Cheap RGB Lasers, avoid or buy?

[Laser57]

I am seeing some high power relatively low priced Chinese RGB White lasers on both ebay and Aliexpress listed, up to 40 watts. Are they stable enough without failing quickly? Perhaps the diodes driven too hard? None of the listings will give information on how many diodes are in it for each wavelength nor the manufacture part numbers for them to be able to know.

To compete, I have come to expect the Chinese cut corners everywhere they can, perhaps push the diodes too hard or list the product output powers higher than they really are.

Examples of relatively low priced RGB white lasers for the stated output:

https://www.ebay.com/itm/364499815712

https://www.ebay.com/itm/364588546310

[Laser57]

I received an answer from a seller of the 15W RGB unit regarding the number of diodes used;

Output power: R:4W, G:5W, B:7W

8 pcs red laser diodes, 4 pcs green laser diodes and 2 pcs blue.

So, perhaps the 15W white laser isn't overdriven too much, but they refused sending a photo to me showing the inside, as most won't, fearful I might post it. That just makes me want to do so.

https://www.ebay.com/itm/364588521828

Video of the insides of a 5W RGB I bought from another manufacturer some time back:

https://www.youtube.com/watch?v=Soj4YXzyreU

[Draco]

I would recommend Kvant or Golden Star Lasers for RGB Blocks. One problem that these other RGB lasers is the drivers well suck, they lack the bandwidth needed to display graphics or any other high-speed projection and some of them have the diodes pressed or glued in so repairing them is harder. One of my Gloden Star Blocks is running on all new diodes so for me serviceability is another thing to look for. Blocks that use a plate with 4 screws to keep the diode in are easy to work with, no need to pry out a dead diode and opens the door for other color diodes or power levels and the removed diodes can be reused in other stuff.

The switching drivers common with the Chinese laser blocks I think have a bandwidth of about 10-20khz and in my application meant that the colors where off and where a line should stop left a trail so with the golden star laser block of 1 watt that I have 2 of I had to switch out the stock switching driver with 3 Simpledrives (that are no longer available). We have a projector with a 5-watt Golden Star Laser block that is a sharp beam series and comes with analog drivers that work great. The Simple drive v2.5 have a bandwidth of 100khz and that seems to be fine for laser projection. The Kvant block that I have has drivers that can do the job as well.

The Kvant block I had an alignment problem and sent out an e-mail to them and they responded FAST and sent me the instructions to fix that block , it has one 450 blue running at 1.5 watt and 6 knife edged red diodes with a power of 1 watt and all the corrective optics and TEC inside.
My self I would skip some of the stuff from flea bay unless it's from a company that will respond if you have a problem with it, or just go direct to the manufacture, I am in love with the Kvant block I have.
Thats my current train of thought for RGB blocks
Draco

[Laser57]

Great stuff, thank you for sharing. I had gone to the Kvant web site the other day, will look at Golden Star next.

[edison]

Brightlight is also an option. 19x19x21cm size. 7K weight, Up to 20W RGB. Completely hand build in the netherlands.

[Laser57]

Do you have a web site? I deleted my FB account years ago, refuse to use them.

[Draco]

I would love a web site as well, I am starting a 3rd build and have not done anything with my second build, still need to post stuff on my last one. I wish the software to run these things was cheaper, it's a hobby with my own stuff, the one company I work for can afford all the cool stuff, but 600+ for a pangolin program that works with sound, the 540 version does not, so another 600 so it responds to sound is highly annoying, LaserOS with the LaserDOC (not going to by a projector that lacks an ILDA input, and can only run at full power for something like 5-10 seconds) does it if your lucky to have the DAC but they can be buggy and not always work. One show we did we had to use my LaserDOC as the other one would not connect.
God I wish they had a hobby version to do 3d stuff or to just have it react to sound.

Draco

[Laser57]

I don't know what happened, he responded to me here on PM with his email address, but when writing him telling him I don't need a projector, instead just a diode combined laser and then crickets. Maybe he didn't get my email, will try again.

[edison]

Have read your PM. My suggestion would be since its just a small hobby project you have going on check ebay or contact goldenstar if you need a module. We only sell complete projectors. I have sold modules and kits in the past but with kits i discovered that some people couldn,t even do proper soldering and with modules i had to be a teacher how to build a projector. Its much easier to sell a complete working system. In the selfbuilding days people build because it was cheaper then buying and it gave them also sort of awarding feeling. These days are long gone... the only driving force is cheaper. cheaper to build and DIY market is booming, cheaper to buy DIY is gone. The DIY market was mainly driven by enthousiast people with interest in technology and at the same time save a few bucks allong the line. PhotonLexicon was an exciting place with many people showing of their projects but that was then.... Its a shame not much is going on....

[Laser57]

Understood, cheaper to buy, especially projectors. I am interested in an RGB, but not for laser shows or projecting. I'd love to have a high power RGB pointer (dare I say the word in this group of professionals) which has decent divergence of under 1.5 mRad at five watts total power or greater. I have a relatively low power single mode RGB pointer I bought second hand I love, but due to age the power output is now under 500 mw. There are no RGB pointers I can find offered by anyone at higher power than that, so it's either I find someone to build it for me or build it myself. However, I have nil machining ability which has stopped me from being very creative but have worked as a RF technician or engineer for decades, so know how to use a soldering iron.

Due to all of the above I've come to the conclusion to settle with a single wavelength higher power pointer, perhaps built out of a modified laser brick used in a projector which has a rectangular shape and an output on the long end, but not finding one yet. About two years ago I built a dual NUGM04/FAC 525 nm laser diode pointer using a rotator and PBS cube which works well, but the output is under 3 watts. There is a "4 watt" dual NUGM06 diode 525 nm pointer being sold now, but they are not telling the truth, it's really about 3 watts output power, otherwise I'd probably buy one of those.

I recently purchased some very nice knife edge optomechanical assemblies from lasertack, might build those into a large pointer body I had machined a few years ago. Just need to figure out how to reduce the divergence of the outputs which is a trick when in that configuration, probably isn't possible, but I am trying to think outside of the box for a solution.