IEC 61977 Ed. 4.0 b:2020

IEC 61977:2020 applies to the family of fibre optic filters. These components have all of 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, i.e. the modification of the spectral intensity distribution is fixed and cannot 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.
They 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 the following: optical, mechanical and environmental properties. This third edition cancels and replaces the second edition published in 2010. It constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- harmonization of a number of terms and definitions with other generic specifications;
- deletion of the quality assessment level clause.
Keywords: fibre optic filters generic specification