A method and a protection switching arrangement for protection switching
of any one of a plurality of optical signals of a multi-wavelength
optical signal from the failure of an optical component is provided. The
multi-wavelength optical signal which contains the optical signals is
itself rerouted by the use of wavelength agnostic rerouting elements,
after which a tunable optical filter is used to obtain from the
multi-wavelength optical signal the particular optical signal which would
have been affected by the failure. In embodiments of the invention where
the failed component is a switching fabric, the multi-wavelength optical
signal is rerouted away from the failed switching fabric through a
redundant switching fabric after which the particular optical signal is
obtained with use of the tunable optical filter.