A wavelength routing cross-connect (1, 21, 101) comprising: a first input section connectable to a first input fiber (3, 23, 103) for receiving a first WDM input signal comprising a plurality of wavelength channels and a first input Wavelength Blocker (2, 22, 102) having an input connected to the first input section for receiving the first WDM optical signal, the first wavelength blocker being configured to selectively block or pass each wavelength channel of the first WDM optical signal in order to select a subset of the wavelength channels of the first WDM optical signal as a function of a configuration state, a second input section connectable to a second input fiber (3, 23, 103) for receiving a second WDM input signal comprising a plurality of wavelength channels and a second input Wavelength Blocker (2, 22, 102) having an input connected to the second input section for receiving the second WDM optical signal, the second wavelength blocker being configured to selectively block or pass each wavelength channel of the second WDM optical signal in order to select a subset of the wavelength channels of the second WDM optical signal as a function of a configuration state, a star coupler (11, 31, 111) having a plurality of inputs connected to the respective input wavelength blockers for receiving the subsets of wavelength channels of each WDM input signal selected by the respective input Wavelength Blockers, the star coupler comprising optical paths to transparently pass a combination of the selected subsets of wavelength channels of the first and the second WDM optical signals to a plurality of star coupler outputs, a first output section connectable to a first output fiber (4, 24, 104), a second output section connectable to a second output fiber (4, 24, 104), a first output Wavelength Blocker (14, 34, 114) arranged between a first star coupler output and the first output section and configured to selectively block or pass each wavelength channel of the combination of the subsets of wavelength channels of the first and second WDM optical signals as a function of a configuration state, and a second output Wavelength Blocker (14, 34, 114) arranged between a second star coupler output and the second output section, and configured to selectively block or pass each wavelength channel of the combination of the subsets of wavelength channels of the first and second WDM optical signals as a function of a configuration state. a first input section connectable to a first input fiber (3, 23, 103) for receiving a first WDM input signal comprising a plurality of wavelength channels and a first input Wavelength Blocker (2, 22, 102) having an input connected to the first input section for receiving the first WDM optical signal, the first wavelength blocker being configured to selectively block or pass each wavelength channel of the first WDM optical signal in order to select a subset of the wavelength channels of the first WDM optical signal as a function of a configuration state, a second input section connectable to a second input fiber (3, 23, 103) for receiving a second WDM input signal comprising a plurality of wavelength channels and a second input Wavelength Blocker (2, 22, 102) having an input connected to the second input section for receiving the second WDM optical signal, the second wavelength blocker being configured to selectively block or pass each wavelength channel of the second WDM optical signal in order to select a subset of the wavelength channels of the second WDM optical signal as a function of a configuration state, a star coupler (11, 31, 111) having a plurality of inputs connected to the respective input wavelength blockers for receiving the subsets of wavelength channels of each WDM input signal selected by the respective input Wavelength Blockers, the star coupler comprising optical paths to transparently pass a combination of the selected subsets of wavelength channels of the first and the second WDM optical signals to a plurality of star coupler outputs, a first output section connectable to a first output fiber (4, 24, 104), a second output section connectable to a second output fiber (4, 24, 104), a first output Wavelength Blocker (14, 34, 114) arranged between a first star coupler output and the first output section and configured to selectively block or pass each wavelength channel of the combination of the subsets of wavelength channels of the first and second WDM optical signals as a function of a configuration state, and a second output Wavelength Blocker (14, 34, 114) arranged between a second star coupler output and the second output section, and configured to selectively block or pass each wavelength channel of the combination of the subsets of wavelength channels of the first and second WDM optical signals as a function of a configuration state.