Total internal reflexion on a polymer

In summary: AGAIN In summary, the engineer is trying to find a way to get more light out of an acrylic panel so that it can be used frontally instead of backlighting. He has found that using a pure 100% glycerine between the artwork and the acrylic panel might help.
  • #1
ramonpujals
6
0
Dear Everyone

I am facing the following engineering problem. I "inject" light in a flat (6.5mm) Acrylic panel at the edges of it. Due the different refractive index of the Acrylic material (1.4) and air (1) 90% of the "injected light" experiments total internal reflexion. I need to get the light out of the Acrylic panel on one of its planes. Pls., see the attachment.
The purpose of this is to light frontally an artwork as oposed to the standard backlighting.

The main problem am facing is that the contact between the artwork and the botton plane of the Acrylic panel is not tight enough. There is air between and total internal reflexion persists, hence the artwork is not illuminated. Is there any material I can place between the artwork and the bottom plane of the Acrylic panel to enhance the contact between them?

I will be glad if anyone can give me some idea.

Be well

Ramon Pujals
Barcelona
 

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  • #2
Try using pure 100% glycerine between artwork and acrylic. Its index of refraction is 1.475, close to lucite (1.50). Its vapor pressure is only 1 mm Hg at 125 deg C. I do not know about solubility/interaction with your artwork. Apply blob near center of acrylic(without bubbles) and use ink roller and fingers behind artwork to squeeze excess and bubbles out to perimeter. Use pressure plate behind artwork to maintain pressure on back of artwork.
[Edit] This optical silicone oil, used for hiding scratches in glass etc., might also work. It has an index of refraction about 1.50.
See http://store.pasco.com/pascostore/showdetl.cfm?&DID=9&Product_ID=56874&groupID=156&Detail=1
[Edit #2] Here is an Acrylic Matching Fluid (matches acrylic index of refraction) from Cargylle (but it is not cheap). It has the viscosity of honey.
http://www.cargille.com/AC5032.pdf
 
Last edited:
  • #3
Dear Bob

THKS a lot. Using a viscose fluid was my first though owin to the need of enhanced contact. But I didnt know glycerine was the appropriate one, big thanks. I have to check the possible interations between the paint of the artwork, as you pointed out.

lets see how it turns out.

THKS
 

Related to Total internal reflexion on a polymer

1. What is total internal reflection on a polymer?

Total internal reflection on a polymer occurs when a light ray traveling through a polymer material reaches the interface between the polymer and another medium with a lower refractive index, causing the light to be completely reflected back into the polymer.

2. How does total internal reflection on a polymer occur?

Total internal reflection on a polymer occurs due to the difference in refractive indices between the polymer material and the surrounding medium. The light ray is reflected back into the polymer because it cannot pass through the interface due to the change in refractive index.

3. What is the critical angle for total internal reflection on a polymer?

The critical angle for total internal reflection on a polymer is the angle at which the light ray is incident on the interface between the polymer and another medium with a lower refractive index. If the angle of incidence is greater than the critical angle, total internal reflection will occur.

4. What factors can affect total internal reflection on a polymer?

The refractive indices of the polymer material and the surrounding medium, as well as the angle of incidence of the light ray, can all affect total internal reflection on a polymer. The thickness and quality of the polymer material can also play a role.

5. What are some practical applications of total internal reflection on a polymer?

Total internal reflection on a polymer has various practical applications, such as in optical fibers for telecommunication and medical imaging devices. It is also used in reflective coatings for sunglasses and laser technology for cutting and welding materials. In addition, it plays a crucial role in enhancing the brightness and contrast in LCD screens and digital displays.

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