DIN EN 61977:2010-12

DIN EN 61977 is a generic specification and applies to the family of fibre optic filters. The standard is directed at manufacturers and customers of these products. It gives specifications for classification by various criteria and gives suggestions relating to identification and packaging. The Annex describes various filtering technologies. Fibre optic filters have the following general features: -They are passive for the reason that they contain no optoelectronic or other transducing elements which can process the optical signal launched into the input port; - they modify the spectral intensity distribution in order to select some wavelengths and inhibit others; - they are fixed, that means, the modification of the spectral intensity distribution is fixed and can not be tuned; - they have input and output ports or a common port (having both functions of input and output) for the transmission of optical power; the ports are optical fibre or optical fibre connectors. They differ according to their characteristics and can be divided into the following categories: - short-wave pass (only wavelengths lower than or equal to a specified value are passed); - long-wave pass (only wavelengths greater than or equal to a specified value are passed); - band-pass (only an optical window is allowed); - notch (only an optical window is inhibited). It is also possible to have a combination of the above categories. This standard establishes uniform requirements for optical, mechanical and environmental properties. The standard refers to the standards of the series 61300 (Basic test and measurement procedures). The responsible Committee is Subcommittee UK 412.7 "LWL-Verbindungstechnik und passive optische Komponenten" ("Fibre optic interconnecting devices and passive optical components") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.