501-561nm?

[Fenzir]

I was looking around and had stumbled upon this.
Focalprice.com offers 100mW 501-561nm Strongest Green Laser Pointer ,discount 100mW 501-561nm Strongest Green Laser Pointer,100mW 501-561nm Strongest Green Laser Pointer products,low price 100mW 501-561nm Strongest Green Laser Pointer,cheap 100mW 501

Now, not only the "strongest" lable turns me off, but how does it mean 501-561nm?
Now I'm no diode-ologist, but aren't diodes usually pretty controlled? I see the power stickers on lasers claim +/- 5nm, but +/- 30nm?

Going by this, which isn't the most accurate...

That could get a nice bluish color or a pretty generic green.
Can any body clarify what I'm looking at here?
I used search and couldn't find anything and the product seemed.... all out of whack.
I know it's from an unrepeatable dealer... just wondering.

 

[Toaster]

It's a 532nm Laser. Yes there is no such thing that is tuneable to that extent. (That I know of)

 

[Fenzir]

I recall hearing tha you could alter the wavelength of a 635 by altering the mAH, pushing it with more power would increase the wavelength?

 

[Toaster]

Thats where the +- 5nm comes in

 

[Trevor]

I recall hearing tha you could alter the wavelength of a 635 by altering the mAH, pushing it with more power would increase the wavelength?

You alter the wavelength a laser diode emits by heating or cooling it. Higher currents without active cooling generally means more heat.

You lower the wavelength of a laser diode by applying a massive amount of cooling.

In the case of green DPSS, the temperature of the crystal does not affect the wavelength it lases on. The same transition of the neodymium will be lasing no matter what the temperature. Technically, 532nm is between 501nm and 561nm. :na:

But, FP obviously wants to fool buyers into that purchase.

Also, mAh has nothing to do with the wavelength of a laser diode. It is how battery capacity is measured.

 

[Gryphon]

I have a bunch of 400-700nm lasers

 

[Cyparagon]

I've got a CNI laser head that says the same thing. It is 532nm and does not change.

 

[rhd]

You know what they say....

"One man's 5mW 532nm, is another man's <300mW 510-560nm"

 

[firelight]

Wavelength should have little to do with power input. Lasers fundamentally work through stimulated photon emission caused by exciting gases or semiconductors (in diodes) The wavelength of the emitted light corresponds to the band gap energies of the semiconductors in question (when dealing with diodes) and the energy gap between an excited and rest state of electrons orbiting gas atoms or molecules (for gas lasers). Just seems like advertising and/or lies to me...

 

[Trevor]

Wavelength should have little to do with power input.

If some of that power input sticks around in the laser diode in the form of heat, the wavelength at which it lases will increase.

This does not happen in gas / DPSS.

-Trevor

 

[firelight]

Very true, but it still shouldn't be a drastic change.

 

[Trevor]

Chilling can drastically change a laser diodes color. So can letting it heat out of control.

I know at least one flavor of diode changes ~0.3nm per degree Celsius.

-Trevor

 

[firelight]

then to change the output of the laser from 501nm to 561nm, you would have to change the temperature (61nm)/(0.3nm/C) = 200C. That's a little outside my comfort zone for holding the laser.

 

[chipdouglas]

You alter the wavelength a laser diode emits by heating or cooling it. Higher currents without active cooling generally means more heat.

You lower the wavelength of a laser diode by applying a massive amount of cooling.

In the case of green DPSS, the temperature of the crystal does not affect the wavelength it lases on. The same transition of the neodymium will be lasing no matter what the temperature. Technically, 532nm is between 501nm and 561nm. :na:

But, FP obviously wants to fool buyers into that purchase.

Also, mAh has nothing to do with the wavelength of a laser diode. It is how battery capacity is measured.

cyparagon has been testing some reds 650s. he was testing them in a freezing tec cooled heatsink. his tests are showing that wavelength shift is not just exclusive to temp.

michael.

 

[Trevor]

then to change the output of the laser from 501nm to 561nm, you would have to change the temperature (61nm)/(0.3nm/C) = 200C. That's a little outside my comfort zone for holding the laser.

I am not trying to tell you that this handheld is based on a laser diode tuned by heat.

I'm trying to tell you that heat can quite drastically affect a laser diode's wavelength. Science!

cyparagon has been testing some reds 650s. he was testing them in a freezing tec cooled heatsink. his tests are showing that wavelength shift is not just exclusive to temp.

michael.

The composition of the laser diode does it too (InGaAs vs. InGaN).

What's he found out? Link?

-Trevor

 

[chipdouglas]

i'll pm him.