Optical equalizer

A method of optical equalisation of an optical signal comprising a plurality of wavelengths, for use in an optical communications system, comprising the steps of:

• filtering the optical signal transmitted by said optical element in the optical communications system through a plurality of concatenated, fixed modulation depth, periodic filters, each having an output which varies periodically with wavelength;
• and
• dynamically wavelength tuning each of said filters in order to optimise optical equalisation of said optical signal by equalizing signal strength across the plurality of wavelengths.

An optical amplifier including an amplifying element and an optical equaliser comprising a plurality of concatenated, fixed modulation depth, periodic filters, each having an output which varies periodically With wavelength, each of which is dynamically wavelength tunable in order to optimise the optical equalisation of an optical signal comprising a plurality of wavelengths and transmitted by said amplifying element by equalizing signal strength across the plurality of wavelengths.

An optical communications system including an optical equaliser comprising a plurality of concatenated, fixed modulation depth, periodic filters, each having an output which varies periodically with wavelength, each of which is individually dynamically wavelength tunable in order to optimise optical equalisation of an optical signal transmitted by an optical element in the optical communications system by equalizing signal strength across the plurality of wavelengths.