Talk:Distributed Bragg reflector

message: Dopeydog,
Is it correct, the reflectivity formula is for the center wavelength of the stopband?
Also, the graph often loses detail (for example, all of the text and lines) when scaled. This seems to depend on the browser, screen resolution, etc. Can your program produce a black-on-white version? (I'm assuming you're the "Me" who submitted the graph).
--The Photon 05:07, 14 August 2006 (UTC)
replies: text: I may have confused matters with my edit. The formula for bandwidth used several variables which were not defined in the article. I took my best guess as to what he intended. (Note to Dopeydog: In Wikipedia, as in academic writing, always define even the most trivial of variables. You may not assume that the reader knows what you mean by \lambda, \nu, etc.)--Srleffler 05:22, 14 August 2006 (UTC)
thread_title: Reflectivity

message: this page seems to be focusing solely on the optical side of things, there's a different formula for corrugated metal waveguides determining the central frequency of refelection.
also i edited the bit at the end just to include free electron masers as these mirrors are excellent in such devices.—Preceding unsigned comment added by  Hermanzegerman (talk • contribs) 05:22, March 1, 2007
:I'm not familiar with these corrugated metal waveguides. Are they still "distributed Bragg reflectors"?--Srleffler 13:12, 1 March 2007 (UTC)
replies: text: Definately, they still have Bragg reflecting devices distributed across their surface. There's lots of papers on coaxial, cylindrical and planar DBRs in FELs, Gyratrons and the like. They're big RF pulsed power devices popular in Russia and China for their potential in directed energy systems.Barryferguson6 11:13, 4 September 2007 (UTC)
thread_title: Non optical

message: The high-quality note was removed.  This is unfortunate, as it is an important characteristic of such devices.  These mirrors can have reflectivities (in the appropriate band) much closer to 100% than a metal mirror.--Torsionalmetric (talk) 19:36, 4 May 2009 (UTC)
replies: text: Metal mirrors are not exactly state of the art. DBRs are not better reflectors than modern dielectric mirrors. I removed it, though, because "high quality" is vague. If the assertion was that they have unusually high reflectance, the article should have said so. If there is some specific and unambiguous way that DBRs can be said to have higher quality than other reflectors, I would be open to trying to work that back in.--Srleffler (talk) 00:46, 5 May 2009 (UTC)
replies: text: Ahhhh, my apologies.  I was confusing DBRs and modern dielectrics.  Should some words be added to the first paragraph that they are a derivative or precursor to modern dielectrics?  138.210.84.242 (talk) 17:44, 5 May 2009 (UTC)
replies: text: I'm not sure how best to characterize the distinction between a DBR and a dielectric mirror, except of course that DBRs are used in waveguides and "dielectric mirrors" are used in free space. They operate on similar principles, although the designs are different in practice. I'm not sure if they are best characterized as two names for the same thing, completely distinct things (by some definition), or overlapping. I have the impression that DBRs use layers that are exactly a quarter wavelength thick, while thin film dielectric mirrors use coatings whose layer thicknesses are numerically optimized to produce the desired coating curve. --Srleffler (talk) 22:37, 5 May 2009 (UTC)
thread_title: High-quality

message: In my opinion, there's no reasons to have dielectric mirror and distributed bragg reflector in different articles. it's 100% the same underlying pysical principle. Dielectric mirrors are a used of Bragg interference effect to create mirrors "in free space" in general, whereas DBR are more often heard of for laser cavity mirrors, but they are the same, and it would nice reorganizing a bit all this, what is your opinion ?Matthieu.berthome (talk) 07:19, 3 July 2009 (UTC)
replies: text: I would rather not merge these two. DBRs are used in fibers and other waveguides, while dielectric mirrors are used for free-space mirrors (i.e. at the boundary between a substrate medium and air). While the underlying physics is the same, they are distinct technologies. I am not even sure that they are the same, aside from that. See above: I believe DBRs use many layers of exactly quarter-wave thickness, while dielectric mirrors typically do not.--Srleffler (talk) 20:13, 3 July 2009 (UTC)

text: If merging, then merge the two articles as "distributed bragg reflectors" as DBRs not always consist of dielectrics, but also often of semiconductor material. Therefore, describing the mechanism without restricting to dielectrics would be better, i guess. A pure explanation based on index contrast will hold! 134.102.20.212 (talk) 14:15, 20 January 2010 (UTC)
thread_title: Merger_proposal