New member, Long time lurker from LA California

[paul1598419]

Im beginning to appreciate other colors of the spectrum and this one you're talking about in particular peaks my interest. There was a "488nm lab style laser" up for sale on ebay that I managed to snag for 30.99 from techood. It's supposed to be 60mw but I don't have an Lpm although the beam is pretty visible. Being the first laser near this wavelength that I owe, I'm not too sure if it's an accurate nm rating but it sure is beautiful and at 30.99 I felt like it was a deal and I'm really liking the color

I have seen those lasers on eBay. I don't know that they are 488nm as the diode they use can easily be as high as 492nm. If it looks cyan, it will likely measure higher than 488nm. They didn't add a fan to the back of this laser. If you did that, and it wouldn't cost much to add it and the power to drive it, you could set the current to 300 mA and get twice the power they are claiming for it now. I have no need for one, so I haven't purchased one, but it is a good price considering it comes with a driver too. It cost me a lot more than that to build mine.

 

[LaserRanger]

I have seen those lasers on eBay. I don't know that they are 488nm as the diode they use can easily be as high as 492nm. If it looks cyan, it will likely measure higher than 488nm. They didn't add a fan to the back of this laser. If you did that, and it wouldn't cost much to add it and the power to drive it, you could set the current to 300 mA and get twice the power they are claiming for it now. I have no need for one, so I haven't purchased one, but it is a good price considering it comes with a driver too. It cost me a lot more than that to build mine.

Yeah the one I got included a fan and driver for both laser and fan with a tty connection on the driver, although the driver needs 12v power to run.
That laser is on my profile picture but it gets washed out by the 445nm light from another laser. The color is like a sky blue with a hint of green. My camera doesn't capture the color as I see it with my naked eye

Edit: I can try to post a picture if you'd like

 

[paul1598419]

That is good news. You already have a fan on it, so you could run the current up to where it output ~120 mW and as long as the driver doesn't run too hot, the diode should be fine. I have built many lasers using Sharp diodes like this one as the others are basically the same diode only a slightly different range of wavelengths. If you don't have an LPM, you can still pot mod it by sight. Just keep an eye on the driver's output device for overheating.

 

[RedCowboy]

Welcome to the forum, I'm glad you read 1st and you mentioned safety which is the most important thing when working with lasers, sounds like you will do well.

 

[LaserRanger]

That is good news. You already have a fan on it, so you could run the current up to where it output ~120 mW and as long as the driver doesn't run too hot, the diode should be fine. I have built many lasers using Sharp diodes like this one as the others are basically the same diode only a slightly different range of wavelengths. If you don't have an LPM, you can still pot mod it by sight. Just keep an eye on the driver's output device for overheating.

I will see about that when I get home, I honestly have not messed with it since it's the first laser in this wavelength and I don't want to risk killing it yet. But I am interested, I've had it running for 5 minutes without any noticeable changes in temperature at the heatsink/diode although there's a very slight temp increase on the driver which I think is normal

 

[paul1598419]

Yes, you can expect the driver output device to run warm to hot. If it runs hot, I will attach a heat sink to the device using Arctic Alumina thermal adhesive. It works very well and will help keep these devices from overheating. Somewhere on your driver board is likely a multi-turn pot. You adjust the diode's current with it, but it may increase in either direction. So, if you can't measure the power you will have to look at the beam to see which way causes it to increase in intensity.

 

[hakzaw1]

@ paul-
I same thing I said..
Once I got one and tested it..& saw the shade of blue.. stable-- fan cooled. ~80mW untouched.. (tempting)
today the fifth one arrived... cannot beat that price.
some will be used for 'R+B = 'Magenta'
and some for G+B= 'teal'
these 488 drivers have a spot for a second laser & TTl for both..
Con: preset focus.. removing the front may not be 'super-easy'
Once I get good regulated (not warts) 12v PS for all I will do side by side to see where the focal point is on each.
good thread!! thanks

 

[paul1598419]

Hi, Len. I didn't know you had purchased that many of these lasers on eBay. You should be able to answer the question of whether they are really 488nm or not. Anything at 488nm or below looks blue by itself, but higher wavelengths are cyan. The higher the wavelength the more green there seems to be in it.

 

[LaserRanger]

Yes, you can expect the driver output device to run warm to hot. If it runs hot, I will attach a heat sink to the device using Arctic Alumina thermal adhesive. It works very well and will help keep these devices from overheating. Somewhere on your driver board is likely a multi-turn pot. You adjust the diode's current with it, but it may increase in either direction. So, if you can't measure the power you will have to look at the beam to see which way causes it to increase in intensity.

@Paul OK will look for that pot and report back with results. Wish me luck so that I don't kill the laser or driver lol

Edit:
Bad new Paul.. My driver does not have a pot. It's all smd resistors, diodes, an inductor, a couple of transistors, capacitors and 2 chips/microcontrollers? But no pot

@hakzaw1
Hey Hak, I've seen the other laser connector, a red diode maybe?
After removing the fan I found a diode mounted on what I believe to be a 20mm aluminum module.
And I happen to have lots of 12v 3.5A switching power supplies that are left over from security cameras I install from work. They end up being thrown away so I've kept a few around. Maybe I can send some your way?

@RedCowboy
Thank you for the warm welcome. I recognize your name as being very helpful throughout the forum along with many great member too and yes, the danger of lasers was made apparent to me after seeing one burn for the first time. I thought to myself, if that light can burn through a plastic CD case or burn wood, light matches, what would it do to my skin or even worse, my retinas!
There's a proper way to enjoy lasers and a proper place to enjoy their beams too. Thank you once again and I'll be in your care

 

[paul1598419]

There are other driver boards you can get that are adjustable and have a circuit to drive the fan too on eBay. Seems like the ones I've seen are around $10.00 or less. You can even use just one part of an RGB driver to get adjustment of your diode's current. You needn't do anything at all with the other two. Just a thought in case you were interested in increasing the power of your laser.