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Thread: Frequency doubling into the yellow

  1. #41
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    Quote Originally Posted by mixedgas View Post
    The one I measured was 561.1 nm and a weak peak about 561.3 nm, two closely related lines lasing across the gain bandwidth. . Remember 561 is a broad transition, with about +/= 0.6 nm wide gain bandwidth.
    I bought one, kept it for two weeks, and sold it to a friend who needed it more then I do.

    There are four laser laser lines in that upper manifold: 1123.4, 1123 nm, 1116 nm, and 1112 nm, so 560.5, 561/2 558.0, 556.5 center wavelengths with a +/= 0.3 nm bandwidth are possible

    Steve

    I guess this depends what crystal is used. From the information I have found from two universities ND:SFAP produces 565nm.

    Also, the bandwidth on this laser is very wide. On my Spectrometer it's about a 6nm bandwidth. It seems like a rough crystal. But it does work.

  2. #42
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    It shifts around a bit with temperature. When warm it moves 561 ish but when cold back 565 ish. Must be the pump diode floating around. Anyway I Like it. I however am going for the 575nm jobs and am in line. If these really are 30.00. I'll get a bunch and pbs /edge a few. for my lumia the size of the beam doesn't much matter. Now that said I wonder if I can add a line to my rgb and use the multiline output from LD2000 to make a stellar white out of this. Bet I'll need an AOM for it though and power will be low. Still. Crisp as all get out white!

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    Just to clarify, the laser that Steve and Marc have been discussing (the e-bay link) is a low-power, DPSS design, right?

    Because the one that Daniel Briggs posted (including the link to the AC Lasers Facebook post) is an OPSL design. So much greater output power, superior modulation, and very good beam specs, but also a few more zeros in the price!

    Adam

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    Quote Originally Posted by buffo View Post
    Just to clarify, the laser that Steve and Marc have been discussing (the e-bay link) is a low-power, DPSS design, right?

    Because the one that Daniel Briggs posted (including the link to the AC Lasers Facebook post) is an OPSL design. So much greater output power, superior modulation, and very good beam specs, but also a few more zeros in the price!

    Adam
    it looks dpss to me and is about 40mw. I have one in hand 565 and three 575 coming. None are opsl. Not at these prices. They are perfect for my lumia. Not sure about modulation.

    this may be Raman based gain medium
    Last edited by kecked; 05-19-2018 at 18:02.

  5. #45
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    Quote Originally Posted by buffo View Post
    Just to clarify, the laser that Steve and Marc have been discussing (the e-bay link) is a low-power, DPSS design, right?

    Because the one that Daniel Briggs posted (including the link to the AC Lasers Facebook post) is an OPSL design. So much greater output power, superior modulation, and very good beam specs, but also a few more zeros in the price!

    Adam

    The low powered (and low cost! ) ones are DPSS.

    We have quite a few higher powered (several watts) OPSL in 577nm and 480nm, but these still have the "traditional" price tag
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  7. #47
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    Feel like I want to revive this thread.
    I heard people said newer batches of the product had a poor lifespan and efficiency. (the chinese low powered yellow dpss modules)

    I wanted to buy one but 50mw is very little power.. even when you'd combine 2 you'd be looking at 100mw (with added instabilities the more you stack)
    Say you'd buy a bunch and stack them up using a knife edge.. use aom for modulation then if you can keep the power fairly stable across then its still "perhaps" worth while
    Has there been any more developments on this?

    I secretly was hoping for their engineers to make a more powerfull version but it's clear they weren't able to.
    How did they manage to make it so low cost? If they could do it then surely someone else could do it too.. but perhaps tackle the bottlenecks of the design one by one.

  8. #48
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    Quote Originally Posted by masterpj View Post
    Feel like I want to revive this thread.
    I heard people said newer batches of the product had a poor lifespan and efficiency. (the chinese low powered yellow dpss modules)

    I wanted to buy one but 50mw is very little power.. even when you'd combine 2 you'd be looking at 100mw (with added instabilities the more you stack)
    Say you'd buy a bunch and stack them up using a knife edge.. use aom for modulation then if you can keep the power fairly stable across then its still "perhaps" worth while
    Has there been any more developments on this?

    I secretly was hoping for their engineers to make a more powerfull version but it's clear they weren't able to.
    How did they manage to make it so low cost? If they could do it then surely someone else could do it too.. but perhaps tackle the bottlenecks of the design one by one.
    The material itself has ion migration and defect problems at the atomic level, varies from boule to boule and location to location in the boule. At least in the units that I examined and own. This is mentioned in scientific papers on the material.
    Considering a Boule takes months to grow, that leaves the problems to the academics in crystallography and the crystal growth factory to solve. Given the demand for five Watt medical lasers at this wavelength, I'm sure, funding permitted, some one is looking at the problem. There is not much wrong with the laser design itself. The crystals on the market were probably from one boule from a PhD student's graduate research project, and thus may/may not be grown again. Such is the nature of new laser development.
    ~
    The funding was possibly from a one-off government research grant. On such grants the end product usually gets disposed of as the degree granting institution sees fit, world wide. In China that means if the newly graduated student gets hired at XYZ Laser, the crystal stock goes to XYZ Laser.
    ~
    Hate to dash your hopes, but I'm guessing a single crystal growth cycle is 30K USD in cost. One LFPer works at said type of facility (In the US) part time, and his employer's chief scientist said "Interesting, but Too risky to dedicate a growth machine to this for months.".

    ~

    Steve
    Last edited by mixedgas; 07-22-2020 at 08:48.
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  9. #49
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    Do you have more information about these boules and their growing processes?
    even if it takes a month to grow.. if it's done in mass and little attention is required during the process of growing there is an opening there to push a cost down.

    How come so little people grow it if the demand is there? I feel like maybe the market for yellow is just too low to justify the jump for larger businesess.
    Is this growing of these crystals something that's viable in a home setup despite the slow growing time? Or is it impossible and we just have to hope someone can figure out a process to grow these crystals faster (so bigger cuts can be justified)

  10. #50
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    Quote Originally Posted by masterpj View Post
    Do you have more information about these boules and their growing processes?
    even if it takes a month to grow.. if it's done in mass and little attention is required during the process of growing there is an opening there to push a cost down.

    How come so little people grow it if the demand is there? I feel like maybe the market for yellow is just too low to justify the jump for larger businesess.
    Is this growing of these crystals something that's viable in a home setup despite the slow growing time? Or is it impossible and we just have to hope someone can figure out a process to grow these crystals faster (so bigger cuts can be justified)

    home...no! I’ve been chasing yellow for years. That 575nm line blew me away

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