Talk:Dye laser

message: There is a lot of information that should be included about this complicated topic. The toughest thing about building a dye laser is the speed at which the molecules change from a singlet state to a triplet state. Depending on the dye and solvent used, flash pumped lasers experience this change in roughly 1 to 2 microseconds. Also the lasing threshold is extremely high, further complicating the problem. (In plain English, the flash mush have an extremely short duration, and be able to bring the dye past threshold before useful fluorescence becomes useless phosphorescence, at which point the dye becomes partialy opaque, cutting off the beam.) Continuous wave lasers solve this problem by constantly pumping the dye at very high speeds. Further complicating the situation is thermal shock from the flashlamp, causing turbulent changes in the dye's refractive index. Dye cells and flashlamps are often encased in a water cooled pumping cavity, which helps absorb IR radiation before it can reach the dye.
Another complication is that liquid dyes are extremely high-gain/high-loss lasers. The beam only needs to make a few passes through the dye for high gains in power, (therefore, the output mirror is usually only about 80% reflective), but any reflections generated by the dye cell walls will dramatic sap power from the beam.
The "Construction" section, I think, should be relabeled the "Operation" section, and expanded upon. A section named "construction" should be added which summerizes the various types of dye lasers, including but not limited to: Flash Pumped Lasers, Axial Flash Pumped Lasers, Continuious Wave Lasers, and Ring Lasers. Also, an "Application" section should be added, since the applications for dye lases are often very specialize when compared to other lasers.
The "Chemical" section should be expanded upon to include solvents, and even some slight mention of flammiblity, corrosion, and health hazards. (Solvents are often extremely flammible and can be absorbed directly through the skin or inhaled vapors, and dyes, such as Rhodamine 590 chloride, can be extremely corrosive to all metals except stainless steel, whith "undetermined" health risks).
Last, the "Ultra-Short" section should also be expanded upon. (ie: Ultra short pulses are possilbe due to the dye's short fluorecence lifetime, but usually require the use of special "Negative Group Velocity Dispersion" mirrors, and such).
For some good references on the subject see: Design and Analysis of Flashlamp Systems for Pumping
Organic Dye Lasers – J. F. Holzrichter and A. L. Schawlow.
Annals of the New York Academy of Sciences, or Simmer-Enhanced Flashlamp Pumped Dye Laser – T.K. Yee,
B. Fan and T.K. Gustafson. Applied Optics – Vol. 18, No. 8 , or read the book "Principles of Lasers", by Orazio Svelto. More good info can be found at http://members.misty.com/don/xeguide.html#eg , or check out Sam's detailed website at http://www.repairfaq.org/sam/lasercdy.htm Zaereth (talk) 00:08, 14 November 2008 (UTC)
replies: text: I think you have a lot of good ideas. Why not be bold? I only don't think your comment that ultra-short pulses have to do with the dye fluorescence time is correct, but the rest seems OK. Han-Kwang (t) 11:19, 14 November 2008 (UTC)
replies: text: Thanks Han. You got me there. I've never constructed an ultra-fast laser, and so I'm probably mis-quoting something I once mis-read. I'll leave that section to people who have more experience on that subject. Give me a little time, and I'll work something up on the rest. I'm fairly new to Wikipedia. I've never made any changes to an article before. Are there any guidelins on how to cite the references I've listed? I've also found a few other articles, especially the Xenon Flash Lamp article, which needs some fixing also. Zaereth (talk) 01:02, 15 November 2008 (UTC)
replies: text: For ultrashort pulses you need a large bandwidth, which I think the dye provides by coupling electronic transitions to vibrations. A side effect of the coupling might be that the fluorescence lifetime gets shorter, but a short fluorescence lifetime does not make it suitable for ultrashort pulses by itself. I'll leave general editing advice on your talk page. Han-Kwang (t) 09:11, 15 November 2008 (UTC)
thread_title:  This article could use a little clean up and clarification 

message: I have added the information discussed above, (except for the wrong ultra fast stuff). If there is any question or comment, please leave it here. Zaereth (talk) 02:11, 6 January 2009 (UTC)
thread_title:  Added information 

message: Moreover, the dye can be replaced by another type in order to generate an even broader range of wavelengths with the same laser, from the near-infrared to the near-ultraviolet, although this usually requires replacing other optical components in the laser as well.
What is the point of this remark? Should we view it as a further form of tunability, or just a way to take apart and rebuild a laser? 178.38.74.237 (talk) 18:40, 21 February 2015 (UTC)
replies: text: It's trying to make the point that you can change the laser dye and the mirrors and get a different wavelength tuning range. See this for example: . --Kkmurray (talk) 18:52, 21 February 2015 (UTC)
replies: text: Exactly. A typical dielectric mirror has about 25 nm or so of good reflectivity. Broadband dielectric mirrors can get up to 50 nm, so changing the mirrors is often needed just to cover the bandwidth of a single dye. (Extremely broadband mirrors can cover as much as 100 nm, but these are rare and expensive.) Of course, this is not necessarily the case with metal-coated mirrors, like silver. which can often cover the entire visual range, but the reflectivity is not quite as high as with dielectrics. Zaereth (talk) 02:45, 22 February 2015 (UTC)
thread_title:  Significance of replacing the dye? 

message: From Coumarin : Coumarin is also used as a gain medium in some dye lasers,[3][4][5]  — Preceding unsigned comment added by 91.155.19.68 (talk) 23:06, 16 April 2017 (UTC)
replies: text: This article mentions coumarin, as well as fluorescein, malachite green, and others, in the chemicals section. It could use more information, but rhodamines are by far the most widely used examples in many sources, so they are easier to find. (We didn't intentionally try to focus so much on it, but the sources seem to use it often too.) For the most part, they are all very similar in operation and behavior. Dyes toward the blue end of the spectrum tend to have shorter lifetimes than dyes near the red, but all-in-all they are very similar. Zaereth (talk) 23:16, 1 May 2017 (UTC)
thread_title: missing info