Poly(methyl methacrylate)
Poly(methyl methacrylate) (PMMA) is the synthetic polymer derived from methyl methacrylate. It is used as an engineering plastic, and it is a transparent thermoplastic. PMMA is also known as acrylic, acrylic glass, as well as by the trade names and brands Crylux, Hesalite, Plexiglas, Acrylite, Lucite, and Perspex, among several others. This plastic is often used in sheet form as a lightweight or shatter-resistant alternative to glass. It can also be used as a casting resin, in inks and coatings, and for many other purposes.
Lichtenberg figure: high-voltage dielectric breakdown in an acrylic polymer block
Pieces of Plexiglas®, the windscreen of a German plane shot down during World War II
Close-up of pressure sphere of the bathyscaphe Trieste, with a single conical window of PMMA set into sphere hull. The very small black circle (smaller than the man's head) is the inner side of the plastic "window", only a few inches in diameter. The larger circular clear black area represents the larger outer side of the thick one-piece plastic cone "window".
10-meter (33-foot) deep Monterey Bay Aquarium tank has acrylic windows up to 33 centimeters (13 inches) thick to withstand the water pressure.
Transparency and translucency
In the field of optics, transparency is the physical property of allowing light to pass through the material without appreciable scattering of light. On a macroscopic scale, the photons can be said to follow Snell's law. Translucency allows light to pass through, but does not necessarily follow Snell's law; the photons can be scattered at either of the two interfaces, or internally, where there is a change in index of refraction. In other words, a translucent material is made up of components with different indices of refraction. A transparent material is made up of components with a uniform index of refraction. Transparent materials appear clear, with the overall appearance of one color, or any combination leading up to a brilliant spectrum of every color. The opposite property of translucency is opacity. Other categories of visual appearance, related to the perception of regular or diffuse reflection and transmission of light, have been organized under the concept of cesia in an order system with three variables, including transparency, translucency and opacity among the involved aspects.
Dichroic filters are created using optically transparent materials.
Translucency of a material being used to highlight the structure of a mushroom
A laser beam bouncing down an acrylic rod, illustrating the total internal reflection of light in a multimode optical fiber
Experimentally measured record low attenuation of silica core optical fiber. At 1550 nm wavelength attenuation components are determined as follows: Rayleigh scattering loss ~ 0.1200 dB/km, infrared absorption loss ~ 0.0150 dB/km, impurity absorption loss ~ 0.0047 dB/km, waveguide imperfection loss ~ 0.0010 dB/km.