser" is the correct generic term. To Cypa, it's equally obvious that "maser" is the correct term. Unless he is completely alone in that opinion (among current researchers, not historical usage), the page needs to reflect the disagreement without trying to settle it. This is the Wikipedia "NPOV" requirement—we don't settle disputes here, we document them.
I think the astronomical usage of "maser" is important, and I have no reason to believe it is not current. One way of dealing with this might be to split off that material onto a separate page, e.g. maser (astronomy), with disambiguation links between the two pages. I think, though, that the two things are closely related enough to be treated on a single page. Some confusion has been created on the page, though, by failing to distinguish between the two usages.
My impression is that the astronomical "masers" are closer to the device you are familiar with than you might think. A traditional maser consists of an inverted gain medium that amplifies light by stimulated emission, and a cavity that provides feedback. I believe the astronomical "masers" are superradiant systems—they consist of an inverted gain medium (ionized interstellar gas, pumped by starlight), which amplifies light by stimulated emission. There is no feedback cavity, but instead the gain medium is so long that significant stimulated emission can still occur. Essentially a travelling-wave "mode" builds up in the gain medium, resulting in significant output, distinct from normal spontaneous emission. Calling this a "maser" is not completely unprecedented. As I noted below, x-ray lasers operate on the same principle: they have no resonant cavity, and hence are not technically "lasers", but researchers in the field never call them by any other name.
Anyway, feel free to tinker with the page and try to improve it. You can always explain your rationale here if you like, or propose a change first here if you are unsure about it.--Srleffler 04:10, 5 December 2005 (UTC)
Hi it seem that I can not edit any page now. Am I blocked ? Alain Michaud 03:23, 14 December 2005 (UTC)

Looks like you got through here. May be a temporary problem with the interface. You may give it a half hour or so. Also, you can sign your talk entries with four tildes (~) - see [1]. Cypa 03:31, 14 December 2005 (UTC)

Finally I got it through! I typed my comments about 5 times over the last week... Finally there was a page to tell that the server was down!

  • I like the idea of having a section or page labeled: "maser (astronomy)". Great! In fact we could also have "maser (oscillator)" and "maser(amplifier)".
  • You are right: "maser" is used a lot in astronomy! I think myself that this an abuse of the language, but we have discussed this topic enough now. Finished...
  • I have a picture of a maser, but I want to be sure of the legal (copyright) aspect first. I am thinking about it...
  • I have changed one line to better describe the picture. It does not represent a maser, but an Hydrogen discharge inside a maser. This is a small change.
  • I am planing to draw a small sketch of an hydrogen maser. This will take some time however... but I will do it for sure.

Cheers

Alain Michaud 23:30, 14 December 2005 (UTC)

[edit] Basov and Prokhorov

To quote the article:

Theoretically, reflecting principles previously discussed by Joseph Weber at the June 1952 conference of the Institute of Radio Engineers[1], the principle of the maser was described by Nikolay Basov and Alexander Prokhorov from Lebedev Institute of Physics at an All-Union Conference on Radio-Spectroscopy held by USSR Academy of Sciences in May 1952.

May 1952 comes before June 1952, so how can June be "previously"?

Giant Crab 03:22, 30 December 2006 (UTC)

They independently discovered the maser nearly the same time. I've done appropriate addition. My sources were [2],[3], [4]. Cmapm 16:12, 15 Mar 2005 (UTC)

As far as I know, there are masers, such as the dual nobel gas maser, which work in the VHF range of the spectrum. So, a maser is 'not' just a microwave laser.

[edit] "Molecular amplification"

The statement that "Because of this, the acronym has been appended in the current usage, and is usually taken to stand for "molecular amplification by stimulated emission of radiation" [1]. Under this defintion, an optical laser is a specific type of the more general maser." is preposterous. The term maser is virtually never taken to mean "molecular amplification by stimulated emission of radiation". It appears on an acronym list which is repeated in different languages and therefore gets 20 hits [5] on google. It appears NOWHERE in a scitation search and so far as I can see appears on not one single scientific site in the google search. It is ludicrous to claim it is being commonly used this way. Stop trying to change definitions of terms. That is not what wikipedia does. --Deglr6328 00:07, 17 July 2005 (UTC)

Yeah, well I found more than that in scitation, so I don't know what your searching, but anyway, the term maser is used implictly almost always. That's because people who do theory and work on masers these days understand that the principle behind a certain type of maser can be extended to many different atomic\molecular species, so that you could get radio, microwave, light, etc., just by changing the parameter space. So it's just understood. Also, did you do a full text search? Obviously nobody would put such a definition in the title or abstract. The problem that it doesn't come up in google is what we are trying to remedy. There is alot of confusion being generated by out of date definitions. It really is common usage in those in the maser field. They tend to take as given that a maser does not refer specifically to microwave. Cypa 01:04, 17 July 2005 (UTC)

Scitation (full) search for "raser": 1. Morphogen Gradient from a Noisy Source Jeremy L. England and John Cardy Phys. Rev. Lett. 94, 078101 (2005) PDF (118 kB) GZipped PS Order Document


2. Condition for generation of radiation in rasers Yu. M. Seidov, É. M. Shakhverdiev, and I. I. Abbasov Tech. Phys. 42, 1238 (1997) PDF (53 kB) GZipped PS Order Document


3. RASER millimeter-wave-radar testbed John R. Walker, Jr., Darryl G. Huddleston, Keith D. Trott, and Pope P. Britt Proc. SPIE Int. Soc. Opt. Eng. 1874, 140 (1993) PDF (331 kB) GZipped PS Order Document

One and three are irrelevant, they do not refer to stimulated emission of radiation in any way. Hence, one single relevant hit. --Deglr6328 01:44, 17 July 2005 (UTC)

That's true. If you use other search engines you will find more. Also, I think the full search on scitation only includes full "field" searches, where the fields are abstracts, subjects, titles, headings, etc. Cypa 15:40, 19 July 2005 (UTC)


So would you like to present any actual evidence whatsoever to support the now incessantly (and redundantly) repeated claim in the article that "molecular amplification by stimulated emission of radiation" is 'now the modern commonly accepted term' other than the fact that you alone reaaaly want it to become that? --Deglr6328 07:08, 21 July 2005 (UTC)
Oh Deglr6328, it has nothing to do with what I want. The page is an attempt to explain, in a consistent and coherent way, the modern usage. It says, in the modern sense "may" be taken to mean, etc. I put the qualifying auxillary verb in just for you, where it seems obvious to me and everyone else I've spoken to what is meant. Anyway, you cetrtainly haven't offered any alternatives at all, and I think the page in its current instantiation is certainly more informative than it was. In fact, you seem to have some serious hubris built in to some notion of being the measure of good science; and while I appreciate your intent, I think you are not well enough informed on this subject. Either that, or your inability to compromise has rendered your approach caricature-esque at best.
But then, maybe I'm living in the past. What is your suggestion? As far as references go, again, I would recommend the three given below (as I did before). Mostly I would recommend reading more of the literature from the maser community in general. And again, I would ask any bystanders for there input. The idea is to reach the most applicable consensus, and that being the case, it is possible that my perspective does not represent that.
Below is the discussion that was had on the laser page for those of you who feel lost. 128.62.97.227 15:51, 21 July 2005 (UTC)
I see handwaving but no real answer. Submitted to RFC. Also there is no need to copy a whole talk page here. For those interested in seeing a previous discussion see Talk:Laser.--Deglr6328 06:31, 22 July 2005 (UTC)
Okay, maybe someone will comment. But if you could, what type of response are you looking for? I've given references, and I've explained how maser is used which is inconsistent with the "micro-aser" acronym; the references also cite this; and the new acronym is referenced and explained (in a reference at least once by a nobel prize winning physicist over 40 years ago. Further, I've personally talked to people in my department in physics and chemistry. So what is it that you want: a scribe from the pope:)? Seriously, what do you expect at this point? I understand that in your part of the world this acronym is unambiguous; but that is not the case evrrywhere; which seems fairly obvious due to the references mentioned above and the explicit explanation I gave in the talk page and in the terminology section of the maser page (in the laser talk page Talk:Laser). "Hand-waving," as far as I've understood it, is when an asserion is made without any evidence or logically stable explanation. How this applies here is baffling to me (and then, how could any of the other arguments you've had on the Talk:Laser page be anything but handwaving?). I guess you feel the more appropriate option is to ingore the fact that anyone uses "molecular-aser" or that it is meant implicitly in a number of theoretical texts (see ref)? 128.62.97.227 14:35, 22 July 2005 (UTC)

[edit] Molecular Amplif. would be a retronym, is not the original usage for Maser.

I propose the following in the lead before the TOC:

"More rarely, the term maser can also be taken to mean the more general "molecular amplification by stimulated emission of radiation". However, the original definition was clearly for microwave radiation. [6] Under this definition, an optical laser is a specific type of the more general maser (see below for details). It was not until Theodore Maiman's successful approach to laser operation, using a ruby crystal, that light-wave frequencies were generated."

That should show that the role of the cavity resonator was the pivotal insight by Maiman. Ancheta Wis 02:22, 30 July 2005 (UTC)


This statement above, as it is, doesn't make much sense to me. Where does this sentence fit in: "It was not until Theodore Maiman's successful approach to laser operation, using a ruby crystal, that light-wave frequencies were generated." I would think this should go under the history section? Perhaps adjusting the sentence to "more rarely," would be appropriate, except for the fact that most the lit. that I've read in the last 10 years has been on masers in the radio frequency range; which would imply the that molecular maser acronym would be the more common. Therefore, instead of making a wrong statement, perhaps we should stay with the weaker statment - As far as I can see, the current article is clearer than the proposed revision at this point, and how Theodore MAiman fits in remains unclear. Perhaps his contributions more naturally belong in the laser article. Cypa 17:49, 30 July 2005 (UTC)

From what I see, the existence of the alternate acronym ("molecular") has been demonstrated, but this isn't what's in question. "Molecular amplification by stimulated emission of radiation" (with quotes) yields 33, while the same with "microwave" (and still in quotes) yields 4,210. It's clear to me, at least, that the common usage is overwhelmingly microwave. siafu 13:40, 9 August 2005 (UTC)

There's no question that you're right on a google search. In addition, if we are to include the astronomy and astrophysics publications in the last 10 years or so, then again, the usage of the "microwave" acronym is definitely most common by percentage. However, and this remains a weak (unvarified) predicate, but if you restrict yourself to physics/engineering/optics papers in the last ten years (not including the astro papers), you might find that "molecular" is the more common; implicitely. This seems to be what I've observed. However, trying to quantify this is actually a bit of a task, so it is possible that the statement is predicated on a false assumption. Cypa 01:49, 14 August 2005 (UTC)

I just wanted to point out that in laser physics, the term "optical maser" is obsolete, having only been used AFAIK for a while in the sixties (e.g. by Townes in his Nobel prize lecture). Within the laser physics field, a "maser" is always a microwave device, and laser is the generic term when one is needed, in that microwaves are a form of light (part of the electromagnetic spectrum). A maser is a type of laser, not the other way around. It's possible that this is simply a difference in terminology between the maser and laser research communities, but I haven't seen anyone promoting this point of view other than Cypa. --Srleffler 22:17, 17 October 2005 (UTC)

Given that masers were invented first (1953 vs. 1960), it's not surprising that there's an argument against masers just being considered a "type of laser" (technically they're both "types" of the same thing at equal levels). siafu 22:22, 17 October 2005 (UTC)
I wonder if the best compromise might be to assert that the modern definition is "molecular...", but that the term 'maser' is only used when speaking of devices below something like 1 THz. Devices above this are pretty much universally referred to as lasers, at least by those of us who work with them. Cypa's main argument seems to be that radio-frequency stimulated emission oscillators are called 'masers', even when they emit outside the microwave band. I don't dispute that. I would be comfortable with text that reflects the common usage of 'maser' for devices below some (possibly vague) cutoff, and 'laser' above, without asserting that either is the generic term.
There may be some technical reasons for this difference in usage too. I wonder if microwave and other radio-frequency 'masers' are more similar to one another engineering-wise than they are to optical lasers. Lasers in the visible, infrared, and ultra-violet have a lot in common. They typically use an open cavity bounded at two ends by mirrors, and use optical components within the cavity and outside to focus the beam, etc. I'm guessing masers typically use a closed cavity, and that the devices used to manipulate the beam don't bear much relation to the kind of optics with which I am familiar.
Cypa, if you're still around: Do you have any references to usage of the term 'maser' to refer to devices above about 1 THz that are more recent than, say, 1985? I know Townes and some other early workers in the field referred to "optical masers", but that usage is now obsolete in laser physics. I would like to figure out whether this is just a disagreement about what the commonly used term is for the generic type of device, or whether there is actually a disagreement in common usage about how one would describe *asers above ~1 THz. --Srleffler 23:52, 17 October 2005 (UTC)

Yeah, I haven't seen any papers that refer to masers above the microwave region, and I think your right about the technical difference, to some extent. Anyway, I think the compromise sounds quite valid. The article should clearly state that masers usually refer to rf and microwave -asers, but that due to an endeaver towards consistent terminology and the acronym of Townes', the definition seems to imply lasers. Does that work? You can word it differently if it seems non-neutral in the point of view. My only goal in writing out the terminology was so that others who found the terminology as confusing as I had, could quickly reference the article and find a coherent explanation. But do as you think best. I tend to prefer erring on the side of more information :). Cypa 00:10, 18 October 2005 (UTC)

OK, I took a shot at it. See what you think. If you think it's generally OK, remove the NPOV tags. If not, make or suggest some changes and we'll see if we can make it work. I tried to keep the information content while smoothing over the terminology dispute. I did compress some sections to make it easier to understand (I hope)--Srleffler 05:45, 18 October 2005 (UTC)

[edit] Microwave vs Molecular

What is written on the page right now in not wrong. But I think that "M" is for microwave:

1 - I do not know where "Molecular" came from... May be there were some papers with "molecular", but this was an error! This was before the "laser". some of those molecules would emit in the MHz range and "maser" was a nice word. It was then easy to reuse the word.

2 - TODAY, the only type of microwave device that you can buy is the (atomic) Hydrogen Maser (no molecules!).

3 - The vast majority of papers reporting the so called "xx-maser" where XX is a molecule were in fact trying to demonstrate that they had seen some emission. The term: stimulated emission would have been more appropriate. (Authors always try to use modern words!)

All the physical principles and techniques of the maser were known long before the Townes experiment! He described the maser as a device that would have: i) population inversion (stimulated emission), ii) a resonator (feedback), iii) would oscillate (gain larger than relaxation). It is the combination of those elements that gives the character of the maser. For example, I do not think that the term maser should be used if the device does not produce an oscillation. One would use instead the terms: "maser amplifier", "maser operating below threshold", "passive maser" or "frequency standard".

Alain Michaud 06:32, 4 December 2005 (UTC)

I agree with you that technically devices that do not include a resonator should not be considered to be lasers or masers. Current usage in the scientific literature does not strictly hold to this, however. It's relatively common for superradiant stimulated emission to be referred to as lasing/masing, even by experts in laser physics. (See x-ray laser, below.) Note that, by design, Wikipedia reports on things and does not attempt to influence them. The article can explain why these cases are not technically lasers or masers, but should not attempt to convince anyone to change current scientific terminology.
The fact that only hydrogen masers can be bought commercially is not very relevant. Other types of maser can be and have been made in the lab. I don't know if any are still used for research, but it would not be wise to assume that other types of maser are not used, just because you can't order one from a catalog.
I don't know where the "molecular" acronym came from either, and it may be incorrect but that needs to be judged by someone with more expertise in the field. Note, though, that the original "microwave" doesn't work either—it has become common to use "maser" to refer to systems that emit in the RF spectrum. I think the current text nicely covers the uncertainty and ambiguity in this issue.--Srleffler 07:43, 4 December 2005 (UTC)

[edit] Naming, again

I have been reading more on the early history of the laser, particularly Taylor's biography of Gordon Gould (referenced there). It appears that the usage of "laser" vs. "optical maser" is completely intertwined with the patent fight (and fight for recognition) between Gould and Townes. Townes and his colleagues continued using "optical maser" long after the rest of the scientific community had adopted Gould's terminology, in part because they were still fighting with Gould over who deserved the credit (and the patent) for the invention. When I have some time, I will edit this article to reduce the emphasis on "optical maser" and "molecular amplification of...". These are obsolete terms that really only deserve a brief mention in the context of the history of the field.--Srleffler 21:43, 29 September 2006 (UTC)

[edit] X-ray lasers

If there are light and microwave -asers surely it is possible to create a xaser or raser, no!? x-ray or radio, or any other spectrum of electromagnetism - aser?? Thoughts?

Yes, In principle you can get coherent radiation anywhere you get spontaneous radiation, providing: i) you have a sufficient feedback mechanism through a resonator (two mirrors for example), ii) you create a population inversion, as the source of energy.
Those two conditions become more difficult to attain at higher frequencies. Optical pumping which is sometimes used to create population inversion requires some light which is at a lower wavelength: for example the light from a "blue" laser can pump a "red" laser but not the opposite. What would you use then to pump a blue laser? Alain Michaud 05:37, 4 December 2005 (UTC)
X-ray lasers have in fact been made. The most famous type was pumped by a nuclear explosion. (Really.) Obviously, it is a one-shot device. Laboratory-scale X-ray lasers have been made at Livermore and Princeton. These were pumped by very intense laser pulses, strong enough to ionize the lasing medium and excite the ions into an excited state despite the pump light being of lower frequency than the x-rays. These have been used for plasma diagnostics and for imaging. While these are universally referred to as x-ray lasers, they are not true lasers because they lack a resonant cavity. Technically, they are supperradiant emission devices. It's very hard to make good mirrors for x-rays, but if you have enough gain you can get stimulated emission without a resonant cavity. See [[7]] for an article on x-ray lasers.--Srleffler 07:22, 4 December 2005 (UTC)

[edit] Ottowa?

What is an "Ottowa conference"? Is this a misspelled reference to the Canadian capital, Ottawa?

This is Ottawa. I have added the link.
Alain Michaud 05:53, 26 February 2006 (UTC)
Weber's obituary[8] does mention that he gave a talk on quantum electronics "in a June 1951 meeting of the American Physical Society." His other online obituary[9] says
He presented his ideas in a talk at the June 1952 conference of the Institute of Radio Engineers in Ottawa, Canada, and published the first open-literature paper on what is now called quantum electronics. His efforts were acknowledged by the IRE when they awarded him a fellowship (in 1958) "for his early recognition of concepts leading to the maser." The development of operating maser and laser devices was achieved by Charles Townes, Nikolai Basov, Aleksandre Prokhorov, Theodore Maiman, and Arthur Schawlow."
--Srleffler 06:03, 26 February 2006 (UTC)

[edit] Crop circles

Masers are said to be one of the most plausable ways intricate crop circles have been created, be it by army tests or whatever (I'm not interested in that). I think it should have some side mention in this article. └ VodkaJazz/talk┐ 21:00, 17 April 2006 (UTC)

Sorry, but this is trash. Masers would not actually be useful for creating crop circles. Actually, the most plausible way of creating crop circles is with sticks and string. This has been demonstrated many times. The guys who made the first crop circles showed the press how they did it years ago.--Srleffler 00:41, 18 April 2006 (UTC)
Agree about the use of masers in crop circle formation, but from all the crop circles that continue to pop up, if these are being made exclusively by people with sticks and rope then there is an entire unnoticed international hobbyist subculture comparable to Ham radio that has gone mainly unnoticed for decades. Mike 05:11, 3 October 2006 (UTC)
This is close to the information I was seeking: A kilowatt device with a cavity which is pumped by intense sunlight to produce coherent microwaves or millimeter waves. What else might it be named other than maser which seems to be a nanowatt device? Ccpoodle 22:15, 31 October 2007 (UTC)

[edit] Science Fiction?

Should I include Gundam X in that section? Gundam X uses a MASER to deliver energy to its Satellite Cannon. Or is that theoretically possible? (In which case it SHOULDN'T be included?) -Izaak

Probably not. Appearances of masers in science fiction are not that important in the context of an article on real masers. Only the most prominent examples should be included.--Srleffler 21:32, 29 September 2006 (UTC)

[edit] Stability

The Hydrogen Maser section notes that "The frequency of the signal is fixed but extremely stable." I assume that this is why it's useful as a time reference. But I would like to know why other masers may not be so stable. What mechanism would lead to a drift in the frequency? Thanks!

John Y (talk) 08:36, 1 May 2008 (UTC)