simple "normal" red laser curiosity

[ShortyInCanada]

"The pump frequency would have to be in the IR region to generate green. "

I guess that starts to explain the standard DPSS greens that are out there now. Same sort of theory but with different materials.

Will there be a test on this soon ?
I need to clear my thoughts for studying.
(Haven't had to do that for 20+ years.)

 

[Benm]

I think the most likely cause are impurities in the semiconductor material, at high current the tiny probability of them being excited is noticeable enough.

I agree with this concept.

I suppose its entirely possible for the laser diode to emit a bit of yellow/green/blue stray light while lasing along at 660 nm. The pictures as posted do not indicate this green light to be coherent or otherwise laser based at all, you're looking directly into the laser diode so you will see whatever is emitter there after the red has been filtered out by the solution.

Proof for any SGH or other multi photon effect would be a green beam originating within the solution, like what happens in dye lasers. Exclusion would be possible by putting some anti-green goggles between the laser and the solution - any green still visible after that must have come from the acetate solution and not the diode.

 

[Bionic-Badger]

Hmm, I think this article mentions lasing at wavelengths around that green range in copper acetate. Probably a bit different though.

 

[Benm]

I can only see the abstract, but somehow that already makes me thinkt his work was done in the gas phase.

 

[Bluefan]

Hmm, I think this article mentions lasing at wavelengths around that green range in copper acetate. Probably a bit different though.

Laser action in copper at 5106 and 5782 Å is reported from double pulsed discharges with a new lasant, cupric acetate, at an optimum temperature of 230 °C. Several interesting laser characteristics observed as a function of temperature and delay between pulses are discussed for both transitions.

That's a copper vapor laser, not very likely (read: impossible) to happen inside you diode