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OK This is weird.....

Things

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I have been playing around with my RGY lately, and have taken the front off. But what confuses me, is the RED laser is leaking IR! Its a 100mw red, and it can't be a diode if its leaking IR, why would you put a DPSS red in a cheap scanner if a diode is cheaper? I am fairly sure it is DPSS, why else would it have IR in it? Another strange thing i noticed, is that on the other side of the dichro, there is a ORANGE output :eek: :eek: :eek:. As far as i know, you can't colour a laser with a dichro, and the green laser was FULLY unplugged, so it wasn't mixing, do DPSS lasers leak other wavelenghts? I know BlueFusion also noticed orange output from his DX 30. The orange is really dull, most likely 0.1mw or less, but there is deffiantely orange there, it has been comfirmed by about 6 people. The only reason BlueFusion and i can think of its that the crystals are leaking other wavelenghts, which are converted into orange. Do DPSS lasers do that?? Here is a few pics, one showing the IR output from the red laser, and the other is a very blurry one of the orange dot. BTW the orange is still collimated, so its deffinately laser output. Any idea's?????
 

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Things

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Blurrry orange, remember this is only way less than 1mw output, hard to take pics of.
 

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BlueFusion

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Yeah, my DPSS green DX 30mW leaks some orange 593.5nm and blue 473nm.
I hypothesise that the Nd:YVO4 is emitting some 1347nm and 946nm doubling to 593.5 and 473nm respectively, but this is insignificant in comparison to the green output.

It certainly does appear that the red used here is DPSS red.
Yes, DPSS lasers leak a whole lot of wavelengths. :D
hell, in mostly small amounts, my DX 30 produces: 1347, 1064, 946, 808, 593.5, 532 and 473nm!
 

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Hmm if i had some googles(which i really need) i will try to see wht this thing really is, but yeah, i agree with Blue's hypothesis.
 

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I thought blue lasers use LBO crystals? Can you make blue with KTP? Besides yellow DPSS is not frequency doubled, it's sum frequency :p
 

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A eye toy for ps2 modded for PC use, with its IR filter removed. Pointing the camera at a IR led gets the same results, so its deffinately IR in there somewhere.
 

BlueFusion

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actually switch... yellow DPSS is doubled. Its 1347nm emitted by the Nd:YVO4, its third strongest line, which is doubled to 593.5nm.

Most DPSS lasers (green, orange, blue) use Nd:YVO4 and KTP. They simply have totally different coatings, to promote the desired wavelengths and suppress others, otherwise it'd simply emit a mash of all different stuff and not really lase at all.
 

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There are different coatings for the blue and yellow lasers, or different crystals, If it was possible to make a blue or yellow laser from a greenie, they would be just as cheap...
 

Tallaxo

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Things.

The red module inside the scanner is definitely NOT dpss. It is a diode laser. May I ask, how do you know it is emitting IR for sure? If it is IR you are detecting, it has to be from flourencence of the focusing lens itself. A photon created by flourencence will always be of lower energy and a longer wavelength than the photon that stimulated it, therefore a 650 red, if it was flourescing (sp*?) it would do so deeper into the red spectrum (IR)

As to the yellow / orange colour, that is an easy one to explain. I became intrigued when I thought my blu rays were emitting yellow and orange before they started to lase properly at normal operating currents. Using my precision bench power supply and a small magnifier, I began to crank up the current by 1ma increments to see if I could see what was causing this. Looking directly into the diode window, The yellow / Orange colours were actually produced from internal reflections of the diode can itself and the gold coloured contact wires. on low powers before actual lasing commenced , this was very easy to see as non coherent and non monochromatic light leakage from the fast axis of the faceted mirror (basically an LED effect).

Hope this helps.

Jase
 

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BlueFusion said:
actually switch... yellow DPSS is doubled. Its 1347nm emitted by the Nd:YVO4, its third strongest line, which is doubled to 593.5nm.

Most DPSS lasers (green, orange, blue) use Nd:YVO4 and KTP. They simply have totally different coatings, to promote the desired wavelengths and suppress others, otherwise it'd simply emit a mash of all different stuff and not really lase at all.
I just read in a review from the led museum that yellow DPSS is sum frequency, I'm confused :-X
 




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