ELECTROCARIAN

Researchers at Australia  are testing a new technology that can allow cell phones to work without needing either cell towers or satellites.   Apple’s iPhone 4 has been recently making  headlines for reception problems caused by its antenna design. But what if there is a software that can let you make and receive phone calls even when there’s no network available. Well, Australian researchers have created just such a software.   Researchers at Flinders University are testing a new technology that uses the WiFi interface that is in almost all phones today, to allow multiple mobiles to create their own, small network. It actually allows mobiles to transmit calls to one another without cell towers or satellites. “The software detects other phones in its WiFi radius, and places calls to them without needing an operator. Obviously, the big challenge for an idea like this is range. At best, a mobile phone will have a WiFi radius of a few hundred feet. And that’s in ideal circumstances – in

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 on the order of the wavelengths of visible light (about 500nm) . Optical layers at this scale can have remarkable properties. These properties can further be enhanced by use of difference in refractive indices between layers, air and substrate. These properties are used to make the ‘Thin Film Optical Filters’ . Thin-film filter is a very accurate colour filter used to selectively pass light of a small range of colours while reflecting other colours. A thin film filter uses the principle of interference. Layers of an optical coating is made on glass substrate. This coating reinforces the certain wavelength and interfere with other wavelengths. By controlling the thickness of coating, we can select the wavelength to be filtered out. The filtered energy is sometimes absorbed by the coating and s