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



405nm Photoluminescence

steve001

Well-known member
Joined
Jun 3, 2007
Messages
2,515
Points
113
A while back one dark night in my house I used a 405nm pointer and as I swept it across a white wall, that portion illuminated glowed a pale white for about a second of time; even old white paint from my grandparents hoosier cabinet is photoluminescent. It's not something I expected. I also discovered plaster in my house photoluminescences too. Not something I expected. Curiously, I have some titanium dioxide (tio2) it does not photoluminesce as I recall.
 



CynicalBrad

Well-known member
Joined
Sep 4, 2016
Messages
554
Points
63
Another thing you will find very odd that does this would be peanut butter....
So far I have found that the cheaper LESS processed brands tend to glow longer with Great Value brand having a glow that persists up to a few seconds under my ~800mW sanwu challenger.
 

steve001

Well-known member
Joined
Jun 3, 2007
Messages
2,515
Points
113
Another thing you will find very odd that does this would be peanut butter....
So far I have found that the cheaper LESS processed brands tend to glow longer with Great Value brand having a glow that persists up to a few seconds under my ~800mW sanwu challenger.

Huh. Interesting. I've a class 4 too, but it does not cause the glow to persist longer.
 
Last edited:

CynicalBrad

Well-known member
Joined
Sep 4, 2016
Messages
554
Points
63
My challenger just so happens to be the only 405nm laser I own.
I discovered this with my first laser I built which was a PHR-803T putting out 80-100mW back when the PHR was the king of 405nm output
 

Euphonious Nonsense

New member
Joined
Oct 25, 2016
Messages
178
Points
0
For some reason my 445nm sanwu silver series does this much better than all my other lasers, including the couple 405nms I have left. We have ceramic tiles downstairs that will leave about a 1ft trail behind the dot as you move the laser over it. Was definitely not expecting this the first time i noticed it!
 

steve001

Well-known member
Joined
Jun 3, 2007
Messages
2,515
Points
113
Add cashew and almond butters to the list of things that glow.
 

Benm

Well-known member
Joined
Aug 16, 2007
Messages
8,113
Points
113
even old white paint from my grandparents hoosier cabinet is photoluminescent.

Well, some things just do. I have a wooden table with varnish on it that glows slightly green-ish after swiping it with a 405 laser beam. I have no idea what causes it exactly, it's a very old wood-fineerd table of unknown origin.

Many coloured plastics will do it as well, even though they are not supposed to be 'glow in the dark'. Usually it disappears quicky (in a second or so) but i've seen all kinds of things giving up a bit of remaining light after being hit with a 405 laser. If you have things like plastic soap/shampoo/etc bottles that are yellow, orange or red under normal light, try those :)
 

steve001

Well-known member
Joined
Jun 3, 2007
Messages
2,515
Points
113
Well, some things just do. I have a wooden table with varnish on it that glows slightly green-ish after swiping it with a 405 laser beam. I have no idea what causes it exactly, it's a very old wood-fineerd table of unknown origin.

Many coloured plastics will do it as well, even though they are not supposed to be 'glow in the dark'. Usually it disappears quicky (in a second or so) but i've seen all kinds of things giving up a bit of remaining light after being hit with a 405 laser. If you have things like plastic soap/shampoo/etc bottles that are yellow, orange or red under normal light, try those :)
I've not notice any other materials photoluminesce other than what I mentioned previously. I'll have to see what else does.

P.S. I have a flourite crystal that glows a bit.
 

Seoul_lasers

Well-known member
Joined
Jul 4, 2008
Messages
2,680
Points
113
I've not notice any other materials photoluminesce other than what I mentioned previously. I'll have to see what else does.

P.S. I have a flourite crystal that glows a bit.

Soda-lime glass. It has an orange after glow after hitting it with 405nm.
Calcite that has trace impurities of Mn (Manganese) in it. Bright fiery orange with a slight afterglow.
ZnS:Cu or Ag -- Green lasts awhile.
UO2(NO3)4 glows brilliant green yellow. some very slight after glow.
Quite Radioactive but nice colour.

CaSO4 --- Glows long after exposure to 405nm
MgSiO4:Tb -- Strong afterglow and continues for many days.Greenish/yellow
CaSO4:Eu --- Similar affect as above only Deep Reddish pink.

Sr3.84Eu0.06Dy0.10Al14O25 -- Long afterglow blue-green. (Base material is Strontium Aluminate) Dopants are Europium and Dysprosium.

CaZr4(PO4)6 (Dy) --- 3500K light warm white (used to make warm white LEDs). not much afterglow
 
Last edited:

Benm

Well-known member
Joined
Aug 16, 2007
Messages
8,113
Points
113
I'm not really sure what's going on with that table. I think it was built in the 1970s or 1980s, and have no clue as to where it came from or what varnish was used on it.

But it does phosphoresce green light when swept with 405 nm light. It doesn't last long, it is not interestingly bright, but enough to notice by the naked eye easily when sweeping the dot over it.

I don't suppose it contains any of the minerals mentioned and the effect is due to some organic substance. There really is no way to tell what that might be apart from chipping of a chunk and doing raman spectroscopy on it.

I doubt it's all that interesting though, it's just a plain old table that i got from a used furniture shop a decade ago, and i'm sure there are many more like it out there. If anyone wants to know i'll be happy to donate that table to science, in exchange for a table of similar size and shape ;)
 

steve001

Well-known member
Joined
Jun 3, 2007
Messages
2,515
Points
113
Soda-lime glass. It has an orange after glow after hitting it with 405nm.
Calcite that has trace impurities of Mn (Manganese) in it. Bright fiery orange with a slight afterglow.
ZnS:Cu or Ag -- Green lasts awhile.
UO2(NO3)4 glows brilliant green yellow. some very slight after glow.
Quite Radioactive but nice colour.

CaSO4 --- Glows long after exposure to 405nm
MgSiO4:Tb -- Strong afterglow and continues for many days.Greenish/yellow
CaSO4:Eu --- Similar affect as above only Deep Reddish pink.

Sr3.84Eu0.06Dy0.10Al14O25 -- Long afterglow blue-green. (Base material is Strontium Aluminate) Dopants are Europium and Dysprosium.

CaZr4(PO4)6 (Dy) --- 3500K light warm white (used to make warm white LEDs). not much afterglow

I have some glow powder that glows cyan. I wonder why the few things that I've discovered to glow actually do. I just read that gypsum will glow.
 

Seoul_lasers

Well-known member
Joined
Jul 4, 2008
Messages
2,680
Points
113
I have some glow powder that glows cyan. I wonder why the few things that I've discovered to glow actually do. I just read that gypsum will glow.

You've probably got some one of the more modern Strontium aluminate doped with Eu and Dy. How old is the powder? does the effect last a long time?

I can confirm Gypsum does glow a pale greenish-white and so do some "white" eggs. Only very slightly.

The most surprising was how strong tonic water reacts to 405nm. Tonic water contains Quinine which is UV sensitive. It causes a Cyan fluorescence.
If your tonic water has the hydrochloride salt in it, it will not fluoresce and instead scatter the laser light.
Chlorine ions quench fluorescence of Quinine.
Quinine can also be used in Dye lasers though C20H10Na2O5 and C27H29ClN2O3 are more often used and produce a much stronger output.

below are some examples of materials one could energize with a bluray laser for fun or a project.



 
Last edited:

steve001

Well-known member
Joined
Jun 3, 2007
Messages
2,515
Points
113
You've probably got some one of the more modern Strontium aluminate doped with Eu and Dy. How old is the powder? does the effect last a long time?

I can confirm Gypsum does glow a pale greenish-white and so do some "white" eggs. Only very slightly.

The most surprising was how strong tonic water reacts to 405nm. Tonic water contains Quinine which is UV sensitive. It causes a Cyan fluorescence.
If your tonic water has the hydrochloride salt in it, it will not fluoresce and instead scatter the laser light.
Chlorine ions quench fluorescence of Quinine.
Quinine can also be used in Dye lasers though C20H10Na2O5 and C27H29ClN2O3 are more often used and produce a much stronger output.

below are some examples of materials one could energize with a bluray laser for fun or a project.



Color wise it glows cyan for quite a while. After a point the glow becomes a pale white. It's not old. It think I bought it from glowinc.com. Lots of things floresce, mostly white. What surprised me is how brightly a led floresces.
Something that totally caught me by surprise is the color green plants floresce. Can you guess the color?
 
Last edited:

Seoul_lasers

Well-known member
Joined
Jul 4, 2008
Messages
2,680
Points
113
Color wise it glows cyan for quite a while. After a point the glow becomes a pale white. It's not old. It think I bought it from glowinc.com. Lots of things floresce, mostly white. What surprised me is how brightly a led floresces.
Something that totally caught me by surprise is the color green plants floresce. Can you guess the color?


405nm is exactly what those white/warm white LEDs are pumped with. The LED is actually a InGaN emitter with a phosphor coating on the top to create the white light. CaZr4(PO4)6 (Dy) is what is responsible for 3500K light in LEDs.
Manipulating the formula and adding either Eu, Tb, or Dy in differing amounts shifts the output to pretty much any desired color.
Many green plants fluoresce reddish-pink usually due to the concentrations of C55H72MgN4O5 Chlorophyll A. Not all plants give this fluorescence.
 

steve001

Well-known member
Joined
Jun 3, 2007
Messages
2,515
Points
113
405nm is exactly what those white/warm white LEDs are pumped with. The LED is actually a InGaN emitter with a phosphor coating on the top to create the white light. CaZr4(PO4)6 (Dy) is what is responsible for 3500K light in LEDs.
Manipulating the formula and adding either Eu, Tb, or Dy in differing amounts shifts the output to pretty much any desired color.
Many green plants fluoresce reddish-pink usually due to the concentrations of C55H72MgN4O5 Chlorophyll A. Not all plants give this fluorescence.
I see why led's glow, thanks.
You know. I figured it would be Chlorophyll A. One weed I found floreses brilliantly compare to other plants. For other members who have not seen the color this is close to what the color looks like.
 




Top