I need to find a substance which will react to a certain frequency of light

Does anyone know of a substance which will do this please?
Ideally it should initially be clear and then when it comes into contact with a certain frequency of light it should solidify or change colour.

Any links etc would be extremely helpful.
Thanks ;-)
Q

Originally posted by qmantoo
Does anyone know of a substance which will do this please?
Ideally it should initially be clear and then when it comes into contact with a certain frequency of light it should solidify or change colour.

Any links etc would be extremely helpful.
Thanks ;-)
Q

If the particular frequency you're looking for happens to hit a common fluorescence band, you might be in luck, what's the nm?

Interesting question.
The initial substance would let the light pass through it.
Once irradiated it would either absorb all the visible light or reflect it or both.
Do you want a black surface or a mirror surface?
I don't have an answer for you unfortunately.
I'm assuming that the incident electromagnetic radiation would have to change the chemical properties of this substance.
Do you want the substance to revert back to transparent when the electromagnetic radiation is not bombarding it?

reply to post by qmantoo


There is this

en.wikipedia.org...

But that utilizes a voltage to change the property from transparent to opaque.

reply to post by qmantoo


There are many things available that do what you require.

Probably the cheapest and most widely available are dynamic UV tints used on spectacles/sunglasses.

As the UV luminosity increases, so does the darkness of the tint.

There are other ways to tint windows digitally. The modern system being employed on skyscrapers use thin LCD like structures that will tint (rise time is

An LCD,perhaps?

www.cpidaylighting.com...

Or maybe this?

en.wikipedia.org...

reply to post by qmantoo


If you could find out what substance they use in self-darkening sunglasses i think u'd be on the right track.

Though i haven't got a clue what substance that might be

Originally posted by Romekje
reply to post by qmantoo

 

If you could find out what substance they use in self-darkening sunglasses i think u'd be on the right track.

Though i haven't got a clue what substance that might be

The glass in the lenses contain silver halide crystals embedded in a glass substrate. From an article...

In the presence of UV-A light (wavelengths of 320–400 nm), electrons from the glass combine with the colorless silver cations to form elemental silver. Because elemental silver is visible, the lenses appear darker. Back in the shade, this reaction is reversed. The silver returns to its original ionic state, and the lenses become clear.

I might be able to help but first I must ask a few questions to gauge the nature of your experiment.

-Are you a mad scientist?
-Are you making things out of household items?
-Is this application for a doom ray? Frankenstein monster?
-Is what your doing illegal in 39 states?
-Are you wearing the right protective gear? Goggles? latex living gloves?


I find your request intriguing and it's forced me to dig in the ole notebook from college. I'll let you know if I find what your looking for. Is this for bending light to produce results or are you looking at a more direct laser type approach?

Oh I know, your making xray glasses aren't you? Sneaky...very sneaky

reply to post by qmantoo


It really depends on what frequency you want to use and what you want it to do. There are lots of substances that react to about any frequency there is, so without the purpose of it, it's a little difficult to answer the question

Thats for all the comments.

The original question was posed because I was wondering how could create a 3D image of something be generated. The thought came to mind that if you had lasers at right angles to each other. where they crossed could easily be a 'dot' of colour/black and in this way you could create a 3D (kind of holographic) image from 2x 2D images projected into the medium from the sides by a red and green laser.

I was sitting looking at a square glass flower vase which could be filled with this clear liquid and the lasers shone in from each side and either focused (can lasers be focused on a point?) or where they meet at a point in the clear liquid would then turn into a coloured/black spot or dot the size of the combined lasers. If you could do this quickly and then wipe out the image, you could have a moving image in this 3D medium.

Very similar to the way that a LCD uses an x-axis and a y-axis electrical voltage to produce a dark cell where they two cross which goes to form the pixel/character on the LCD.

I really dont know if this has been done - probably it has and I have been living under a stone with no technology news for the last few years. :-)

I do not have the knowledge or circumstances to do this myself, but someone out there may want to play about with the idea and take it further.

reply to post by qmantoo


Sorry. But is has already been done.

Medical science has lasers that can focus on a small point in three dimensional space.

Several lasers, each send part of the wavelength required and at the foci the lasers converge to form a complete wave at one localized point.

Unfortunately, for a 3d image......we need a medium on which to display it. In the past smoke has been used, as well as vacuum chambers filled with certain combinations of noble gases (argon, neon, etc).

If you can find a way to display a 3d image in normal atmosphere.........You would instantly be one very rich person.

It is good to know that medicine has laser beams which can be focused on a specific minute point in space, so now we just have to identify the medium to use. If the focused laser beam part can be done, how about actually burning a spot where the lasers join? That would produce a 'black' spot which would show up in a clear medium.

Medical science has lasers that can focus on a small point in three dimensional space.
Several lasers, each send part of the wavelength required and at the foci the lasers converge to form a complete wave at one localized point.
Unfortunately, for a 3d image......we need a medium on which to display it. In the past smoke has been used, as well as vacuum chambers filled with certain combinations of noble gases (argon, neon, etc).

Yes, I did not think my 'idea' was necessarily unique at all. However, there is always room for a unique application of one technology using technology from a different area or discipline.

This was why I was trying to get us to think about a medium which would react to different frequencies of light so by mixing up a concoction of this substance, we might be able to get a liquid or solid-ish solid where we could produce points where the laser beam had been focused.

You never know, someone may work in an industry where they use this technology for a different application and could see a way that it could be utilised for this.

I think this comes close to what you describe. The medium you seek seems to be plain air.

It produces dots in mid air by laser. It's infant tech - like monochrome computer screens were back in the 80's. I can see this take off big somewhere in the future.

Qmantoo the fukushima Image legend Cool thread!

This similar to what you describe in operation and the closest existing technology I know of. Like the above but multiple lasers. Military has some much cooler stuff as well.




From what I remember it involves lasers focused into points and even ionising the air, using multiple xy scanning systems. Fastest scanners commercially available are around 120,000 points per second within 8 degrees of arc, thermoelectrically cooled and driven with huge currents. Some systems are capable of adjustable divergence, which means they can be focused anywhere along the beam within optical/atmospheric limits, similar to the laser boeing uses on its airborne anti missile platform. They use atmospheric lensing to achieve this and a pilot beam to measure the input required for this effect. There is also an anti mosquito system operating on a similar principle, with infra red lasers, purely experimental and not safe or feasible for home use without eye protection.
Some laser enthusiasts have designed 'anti balloon auto popping' laser systems too

True industrial and lab grade, class 4 visible lasers are stupidly bright with mid air beams. The smallest of floating particles reflect very brightly, like diamonds. The air appears filthy, there is so much visible stuff floating around in it under those circumstances.

I have now moved to somewhere where I can see these Youtubes, and they are amazing. Thanks for posting links to them both. The technology shown is kind-of an active technology where the points are brighter that the surroundings due to the laser beams being focused. This is fine for moving hologram type images and there is lots of potential for improvement by science.

I am assuming that people like Sony and IBM are developing something similar to solve the next generation of memory storage too.

Thank you all for your input. It is good to know we are on the way with this technology.