New to lasers

[jordanka16]

I've been reading for a while but decided to finally join. I'm a longtime electronics enthusiast and I decided lasers looked pretty fun. I remember looking into it maybe 15 years ago and powerful lasers were really expensive. I'm kind of blown away with how inexpensive everything is now.

I picked up a lower power red and what I would consider high power but probably isn't Sharp GH04W10A2GC and have been playing around with my benchtop power supply with them so far. Next step is to build them into enclosures and make them more permanent. The only thing I can't really make myself is the enclosure so that's currently my brick wall.

I also plan to do a really powerful 7W plus 450nm build but want to get some practice in first of course. Looking forward to learning lots more!

 

[Shmackitup]

Welcome!

 

[jordanka16]

Welcome!

Thanks! I just bought a bunch of stuff from you on ebay, including a pretty powerful diode for when I eventually get brave enough to use it.

 

[Shmackitup]

Thanks! I just bought a bunch of stuff from you on ebay, including a pretty powerful diode for when I eventually get brave enough to use it.

I appreciate the business! Please make sure you get yourself some proper eye protection as well. Feel free to reach out with any questions that may arise. Email is the best way to get a hold of me.

 

[paul1598419]

Welcome to the LPF. I think you'll find the divergence of these more powerful laser diodes is not at all what you expected. The farther out the beam goes the more like a bar or line the beam becomes. One of the best ways to tame that is the use of cylindrical lens pairs, but that takes experience and the need for good eye protection while setting them up. Enjoy your stay and stay safe.

 

[jordanka16]

I appreciate the business! Please make sure you get yourself some proper eye protection as well. Feel free to reach out with any questions that may arise. Email is the best way to get a hold of me.

For sure, I did get a good set of glasses that protect between 190-540nm, I do a lot with UV so they'll help there as well. I appreciate the offer, I will keep that in mind.

Welcome to the LPF. I think you'll find the divergence of these more powerful laser diodes is not at all what you expected. The farther out the beam goes the more like a bar or line the beam becomes. One of the best ways to tame that is the use of cylindrical lens pairs, but that takes experience and the need for good eye protection while setting them up. Enjoy your stay and stay safe.

Interesting, I bought a diode with a housing and a few different types of lens that screw into the front, does it take more than that to get a good beam? I suppose I'll find out when I mess around with them. I did get some proper eyewear for them so I'm covered there.

 

[paul1598419]

It depends on the divergence of your beam which lens to use. For more divergent beams the G8 is preferable. For tighter beams I use a G2. The G8 has a focal length of 8 mm while the G2 is less than 3 mm.

 

[jordanka16]

It depends on the divergence of your beam which lens to use. For more divergent beams the G8 is preferable. For tighter beams I use a G2. The G8 has a focal length of 8 mm while the G2 is less than 3 mm.

OK cool, I bought a G8 lens with the diode housing, and a 3 element lens to build a pointer with, I could certainly order a G2 to try it out as well. Thanks!

The sharp 405nm laser I bought came mounted in some kind of holder with a heatsink and a lens. I've just been messing with that so far. Powering it with a benchtop supply to get an idea of what power level does what. Even at 700mA which should be just about 1W it's really impressive, it burns plastic easily and also my hand, lol.

The lens is also capable of really spreading the beam out for a really powerful focused UV light. It could be really useful that way too.

 

[paul1598419]

Yeah, those single mode 405 nm laser diodes can really be over-driven, but they are not very forgiving. I have lost several by over driving them too much. I found for longer life not driving them to a full watt is usually best.

 

[jordanka16]

Yeah, those single mode 405 nm laser diodes can really be over-driven, but they are not very forgiving. I have lost several by over driving them too much. I found for longer life not driving them to a full watt is usually best.

That is good to know. I don't have much need to make this one extremely powerful anyway, so running it at lower current is no big deal. I'm impressed by how much the lens can spread the beam out, it seems to make a pretty good UV flashlight although 405nm is pretty long. Too bad there aren't any laser diodes around 365nm or even better 255nm. But there are barely LEDs at that point.

One unusual thing, when the beam is spread out there are weird circles in it, is that a product of the laser diode or the lens? Or perhaps just a dirty lens, I haven't taken it all the way apart to see.

 

[Shmackitup]

That is good to know. I don't have much need to make this one extremely powerful anyway, so running it at lower current is no big deal. I'm impressed by how much the lens can spread the beam out, it seems to make a pretty good UV flashlight although 405nm is pretty long. Too bad there aren't any laser diodes around 365nm or even better 255nm. But there are barely LEDs at that point.

One unusual thing, when the beam is spread out there are weird circles in it, is that a product of the laser diode or the lens? Or perhaps just a dirty lens, I haven't taken it all the way apart to see.

There are 255nm and up laser diodes available now but they are very expensive and quite low power.

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[paul1598419]

That is good to know. I don't have much need to make this one extremely powerful anyway, so running it at lower current is no big deal. I'm impressed by how much the lens can spread the beam out, it seems to make a pretty good UV flashlight although 405nm is pretty long. Too bad there aren't any laser diodes around 365nm or even better 255nm. But there are barely LEDs at that point.

One unusual thing, when the beam is spread out there are weird circles in it, is that a product of the laser diode or the lens? Or perhaps just a dirty lens, I haven't taken it all the way apart to see.

Don't know why you are getting those circles. I haven't ever had that problem with mine. If you figure that out let me know why it happened to you.

 

[Shmackitup]

Don't know why you are getting those circles. I haven't ever had that problem with mine. If you figure that out let me know why it happened to you.

The circles are dust or something else on the diode window or lens.

 

[RedCowboy]

Yes, everyone has seen those circles, they are most noticeable on a wall when your lens is fairly unfocused, it's junk on your lens or diode window, you can find out which by turning your lens, if the circles move with your rotation it's a dirty lens, if not then the diode window.

 

[jordanka16]

When I run the diode with no lens it's a very clean beam, so it's something with the lens. I cleaned both sides but the dots persist. It must be something stuck between the elements.

There are 255nm and up laser diodes available now but they are very expensive and quite low power.

Those are expensive, and for not much output. Probably not worth it over an LED at this point.

 

[paul1598419]

No. You'd likely be much better off just using an LED. I rarely if ever defocus my lasers, so I wouldn't have seen the circles. Good luck to you.