Sodium Vapor Lamps are some of the most efficient lamps in the world. They have an efficiency of up to 190 lumens per watt compared to an incandescent street lamp which has between 15 and 19 lumens per watt.
By William Wassmer
24 Jul 2013
The hydrogen fluoride (HF) laser is an infrared chemical laser that combines hydrogen produced in a combustion chamber with fluorine gas produced by thermal decomposition of compounds to create excited HF molecules.
A lens can be described as an optical device that transmits and refracts the incident beam by converging or diverging it. A simple lens consists of a single optical element, while a compound lens is an array of simple lenses arranged in such a way that they have a common axis.
Dichroic filters are filters that optic filters that are placed at an angle of 45° to the light source, causing the light to travel in a different direction. Dichroic is a Greek word meaning bicoloured.
Optical bandpass filters are filters that allow only a certain bandwidth of light and block the others above and below the specified bandwidth.
An optical diffuser can be defined as an element that scatters light. An optical diffuser is used for softening or giving shape to an illumination. Optical diffusers are commonly used in commercial photography.
Brillouin scattering may be described as a phenomenon of inelastic scattering of light in a physical medium brought about by thermally excited acoustical phonons. Brillouin scattering is usually observed in solid medium.
Raman amplification is a phenomenon in non-linear optical mediums where the transfer of power from one optical beam to another happens when it is downshifted in frequency by the energy from an optical phonon.
Indium Gallium Nitride (InGaN) laser is a semiconductor laser. It is also called blue laser as the emitted wavelength of light is perceived as blue colour by the human eye. InGaN is essentially a semiconductor material, which is a mix of gallium nitride (GaN) and indium nitride (InN).
An international research team led by the Paris Observatory has developed an optical atomic clock based on strontium.
By Will Soutter
10 Jul 2013