Lens?

[Wolfman29]

Hey guys,

My 445 diode is coming in the mail today, and I am looking forward to putting it in my box (have had this build ready for weeks now). But, I just realized that I probably need a great lens for a long-lasting diode and more power....

Which lens should I use? The 405 Aixiz lens? Normal glass lens from Aixiz? Any other suggestions?

I plan on running it at around 1.25A, but I just don't want to damage the diode. I realize I won't have a nice lens on it for a couple of days, but I won't put that much use in it until I get my lens anyway, and I am sure the diode can handle a couple of minutes of run time with a normal, Aixiz acrylic.

 

[bluuray]

it will melt it easily ( the acrylic) and it will get on the diode and screw it up
wait for your glass

 

[Wolfman29]

Really? Even if I just use it at low currents for testing purposes? Shame...

 

[Coherent Light]

Anything much over 300mW is too much for the Acrylic Lens.

 

[Wolfman29]

Wow. That's very little. Which lens would be the most effective then?

 

[bluuray]

for higher power : 405-G-1
nicer beam but a little less power: normal glass lens

 

[anselm]

You can probably run it at 200-350 mA safely with the acrylic lens.
In the long run, you will want the 3 element Aixiz glass lens, 405nm AR coated.

Here's an idea how much power you can expect at what currents.
http://laserpointerforums.com/f65/3x-445nm-ld-piv-plot-53927.html

 

[blasterman]

Maybe I'm missing something but when I power my 445 at 350mA -vs- 700mA the visible difference is huge.

According to the chart it would be neglibible in terms of mW out the front.

 

[anselm]

What?
200mW @ 350mA VS
700mW @ 700mA.....
negligible??:thinking:

 

[LuxorLasers147]

The axiz lens WONT burn out if the back is openned. btw i killed a 445 for using the lm317t driver with a 0.2 ohm resistor insted os 1 ohm. My meter was damaged and the reading was terrible. (the outuput was huge of course!! probably more than 2W) it lasted 5 min or so -.- and gess what, i was using the standart lens with the back openned and for 5 min, they didnt melt! xD.

 

[Wolfman29]

If the back is open - what do you mean?

 

[blasterman]

Sorry....reading the Vf deviant.....at work and trying to read too fast.

 

[hakzaw1]

The axiz lens WONT burn out if the back is openned. btw i killed a 445 for using the lm317t driver with a 0.2 ohm resistor insted os 1 ohm. My meter was damaged and the reading was terrible. (the outuput was huge of course!! probably more than 2W) it lasted 5 min or so -.- and gess what, i was using the standart lens with the back openned and for 5 min, they didnt melt! xD.

I hope no one reading the above will consider it good advice.

I dont think it was my imagination when i saw smoke coming from an acrylic lens -445nm diode set around 1 A and this smoke appeared in about 40 seconds. advice given like this is bad advice.

Use a glass lens for 445nm diodes-and THAT is good advice.

 

[Wolfman29]

That's so odd then. I have never seen smoke from my Hotlight build and it's running at 1.25A. I have had it on for 30 seconds to two minute or so at a time and I have yet to see any damage to the lens (I have removed the lens multiple times and examined it under a magnifying glass... that's a bizarre image).

 

[Coherent Light]

have you verified the output of your laser with a power meter?

 

[Wolfman29]

I have not. But, I do know that both the dot and beam are significantly brighter than my 200mW Rayfoss laser, and via the eye receptiveness graph or whatever it's called, isn't 445nm supposed to be roughly 20% of 532?