Glad you're enjoying the channel! One day you will open a laser up, it's bound to happen eventually lol

Indeed, so many questions I have wondered for years and finally just getting to a point where I can understand and almost explain what's happening to a fundamental degree. To know what the parts do in practice is pretty simple, the inner workings of how these crystals are constructed and how they interact with photons is amazing. The technology is just going to get better and more available too, I can't wait to see OPSL hit the consumer market more.

​@@Zenodilodon Check out the OSRAM PL530, it's a low cost 530nm OPSL module that can produce 50 to 100mW of SLM output with many meters of coherence. Excellent beam quality too. You can buy the PL530 for about $50 on eBay (search "PL530") or the full RGB module (was used in pico projectors) for a little bit more. Uses optically pumped lithium niobate. It's basically like a very tiny Coherent Sapphire laser, so similar in fact that they licensed the patent from Coherent. Get one while you can, the projectors are discontinued and I'm sure OSRAM has a prohibitive MOQ.

@@dissahc I have a pair, one is already in a laser pointer build on this channel. They are amazing little units!

They are some fo the best 473nm laser to start with and at a great price when they are available. Styropyro posted up some information on how to optimize them and if you ever need assistance I can also help with that as well. They are certainly becoming a collector's item and IMO one of the best ways to spend $50!

@@Zenodilodon I haven't had time to get much into it for the past year, but my interests are leading me back in that direction. I also acquired a couple Jenlas D2.3's with 3W of 532. Each require 2V @20A. The 473 is a nicer wavelength though; wish I had one in the 500mW + range.

@@sylkelster Those Janlas sound skookum as frig! You may be able to find a spare 473nm resonator assembly and turn one into a really strong 473nm laser, it depends on the pump output configuration. I have here a 500mw 532 here I am thinking of converting over to a 200mw ish 473nm if possible. I don't know the condition of my spare resonator though. The LBO in the B&Ws can take more than 2 watts of pump power for sure if properly thermal regulated. The 500mw unit has a 5 watt pump. Styro got one of the stock B&Ws up to 80 mw from the 2 watt pump so 200mw from a 5 watt pump seems achievable. The green is pretty beat as it only does about 140mw currently so I have to check out the pump power before I tinker more with it. I tried to get it to run better with readjusting the resonator optics but no improvements. Tried another KTP and that was even worse. DPSS lasers are a lot of fun and a heck of a learning experience. I hope to do more with them and OPSL. If your interested in DPSS stuff I have a video up on a red DPSS laser you may enjoy!

Also, if you do laser stuff do post up some videos, I'd like to see more DPSS stuff myself and I am sure others would too.

@@sylkelster how much did you have to pay for those jenoptik 532nm lasers? Wouldn’t happen to be selling one would you?

The modified laser with the MCA containing the KTP is rather old, I should be getting more than 50 mw out of it from a 2.4 watt pump. I am unsure of how good the 2 crystals are, in addition to that it has a plastic collimating lens my thoughts are between those 2 the beam would be most terrible. It was rebuild 7 or so years ago when I got a few and learned the hard way the crystals where hydroscopic. I do have a crystal set from another resonator cavity laser that is for 532nm as well, it's not an MCA but I figure would handle better. I know exactly what you are talking about and I see them on some lasers when I lay a dichroic glass on some of my laser pointers, it's also common to lay the cover window on some DPSS lasers ( like the yellow I used in the video ) at an angle to prevent seeing this. I thought this was manufacturer fluke until I noticed the issue I had when making my own. If/when I get cleaner optics and newer crystals in I can see about getting you those interference rings, as stated before the optics in it currently are terrible if i am to be honest.

That's inaccurate, I have tested IR VS visible output with filters and an LPM. For more information on this check out the video I did on the shunt mod where I demonstrate this misconception with actual tests. CNI does indeed make some good stuff, I will agree with you on that. In cases where there is an IR filter on a laser it's most often to prevent IR from disrupting things like spectroscopy readings and not for eye safety. Very little IR escapes a dpss laser even without a final filter, a " 5mw " laser module tested 40mw, the IR wasn't even measurable even though the pump was 300mw inside. That's how little IR makes is through the DPSS crystals as the coatings on the crystals mostly the KTP already acts as an IR filter for the most part as it's purpose is to reflect IR back so it can be doubled in the KTP or other SHG/THG crystal.

​@@Zenodilodon -- We've measured it. We used IR cut filters that block everything past 710nm. These were for laser projectors with around 8 to 10 Watts in the visible spectrum. While significantly diverged, it can still present a hazard. Everything has to be factored when doing paperwork for variances to make the FDA happy. I'm thinking it was around 2005/2006. It would be a few years before Pangolin would make this process much easier with the Safety Scan Lens.

@@pmgodfrey Ah when working with such a large DPSS head like 10 watts final output I could see a watt or so leaking out, really depends on how good the optics are on the inside for SHG/THG. Still the IR leaving the laser head if properly running is the least of your concerns as it's still only a fraction of the output power in total. In some aspects it's good to see DPSS being phased out but the art is being lost, direct diode is not as clean, but OPSL is making a more common appearance especially in Kvant projectors. I think RGB laser systems is one of the few that still use high end DPSS for the green, 532 makes for some very clean oranges and yellows compared to direct diode 520nm. I feel you on the variances and paperwork, it's a huge reason I got out of doing light shows and started in with repairing things, companies like Laserwolf and Laser Energy get them re-certified after repair. Hopefully I will find myself doing repairs for Kvant/Pangolin soon right now it's up in the air, if not I'll work for LightspaceUSA. I don't intend to let the skills go to waste lol. Sounds like you know quite a bit and I welcome a chat any time!

@@Zenodilodon -- It wasn't like dozens of watts, I'm sorry if I made it sound like that in the beginning. Yeah, repairs are much more fun. :) I eventually left it behind to pursue other things but find myself wanting to get into it again. Every hobby I ever had, that I enjoyed AS a hobby became something I eventually made money at and that's when I started hating it.

@@pmgodfrey I hope that doesn't happen to me, I keep chasing the physics and don't ever really want to hit a wall in learning. It doesn't make much money for me yet, here and there a few good payouts but it usually gets eaten up in self investment and tooling. I fully understand now where you are coming from given the scope of the lasers, I somewhat agree that cheaper lasers can be measured over spec do to a lack of an IR filter but not by much. Much of of misconception on my end is in smaller modules, which ironically you often get more output than specified in the visible band like 5 mw often being 40 mw and ones rated for 100mw-150mw can easily exceed 200 mw. Up in the larger lasers the losses can pile up a bit more, it takes a heck of a lot of IR to make visible light, from what I have seen it's about a 10-1 ratio for larger DPSS units..

it's one of the CNI builds not sure what model exactly. It's the one more commonly found on eBay as it's what I had the discount code for at the time.

It's 589nm laser I believe, I want to get a 593nm eventually.

Zenodilodon is this your laser? Check out the host for the Aurora model. www.dragonlasers.com/yellow-laser-pointers.html

Nope, non-linear crystals are not the same as pump crystals and require a very careful alignment along the optical axis. Even in these Lasers just a slight hair small nudge could stop it from working by miss-aligning it. The other factor going into that is you need quite a lot of confined energy in the non-linear optic for it to start doubling.

@@Zenodilodon Thanks !

Also really wish I could’ve gotten a hold of one of these when they were still cheap. Now that guy on eBay is selling the lasers by themselves for $300 and up. Damn ridiculous.

@@hullinstruments That is a 594nm laser which in person looks like the yellow/goldenrod color in common road construction barricade flashers. There are several other yellows that use newer and cheaper self doubling crystals ranging in the 555-580nm range. I'll be doing a video on those this year. The 589/594nm lasers are typically expensive because of the manual labor in alignment and crystals, Mine was about $400.

When I get to taking apart a yellow/orange laser what color should I point parts out with? I am strongly thinking aquamarine :P

Ok ok ok ⚈ ̫ ⚈ could you please make a video showing all your different lasers ? That‘d be totally wicked!!! I like that in this video for example you’ve shown us its inner contents. And if you do decide to make a video, also please show us some unique diodes not just the common 5.6mm TO-18 package types

@@yasurikressh8325 I thought about it a bit back, however being in the industry I often end up fixing or getting lasers or exchanging them so quickly that to do a whole video as such would pretty quickly invalidate itself. So I am more so focusing in 2 directions repairs of lasers and products that contain them, and applicable knowledge videos such as this one. I think being able to devote a video to a single laser also gives me the opportunity to focus on explaining one laser well more then explaining many poorly. If I choose to do a video of a bunch of lasers I will let you know, I hope there to soon be an opportunity to jump into working on much more sophisticated stuff in future. To that extent this is only the beginning of what is to come and I am flipping excited, anymore so and I would have to stick a laser danger sticker on myself.

Zenodilodon I‘ll be patient then （。-＿- 。） Its just that its really interesting to find something new about lasers . Also since I dont have the kind of recourses its quite educating to find out about whats exists so I know what i can focus on. Like i totally want a blue dpss laser. I was thinking on getting a powerful 808nm pump diode and working myself up from there. Anyway thanks for this videos and thanks for replaying. I mean it!!

@@yasurikressh8325 I'll try not to let you down!

Mark, there are no pins that need to be jumpered that I know of. All of mine have fired up just using 5v to the laser driver. If you want to see if the laser is working at all you can open the lid and check for a dim red glow. This is IR up to 2W so be mindful of the danger if you start investigating further. If you see a dim red light inside that means that the pump is running and the laser should be on. If that is the case then you have an alignment issue. This is most often in the LBO which is held in the little copper block in the resonator held in with 2 screws. You can try to make slight adjustments to see if you can get the blue to start being generated. There is also often a foil shim under the copper block to set the angle of the crystal vertically, be very mindful of this possible shim being in place. I suggest if you choose to make adjustments to the LBO or any other optics to where dust free examination/lab gloves. I hope that helps!

@@Zenodilodon Cool, Thank you for the information.. I'll play with it and see what happens.. :)

The lasers are not collimated so you won't get a nice thin beam without a collimation lens. The output power and beam shape are related to the position of the LBO crystal in the resonator. I have had to readjust the LBO in many units to get them to perform well. You can also remove the front optical sensor to get a little more power out.

The temperature can vary, depending on the crystal's exact length. Have you removed your crystal at all from your laser? If you have or it has been removed before it could be out of alignment, these lasers to not have a correction for the up and down placement and often have to be shimmed under the block on one side. Realigning these lasers is very difficult to do in general. I have crystals here and I could probably align yours. Do you live in the US?

@@Zenodilodon i am in South Australia and no the laser stopped working and was inspected prior to the crystal being removed so i dont think it would be an alignment issue.

@@ruedogs Hmm, usually the crystal doesn't get damaged all to easily, more often than not the pump diodes goes. If the crystal was already removed I would so to carefully remove it and give it a visual inspection. If it looks good then try finding a position where it emits light without screwing it back down. Use a small pliers to hold the copper block. This will allow you to test it without a restricted axis in case it does need shimming. If you see damage on the crystal let me know. as far as testing the pump diode goes, this can be very hard without prior skill and tools as well. Sadly this is one of those things that if you have little to no experience in will be very hard to figure out, I have killed 3 in the process of learning about these myself.

@@Zenodilodon thankyou but yes as ive said the ir diode definatly is working and the crystal looks clearly cracked

@@ruedogs Well, hmm I do not know of a supplier myself for that particular crystal. On the upside if you choose to you can make a pretty decent green laser out of it easily if you're interested in that. I can send over pictures via e-mail on that. You're option otherwise is to wait and see if one of the SHG crystals ever get listed on eBay again.

For the DPSS it's probably going to be these make/model. It's a well known starter laser. Does your application need to be blue specifically? I don't know the bandwidth of the 473nm line, it looks pretty narrow given the speckle and was originally used in a spectrometer so I figure it's at least near SLM. Depending on how tight of a band you need there might be a SM diode that might suite your needs, though probably just on the cusp of good enough for things like holography.

@@Zenodilodon yeah i need a blue slm laser for full color holography. Blue is the most expensive for slm it seems, and id like more blue than 488 which is kind of more cyan. 488 are easy enough to find but this would be the perfect color

@@makkyd123 I have heard that the PLT5 450B is ok with holography. I can confirm first hand that it works for interferomertry pretty well. it's cheap enough to give it a try, I think HoloKidd has used them for full color holography. sites.google.com/site/dtrslasershop/home/diodes/osram-plp450-450nm-laser-diode

High powered blue DPSS Lasers are very hard to find and extremely expensive. I do want to get my hands on one eventually or try to make my own but that will be a long term future project.

@@Zenodilodon - Yeah I see possibly InGaN, sapphire, and something else for 450'ish nm. Are you planning on TEC cooling? I'm currently working on a TEC cooled handheld w/ NUBM44-V2. DPSS is next for me too.

@@CG-cw3ps For DPSS and long use for lab/show systems I do TEC cooling. For things like pointers I tend to not bother because there usually isn't enough thermal mass to disperse the heat made by both the laser diode and TEC. DPPS laser heads use TEC to control the temperatures for certain parts like the filters and second/third harmonic crystals to keep them the right size to operate properly. Thermal expansion/contraction needs to be kept to a minimum and these parts are normally set for a very tight tolerance for stability.

@@Zenodilodon - I read the efficiency doesn't justify the effort but I just want to see how long I can sustain peak power before things die. Computer modder and automotive racing tuner.. just like pushing envelopes. I was in development of a threaded Cu core/module that threads into a finned aluminum body and it worked as well as it could.. threading for surface area and aluminum to quickly dissipate the trapped thermals. It just didn't go as far as required to maintain nominal operating temps in new 9mm LDs pushed beyond spec. Thank you for the insight though. Clearly your project is more involved and I have yet to fully immerse myself in the world of optics. Would you be using a blue LD as the pump or the crystals to achieve the blue slice of the spectrum?

@@Zenodilodon - Now that we're friends lol.. Have you ever seen interference for a short distance (6" to 24") and then the beam continues on it's original path.. after the gap? Have you ever interacted with something outside of the human visual spectrum that left behind solid visible matter?

Sadly you can't just pump 808nm into a doubling crystal (ktp, lbo, bbo) and get 404nm

If you make a resonant cavity around the crystal, you might get a bit of 404nm light

You can double 808nm to 404nm, it's just difficult to find the crystals/optics. Some one on LPF used to sell the crystals for this but I have not personally seen them or have done it. Dye lasers are very tricky. You need to pump the dye very quick to the single excited state and try to avoid the triple excited state, this means either the laser dye has to be circulated at great speeds or a pulsed laser light is used. The dye also needs to be in a resonator. If you have enough pulse energy a bare curvette can work but most of the time you need a proper HR and OC. To tune a dye laser you also need a special prism set or diffraction grating for the HR. This stuff gets very complicated. Check out this YT channel for excellent DIY dye laser videos. kzfaq.info/love/0ptp5KuvAJmp8kRV8dqZDA

@@Zenodilodon I already knew that chanel

@@suhailab3634 Why does that not surprise me lol. I think it will help @ARCSTREAMS though if he has not seen it.

Seems like you dig this laser research stuff. I recently found a PDF on the creation of yellow lasers using 2 blue lasers as the pump source. If you are interested in the document I can email it to you.

Zenodilodon that sounds really cool. May I ask you to just send me the web address or the link to where you found the pdf rather than that I write my e-mail here where everyone can see it? If its not too much to ask.

@@yasurikressh8325 I was uncertain if I could relocate the original web page. here it is though. www.researchgate.net/publication/321407519_Diode_pumped_DyYAG_yellow_laser

Zenodilodon thanks :]

Like a mixed gas laser? Because I would love to own one :P

@@Zenodilodon Mmmmmm maybe just maybe....... cogitates .....

I know it's possible to make a TEA laser pointer, I should get to doing that again. I see little reason why a mini mixed couldn't be possible, although battery life would be about 3 minutes lol. Lot's of projects to come as I can afford to make them. Frivolous expenditures for science seem unending...

@@Zenodilodon My own Ebay account is very "hurty" i have to resist before it becomes an "ouchy" (cue wifes hurling of large scientific tomes at head of large idiot)......... :-)

@@qutube100 My GF is slowly getting sucked into lasers. She likes fire so when she learned of burning lasers it was a good mix of interests. She wants to eventually get a channel going herself on KZfaq. I figure if she did she'd probably kick my arse in subscribers lol. I don't know how things would go if we moved in together, we both are science nuts who fill up desk space in little to no time.

Oh yeah, many higher end lasers have desiccant packs or are put in an inert gas chamber like some of the coherent OPS products to try to keep the crystals in good condition. Sometimes they can be restored by baking the water out slowly if you catch it before the coating go bad.