FarbigeWelt wrote: ↑
Mon Mar 25, 2019 2:49 pm
Very interesting information. Indeed one can observe emission based on visible excitation. Blue LED should do the trick.
As much I understood the article, in the short time reding, emission due to excitation around 535 nm should be rather faint in optical degree glasses. But a good crystal wine glass may shine in blue LED light with about 430 nm.
Well, it is stuff like this that really gets me started, so naturally I have done it immediately...
Test setup consists of:
- A wine glas (Not good old crystal, but at least I had some new and unused ones, so no wine stains affecting the result)
- An achromatic lens, made of two unknown glass types (OPTI*Media achromat 2-lens, f=280,1mm for anyone interested)
- A white LED room light
- Blue LED light from a fixture mounted above, illuminating a large part of the room.
- A Laserpointer with 405 +- 10 nm (according to the label, but it is one of these cheap ones that should really be forbidden, so who knows)
- A black background, but the rest of the room is a normal lving room, so expect visible reflections on the glass
First, an image of the wine glass under white LED light for reference:
Second, the wine glass under blue LED light:
No fluorescence is visible. Reflections from the background are quite dominant, so this would have to be done in a large, black room with directed light, which I can't set up quite so easily.
Next, placing the lens beside it:
Again, nothing visible immediately, so lets add a laser:
Now we can see something, lets get a closer look:
We can see that one component produces strong, green fluorescence, the other maybe scatters? Lets get a cross-section profile:
It actually seems more like fluorescence with red emission rather than green. Maybe some scatter in addition, hard to say without a spectrometer.
Lets take a look at the wine glass again, shining the laser through the handle:
Now the wine glass also shows green fluorescence. You can't see this in the top-part of the glass (where you pour the wine in), because the glass is too thin and you only see the spot on the surface.
I tried also with green and red lasers, I only get some scatter with them.
And lastly, you can use this to create some nice effects in the foot:
(Note that the laser was mounted in place, so the streaks are not from my hand shaking, that is the uneven surface of the glass!)
So I would conclude: Fluorescence is indeed negliglible, unless you want to render some very specific situations, possibly involving lasers.
P.S.: Sorry for going a bit off-topic again