20 Diode Modules

[gottaluvlasers]

wait a minute...hold the phone....pause.....

its possible to wavelength shift *that much?* you can take a 445nm diode and cool it enough to emit a red wavelength? that is amazing. I knew diodes shift wavelngths a few nm here and there with temp. But i had no idea it could be this extreme.

In theory, could a 445 diode be temp shifted from high temps to very cool temps and cover the whole visible spectrum? is that possible?

This is really interesting.

Planters-

Truly spectacular work! excellent workmanship and beautiful design. cant wait to see this thing lasing! ~640nm red coming from 445nm. Fookin cool man!

-Marc

[allthatwhichis]

No, I think you missed a bit. He is making two laser arrays. One red, using 660nm reds that when cooled to -30c will produce 646nm light. He did not indicate what he expects the blue laser array to produce at -10c.

I'd like to see more of those water-cooled TECs.

[sugeek]

Nice,

Keep up the good work, that looks great! Motorised mirror adjustment is the only thing I could suggest to make that better! As many pictures and videos as you are willing to post is a request!

-Adam

[planters]

Wait! Hoooold on. Temperature shifting/tuning is only really effective with red lasers. The 445nm GaN diodes show so little temperature shift that temperature tuning is impractical. Nevertheless, some Russian researchers showed in experiments with these red diodes that the blue shift continues down to LN2 temps and wavelengths down to 610 nm were produced. Cooling the blues is to increase their efficiency and to allow them to survive power output approaching 2 W.

Dnar, the parallel reds/resistor combos are being run at 14.5V and 1,400ma and the power output is linear to a slow sweep of the modulation voltage up to 5V.

[allthatwhichis]

Thanks for the verification; any chance these beasties will make it to SELEM?

[masterpj]

Oh please god take it with you to SELEM

[dnar]

Oh please god take it with you to SELEM

I bet you say that to all the mad scientists and engineers.

[hivelaser]

So the 445nm LD just shift a little, is it possible to hit with them 455nm or even 460nm, if yes at what temperature do they need to be run, if possible. Also to let the Reds (660nm) run at 646, what temperatures are we talking about.

[masterpj]

I bet you say that to all the mad scientists and engineers.

LOL? how did you come to that conclusion

[planters]

I've tested only3-4 of these diodes and their native ie. 30C wavelength varied between 455 and 460 nm. To achieve a 5nm wavelength shift with only temperature would probably require a 200C-300C delta and this just isn't practical.