Sciencemadness Discussion Board

Novelty/Interesting ways of generating continuous light?

Junk_Enginerd - 24-9-2020 at 11:36

I couldn't tell you why, but I have this fascination with lamps. Not just any lamps, but lamps that don't work like everyday lamps. And usually, if I'm fascinated by something there's at least one person out there who is as well...

What are some interesting ways of generating(continuous) light? Doesn't have to be much, I'm mostly looking for the decorative aspect of it.

I've made a few small lamps based on fluorescence, getting the fluorescence from vitamins (riboflavin is the fluorescent one, yeah?), using glass tubes as optical conductors and UV LEDs in water filled bulbs. Pretty cool and alien result.

I'm thinking a chemistry forum ought to contain people who know all kinds of odd ways of generating light.

I've yet to try making a discharge lamp or arc lamp, but I intend to get there eventually. Would be really interesting to try other elements than commonly seen, like noble gases, look like. Maybe a sulfur discharge lamp? Or a potassium lamp? Just need to spend some time making a decent general purpose discharge lamp driver...

Fyndium - 24-9-2020 at 12:50

Could UV lasers be used in UV light catalyzed reactions? The laser beam could be lead into the vessel through a column instead through the glass, because afaik soda and boro filters off the high energy UV light, and this way this filtering would be actually beneficial because now it prevents it from exiting the vessel.

Pulsed and high energy lasers are what interest me. I've got a couple of the lower end handheld devices, 1W blue laser being the most powerful one.

Light production from laser

MadHatter - 24-9-2020 at 16:58

Maybe a little off topic but I found this article from a blog at
cartelligent.com very interesting.


February 10, 2016

Automobile headlights have evolved significantly in the past
several years from the incandescent beams of the past to halogens to LEDs. Laser headlights, which were first introduced in the BMW i8, take this even further providing a brilliant white light to illuminate the road ahead.

BMW says that laser headlights can be up to 1,000 times brighter than an LED while consuming significantly less power. They can also light up to 6 times more road than traditional LED low beams, providing significantly increased visibility.


How do laser headlights work?
The first thing to understand is that laser headlights don’t actually shoot laser beams at the road ahead. Instead, three blue lasers fire their beams onto a set of mirrors. The mirrors then focus the energy into a lens filled with yellow phosphorus which in turn emits an intense white light. The reflected light from these beams is safe to be looked at directly.

Fyndium, I have a 30 watt, blue(450 nm) laser. I can light my cigarettes with it. :D:D:D

Herr Haber - 24-9-2020 at 17:55

Carbide lamps give the best light to appreciate your surroundings.

clearly_not_atara - 25-9-2020 at 05:34

Cadmium-gallium arc lamp?

https://nvlpubs.nist.gov/nistpubs/ScientificPapers/nbsscient...

Beware of the toxicity of Cd.

concerning lasers

organichem - 25-9-2020 at 14:28

Currently I am doing some work in a laserlab where the research group also needs some white-light continuum and therefore uses a Ti:sapphire-laser that emits light with 800 nm. The frequency is then doubled to 400 nm and shot onto a rotating crystal of CaF2. Over some nonlinear optical processes there is produced the wanted white-light continuum: [img]https://www.researchgate.net/profile/Ivan_Buchvarov/publication/223648356/figure/fig2/AS:341363829821441@1458398887034/Spectra-of-the-white-light -continuum-pulses-generated-in-CaF-2-LiF-and-MgF-2-crystal_W640.jpg[/img]

One can also use other optical non-linear substances like sapphire, MgF2, LiF, etc. DOI: 10.1016/S0030-4018(02)01107-0

Junk_Enginerd - 26-9-2020 at 00:30

Quote: Originally posted by clearly_not_atara  
Cadmium-gallium arc lamp?

https://nvlpubs.nist.gov/nistpubs/ScientificPapers/nbsscient...

Beware of the toxicity of Cd.


That was a really cool read. Back when scientific reports actually made sense, at least to a layman like me.

Though there's one big thing I'm not understanding here. There's that nice figure of the distillation setup and the capillary that gets sealed off... but I don't understand what actually makes the lamp in the end. I would expect it to be the "bulb", which the alloy is being distilled into, but that part doesn't have electrodes. Is the alloy being distilled out of the lamp, with the intent to only leave a tiny amount behind?

Chemetix - 26-9-2020 at 01:09

I think I might have to try the cadmium lamp. Although I'll use a quartz halogen tube with it's modern molybdenum seals rather than the old fashioned lead tungsten capillary.
Reading the exhaustive process of purifying the gallium, it almost feels like I'm cheating with the vial of four 9's galllium sitting in my desk drawer.

unionised - 26-9-2020 at 08:50

If you are thinking of trying it, could you do a simple experiment for me; try using tin in place of gallium.
It also has a low melting point , will soften the cadmium and has a low vapour pressure.
It's also a good deal cheaper than gallium.

Junk_Enginerd - 27-9-2020 at 00:48

Quote: Originally posted by Chemetix  
I think I might have to try the cadmium lamp. Although I'll use a quartz halogen tube with it's modern molybdenum seals rather than the old fashioned lead tungsten capillary.
Reading the exhaustive process of purifying the gallium, it almost feels like I'm cheating with the vial of four 9's galllium sitting in my desk drawer.


Haha yeah, the part about the gallium was fascinating. "The little known element gallium" like it was an exotic artifact from a distant kingdom. I bet that's exactly what it was, but still cool to get a glimpse of the time when what we now consider pretty basic stuff to be so unknown.

Are you saying halogen bulbs are quartz glass? That's very interesting if it's the case. Also, why the metal seals at all? I thought encasing a tungsten wire in molten glass was a good enough seal for any purpose?

[Edited on 27-9-2020 by Junk_Enginerd]

Quote: Originally posted by unionised  
If you are thinking of trying it, could you do a simple experiment for me; try using tin in place of gallium.
It also has a low melting point , will soften the cadmium and has a low vapour pressure.
It's also a good deal cheaper than gallium.


Seems unlikely it would work... I'm not basing that on chemistry knowledge, but rather that the author must have been aware of tin and dismissed it for some reason. Tin was hardly exotic after all.

[Edited on 27-9-2020 by Junk_Enginerd]