ok, 532nm DPSS laser "lasing medium is- "Nd:Yag"
what is the "lasing medium" for 635nm and 473??
im filling out another variance and not too sure what to put here...
-Marc
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ok, 532nm DPSS laser "lasing medium is- "Nd:Yag"
what is the "lasing medium" for 635nm and 473??
im filling out another variance and not too sure what to put here...
-Marc
KNBO3 for 473nm
on the red, its direct injection so you will need to find a technical term for the reds lens maybe. I could be way off here but this is what i am thinking.
DPSS lasers operate by frequency doubling infrared light which is created by the excitation of ND ions within a host material. The host can vary greatly but the most common ones are YAG (yttritium aluminium garnate) or for our 'little' greens & blues more traditionally Yv04 (aka vanadate - yttrium orthovanadate)
Its the ND (Neodymium) that actually lases and like most materials has a number of laser transmission lines. The strongest is 1064 which doubles to 532 but lines at 914, 946, 1112, and 1342 are also used to create frequency doubled visible light at 457, 473, 556 and 671 respectively.
They are all pumped using 808nm light - again in our case, and most commonly these days by the use of high powered laser diodes or arrays. To create different wavelenghths the Vanadate is coated to promote the line needed and surpress the other lines. So for a 473 nm blue laser you would coat the xtal so that it will not reflect the 808 pump light, and will reflect 946nm and 473nm so that an optical cavity can be formed. Also the coatings will need to transmit the other ir lines so that a cavity that amplifies these wavelengths cannot be created.
The KNBO3 that DB refered to is actually the nonlinear freqency doubling crystal. there are a number of different materials used for this purpose and others include LBO and KTP (most common in green lasers). These are often chosen using their effeciency and tolerance to damage as well as cost in the selection process.
As DB said 635 is direct injection - meaning there is a single semiconductor chip that forms a tiny optical cavity and path to generate red visible light.
Bluray is also a direct injection device (and blue di diodes go up almost to 460nm) but as yet nobody had designed the technology to create wavelengths much in between using direct injection.
Im sure it will happen in time. We just need the end use to be desired enough for the research to be funded - maybe this will come on the bcak of all this laser TV talk that seems so hot at the moment.
Rob
Hey Marc -Quote:
Originally Posted by gottaluvlasers
Umm, no disrespect, here, but I doubt your 532nm DPSS is using Nd:YAG for its' lasing medium - unless it is producing over 5 Watts of Green, like 7W - 60W, which I am guessing it's NOT, am I right? :D
The label (if it is correct) on your green laser head should tell you the medium - if it says Nd:YAG, and is producing less than 5W of green, it is most likely actually using Neodymium-doped: 'Vanadate' (Nd:YVO4) and has the wrong sticker - here's a 'simple' article on why:
http://en.wikipedia.org/wiki/Nd:YAG_laser
http://en.wikipedia.org/wiki/Neodymi..._orthovanadate
...And as far as the 635, that should be a straight-up "semiconductor diode-laser" - yes, the 'lasing medium' is the semiconductor, but for purposes of your 'variance', you can just say "Diode Laser @ 635nm" - you don't need to get too technical with the CDRH - they'll 'get it' :D -
In fact, it is better to BE a bit 'broader', rather than SO specific - I am not suggesting you OMIT, but rather INCLUDE - say, "DPSS Nd:YAG and/or Nd:YVO4Laser @ 532nm; from (lowest mW you will use, ie: 100mW) to 5 Watts, max; Diode Laser @ 635 - 670nm from XmW to XmW..." (this way, you're not LIMITING your approval to ONLY EXACTLY WHAT you listed, cause that's what you'll get approval for: nothing more, nothing less...) ya dig? :cool:
You might also enjoy these articles:
http://en.wikipedia.org/wiki/Diode-p...id-state_laser
http://en.wikipedia.org/wiki/Laser_diode
(helps clean up those 'dust bunnies' about the differences between diode lasers and DPSS lasers...;))
Anything else, you've got my number, dude...
ciao
- J
*sigh* - Note to self: always remember to refresh BEFORE you post!!!! :rolleyes:Quote:
Originally Posted by stanwax
(good job Rob...) - hey, I'm a poet and didn't know it! :D (sorry..)
peace...
- J
Jon - at least you did answer his question - which im not sure all my babble achieved!Quote:
Originally Posted by dsli_jon
Rob
On the contrary Rob... I thought your reply was excellent. You covered the bases quite well. ;)Quote:
Originally Posted by stanwax
I do agree with Jon though; it would be better to be a little more broad in the definition to the CDRH, just so you aren't limited later on.
Great info though.
Adam
Well adam & jon CDRH variance is something that you know infinitely more about than I do ;)
Rob
Hey Rob! -Quote:
Originally Posted by stanwax
Yeah, Marc just needed a bit of 'tuning' :D from both sides - 'technical' (diffs between xtals and WHY and diodes vs DPSS, etc) and 'practical' (how not to 'pigeon-hole yourself with a regulatory agency, like CDRH...) - so, yeah, nice 'PL-teamwork' mate! :) ...we gave 'im some of the 'book' and some of the 'street' :D ...I expect we should see a nice big THANKS from Marc shortly...:cool:
cheers...
- J
jon, buffo, stanwax, dreambeamz-
thank you YET AGAIN!!! this forum is DEF turning into a savior. being one of the newer companies for laser shows, its great to know alot of you "old skoolers" like helpin a brotha out! (oh, by old skool i dont mean "OLD"...lol...) ahem...anyway-
thanks for all the help you guys have been!!! hopefully one day i can return the favor.
oh and for the variance i put solid state DPSS argon @1.21 jiggawatts. thats correct right?? :) lol....
-Marc
Quote:
Originally Posted by gottaluvlasers
Hahaa... I'd say that definitely gives you some room to move around within your projector :D
lol...
well, i just remembered that its actually 1.44 jiggawatts. i pot modded the flux capacitor the other day after deciding to wanting to be able to light a match from 184 miles away (WITHOUT blackening the head!!)
:)
LOL...
-Marc
Marc - NO NO NO!!!! - it's 1.21 Zorgawatts!!! - they're gonna KNOW "jiggawatts" are from 'Back to The Future', silly! :D:D:DQuote:
Originally Posted by gottaluvlasers
Ps - you're welcome...;) like I said, anything else 'variance' you've got my #, bro...
ciao
- J
"What the hell is a jiggawatt!?!" ... Marty McFly, November 5th, 1955.
Yeah, I love that movie too!
Ok one more and then I'm done:
"Doc, all we need is a little Plutonium!"
"I'm sure in 1985 Plutonium is available at every corner drug store, but in 1955, it's a little hard to come by!"
Classic!
Adam
lol...
i think this thread is the very definition of ummmm..."going off topic!!" :) on that note, i see a thread in the "Lounge" section coming VERY shortly of movie quotes!!!
LOL...
thanks again guys for the help.
now back to our regularly scheduled program...
-Marc
So is the laser crystal (Nd) the most expensive part of the laser?
Or is it the diode or the optics, or the AR coatings?
Or perhaps the frequency doubling KTP?
So has Pu ever been used as a lasing medium?
Quote:
Originally Posted by Buffo
I dont think so, due to its toxicity in small quanities, but directly reactor pumped XE, AR, KR, and CO2 lasers have been built, yes, with the lasers in the reactor core. The noble gasses have big enough atomic cross sections that this works, and yes I can find the nasa publication cite for this if u dont believe me.Quote:
Originally Posted by nanoWatt
Steve
PS some NASA examples of your tax dollars at work. From the Nasa Reports Server: The reactor pumped hene is gonna have a hard time fitting in the bar code scanner. These were 4 outta say 100.
Nuclear excitation of CO2 and CO
Author(s): Jalufka, N. W.
Abstract: A technology assessment of CO2 and CO nuclear pumped laser experiments is presented.
NASA Center: Langley Research Center
Publication Year: 1979
Added to NTRS: 2006-08-03
Accession Number: 80N13447; Document ID: 19800005192
CW nuclear pumped lasing of 3He-Ne
Author(s): Carter, B. D.
Abstract: The results of a study on the CW nuclear pumped lasing of the He-Ne system are presented.
Preliminary experiments measured single pass gain for the 6328.2A laser transition at neutron fluxes up to 1 x 10 to the 14th power ...
NASA Center: NASA (non Center Specific)
Publication Year: 1979
Added to NTRS: 2006-08-03
Accession Number: 80N13442; Document ID: 19800005187
University of Illinois nuclear pumped laser program
Author(s): Miley, G. H.
Abstract: The development of nuclear pumped lasers with improved efficiency, energy storage capability, and UF6 volume pumping is reviewed. Results of nuclear pumped laser experiments using a TRIGA-type pulsed reactor are outlined.
NASA Center: NASA (non Center Specific)
Publication Year: 1979
Added to NTRS: 2006-08-03
Accession Number: 80N13444; Document ID: 19800005189
Nuclear pumped laser research at the Jet Propulsion Laboratory
Author(s): Russell, G. R.
Abstract: Using a partially nuclear excited xenon flashlamp to pump an iodine laser, laser pulse shapes were analyzed with and without nuclear flashlamp augmentation. The pulse shapes indicate that the deposition of nuclear energy is ...
NASA Center: Jet Propulsion Laboratory
Publication Year: 1979
Added to NTRS: 2006-08-03
diode lasers are just souped up leds really that just happen to produce laser light ( coherent and phased) by use of a quantum well thats depth is exactly that of the nm of the laser thats bieng produced (some however dont work like a green diode = damn hard and expensive) not that hard compared to making a CPU but the demand is tiny so cost is huge
as follows in next post
Dear Nanowatt, I am findng a YAG water cooled cavity is the most expensive component then the laser diode, and its driver current source, etc etc, many of the optical components even lenses and crystals($50-200) can be had for a fraction of their original mfg pricing on ebay.
The neodium is added in varying low percentages to the crystal it is not what the crystal is primarily composed of a glass such as Yttritium Aluminum Garnet. In higher power lasers percentages drop from several points to 0.6 percent. YAG can withstand higher power pumping than can Yttritium Ortho Vanadate YVO4
All barcode scanner uses infrared？Quote:
Originally Posted by mixedgas
What an amazing necro-post.
Robs post at #3 is actually a really good read, and shows just how far we/laser have come in the last 6 years!