|
Thin-film Optics
Thin-film optics is the branch of optics that deals with very thin structured layers of different materials. In order to exhibit thin-film optics, the thickness of the layers of material must be similar to the coherence length; for visible light it is most often observed between 200 and 1000 nm of thickness. Layers at this scale can have remarkable reflective properties due to light wave interference and the difference in refractive index between the layers, the air, and the substrate. These effects alter the way the optic reflects and transmits light. This effect, known as thin-film interference, is observable in soap bubbles and oil slicks. More general periodic structures, not limited to planar layers, exhibit structural coloration with more complex dependence on angle, and are known as photonic crystals. In manufacturing, thin film layers can be achieved through the deposition of one or more thin layers of material onto a substrate (usually glass). This is most oft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dichroic Filters
A dichroic filter, thin-film filter, or interference filter is a color filter used to selectively pass light of a small range of colors while reflecting other colors. By comparison, dichroic mirrors and dichroic reflectors tend to be characterized by the colors of light that they reflect, rather than the colors they pass. Dichroic filters can filter light from a white light source to produce light that is perceived by humans to be highly saturated in color. Such filters are popular in architectural and theatrical applications. Dichroic reflectors known as cold mirrors are commonly used behind a light source to reflect visible light forward while allowing the invisible infrared light to pass out of the rear of the fixture. Such an arrangement allows intense illumination with less heating of the illuminated object. Many quartz-halogen lamps have an integrated dichroic reflector for this purpose, being originally designed for use in slide projectors to avoid melting the slides, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass
Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) of the molten form; some glasses such as volcanic glass are naturally occurring. The most familiar, and historically the oldest, types of manufactured glass are "silicate glasses" based on the chemical compound silica (silicon dioxide, or quartz), the primary constituent of sand. Soda–lime glass, containing around 70% silica, accounts for around 90% of manufactured glass. The term ''glass'', in popular usage, is often used to refer only to this type of material, although silica-free glasses often have desirable properties for applications in modern communications technology. Some objects, such as drinking glasses and eyeglasses, are so commonly made of silicate-based glass that they are simply called by the name of the material. Despite bei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lawes's Parotia
Lawes's parotia (''Parotia lawesii''), is a medium-sized (up to 27 cm long) passerine of the bird-of-paradise family, Paradisaeidae. It is distributed and endemic to mountain forests of southeast and eastern Papua New Guinea. Occasionally, the eastern parotia is considered a subspecies of ''P. lawesii''. The species is similar to the western parotia (''Parotia sefilata''). Like most birds of paradise, male Lawes's parotia are polygamous. The few eggs that have been studied were about 33 x 24 mm in size, but these were possibly small specimens. It eats mainly fruit, seeds and arthropods. The bird's home was discovered by Carl Hunstein on a mountain near Port Moresby in 1884. Its name honors the New Guinea pioneer missionary Reverend William George Lawes. Widespread and common throughout its range, Lawes's parotia is evaluated as Least Concern on the IUCN Red List of Threatened Species. It is listed on Appendix II of CITES. Description The male is a velvet black b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graphium Sarpedon
''Graphium sarpedon'', the common bluebottle or blue triangle in Australia, is a species of swallowtail butterfly that is found in South and Southeast Asia, as well as eastern Australia. There are approximately sixteen subspecies with differing geographical distributions. Description Upperside opaque black. Forewings and hindwings crossed from above the tornal area on the hindwing to near the apex of the forewing by a semi- hyaline broad pale blue medial band which is broadest in the middle, more or less greenish and macular anteriorly; the portion of the band that crosses interspaces 6, 7 and 8 on the hindwing white; beyond the band on the hindwing there is a sub-terminal line of blue slender lunules. Underside similar, ground colour dark brown. Hindwing: a short comparatively broad sub-basal band from costa to sub-costal vein, and the postdiscal area between the medial blue band and the sub-terminal lunules velvety black traversed by the pale veins and transversely, exce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aglais Io
''Aglais io'', the European peacock, more commonly known simply as the peacock butterfly, is a colourful butterfly, found in Europe and temperate Asia as far east as Japan. It was formerly classified as the only member of the genus ''Inachis'' (the name is derived from Greek mythology, meaning Io, the daughter of Inachus). It should not be confused or classified with the "American peacocks" in the genus '' Anartia''; while belonging to the same family as the European peacock, Nymphalidae, the American peacocks are not close relatives of the Eurasian species. The peacock butterfly is resident in much of its range, often wintering in buildings or trees. It therefore often appears quite early in spring. The peacock butterfly has figured in research in which the role of eyespots as an anti-predator mechanism has been investigated. The peacock is expanding its range and is not known to be threatened. Characteristics The butterfly has a wingspan of 50 to 55 mm. The base colour o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
