Active cooling of 20x DVD diode  to get more

Hi,

I've been busy collecting things towards my first burning laser.
So far I have a 20x Pioneer DVD writer and 3 16x writers to experiment with.

I was thinking about using active cooling, as I have a mini fridge with a broken door I could use the parts from.
I know condensation would be a huge problem, so I decided to go for a sealed diode housing that will keep moisture well away from any parts that are below room temperture.
The beam would exit through optical quality coated glass, to maintain beam quality as much as possible.

I need to know how much current can I throw at the 20x DVD diode when cooled with a 50 Watt TEC?

How many mw of red could I hope to get, while still having more than a few hours diode lifetime?

Do red diodes shift wavelenth when cooled, if so, by how much, upwards or downwards?
(I know active cooling of DPSS lasers causes problems because of this.)

I should start the build in a few weeks time. I'm having a few weeks off work for an operation, and
need something to keep me from getting bored while I'm stuck at home.
I'll take photos as I go along and pop them on here

Re: Active cooling of 20x DVD diode  to get more

First off, you can get 16x diodes for $20 a pop here.

Second, I don't know that actively cooling the diode will help any, unless you're needing it to stay on for more than a few minutes at a time. I used Kenom's Dorcy Jr. tutorial (I'll link to it later. ), and it was just fine for runtimes of up to 4-5 minutes with a small heatsink. the diode actually seemed to perform better when warm.

And I haven't noticed any wavelength changes while actively cooling diodes.

Lastly, I think you can throw upwards of 300ma's of current at it without shortening the diode life by much... not sure though, as I haven't done an open can in a while.

Re: Active cooling of 20x DVD diode  to get more

Is that 20x an open can? They will take more current. As for TEC cooling, some have reported a little more output but there is a limit as to how much the die can produce. Heat is only one limiting factor. I'm sure one of the members who has worked with a TEC more than me will find this later and comment.

Mike

Re: Active cooling of 20x DVD diode  to get more

I did a project with an open can using TEC. It's definitely one of my favorite builds. I got a lot of help from Gazoo, and other forum members. I learned many things from the project. As Mike said, there are other factors that affect the power. But the LD will only take so much current. One big difference I found, was acrylic lenses vs the Meredith glass lens.
It's kind of a long thread, so here are some of the highlights...

The beginning of the thread is here:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1197272621/0

When it was all said and done, I ended up with a portable TEC (with fan and heatsink), adjustable power, open can laser:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1197272621/45#51

I have currently settled on 450mA's and a Meredith acrylic lens:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1197272621/105#116

I did push it once with some amazing results here:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1197272621/90#100
Jay

Re: Active cooling of 20x DVD diode  to get more

Thanks for the advice and the links.
Loads of useful advice and info for my project.

Does anyone know where to get 500mw+ red diodes from in the UK?

I'd love to join the class 4 laser club as soon as can.

I've been messing about with 5mw and 10mw lasers for too long now. (almost 10 years)
Now high power lasers that can burn things and do decent outdoor effects are
becoming more affordable. (I prefer to do laser art, rather than burn things. it's fun to show off to
friends, but I love a good laser show. I'd love something in the half watt range.
Or should I just save up and get a 500mw green module+psu off Ebay?
I got my 350mw RGY scanner from LaserWorld in Gemany last year and I noticed they
now sell the laser modules and PSU's they use in their scanners as OEM items.