Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

FrozenGate by Avery

Green laser spot being orange on orange surface

AFAIK green laser diodes are just infrared emitters with the crystal shortening the wavelength by half. Am I wrong?

And why my 405nm laser seems to fluorescing much more than green one, on more kinds of surfaces and much brighter?

Sorry for somewhat newbie questions, I am new to lasers, but started studying photonics, so I am trying to get most information I can about laser stuff.

And I am wondering why this 405nm lasers on pickles has violet spot. On all layers on which the color is changed the resulting color is the one thing has. But pickles are green and it's very non-violet color.
 
Last edited:





Each 405nm photon has more energy than each 532nm photon... I think the higher energy makes it fluoresce stronger

And yes DPSS green lasers use IR diodes, but we now have 520nm direct green laser diodes
 
And some DPSS green lasers have decent Infrared cutout filter to kill off 808nm / 1,064nm Infrared laser light, leaving 532nm green light untouched.

I have 520nm laser diode also. Pretty nice compared to DPSS.
 
No dpss lasers use infrared input to a catalyst molecule that in turn emits a collimated and synchronized photon of the green spectrum wavelength
 
Last edited:
xirrious said:
No dpss lasers use infrared input to a catalyst molecule that in turn emits a collimated and synchronized photon of the green spectrum wavelength
Click to expand...

The 520nm green diode are DIRECT green laser diodes that emit light at 520nm directly form the laser diode cavity

The green DPSS @ 532nm , uses a 808nm pump diode to cause a ND doped crystal to fluoresce and lase at the IR line 1064nm , Now the 1064nm photon has half the energy of 532nm photon , so when the 1064nm photons enter the KTP crystal , in simple terms two 1064nm photons combine to produce a photon with twice the energy , thus you get a 532nm photon .

The direct diode @ 520nm , uses electrons that travel from a N to P layer ( electrons and holes ) and when they do , they loss energy in the form of photons , these photons bounce back and forth inside the cavity inside the die and stimulate other atoms in the cavity to also emit photons of the same energy , in this case its 520nm , these then exit the die though the OC mirror .

Green diode and green DPSS are two very different things .

The post above you , he said green diode , so what he said is correct .
 
Last edited:
DPSS laser crystal (such as KTP or BBO for example) imprisons Infrared laser light, and at this point the only way the laser can escape the optical prison is to, due to nonlinear optics physics, convert to double that or the byproduct of the summed (heterodyne) laser wavelengths in order to bypass the cutout mirrors that keeps fundamental wavelength trapped but allows the converted wavelength to leave.
 
My green laser pointer is 532nm. Doesn't that mean that it's converted from infrared?

And why pickles fluorescence in violet while being green?
 
For 532nm lasers, pretty much. It's a product of 1,064nm infrared laser. However for 530 - 510nm laser, it's from the Gallium-Nitride laser diode which has zero infrared emission.

About pickles, interesting. Fluorescence from pickle may be from seasoning or something tossed in for to make it either sweet or sour. Even plant extracts will fluorescence too (I have readed up about "tea leave laser" - not so sure if it's a hoax or not but everything's possible).
 
Many common objects will fluoresce, but you're better off using a 445 or 405nm laser to explore them. For example, peanut butter will leave a glowing trail very briefly if you shine a 445/405nm laser at it.

Like others have said, things can only fluoresce at a lower energy than originally put into it, so you could get IR/Red/Orange/Yellow fluorescence with a green laser, but you could only get IR and deep red with red. Whereas if you use blue/445/405nm, you can get lighter shades of blue, and everything from IR/Red/Orange/Yellow/Green etc.
 
Last edited:
Cool. Whenever I get my hands on the high speed Blu-ray Disc (10x or faster - 450mW+) 405nm laser diode, I would definitely try that. I didn't know that peanut butter would have some sort of phosphorescent persistence (I do know it glow weird green under 365nm light - I have 10 Watts 365nm LED somewhere).

EDIT: Found the YouTube video clip demonstrating the peanuts' phosphorescent presistence after being shone upon by a 405nm laser. Not my video, BTW. https://www.youtube.com/watch?v=pFossPlezq8&feature=youtube_gdata_player
 
Last edited:
Things said:
Like others have said, things can only fluoresce at a lower energy than originally put into it
Click to expand...

That is mostly true. There are some special upconverting phosphors, but I have never seen it
happen in everyday objects.

I just tried the pickle thing. It didn't work at first. Turns out the skin and only the skin will do
it. If anyone can get their hands on cucumbers this time of year, those are what they make
pickles from.
 
The Lightning Stalker said:
I just tried the pickle thing. It didn't work at first. Turns out the skin and only the skin will do it. If anyone can get their hands on cucumbers this time of year, those are what they make
pickles from.
Click to expand...

I am not sure I understood you.
I was checking this on a slice of a pickle, shining light onto it's surface and it turned violet. I didn't check the outside layer of a cucumber (if I understood you meant that saying skin).
 
Maybe it's just the batch of relish I was trying it on, but it has to be the outer skin. The inner flesh will not
do it. There are no pickles in the house, just this jar of sweet relish.
 
I know that may sound stupid, but have you tried 520nm laser? It, of course, has more photonic energy than is the case with 532nm laser - every nanometers count. I haven't tried that just yet even though I own both 532nm and 520nm lasers. Just a suggestion, for givin' the inner pickle flesh fluorescence a try.

I may try pickle from Mini Mart in a couple of hours, still early in the morning (and it have been snowing significantly here).
 
Last edited:
You must log in or register to reply here.


Back
Top