An optical add/drop multiplexer comprising: a first input for receiving a wavelength division multiplexed, WDM, trunk signal from a trunk path, said trunk signal comprising trunk signal utilized channels and trunk signal unutilized channels [510, 520, 540, 550]; a second input for receiving a WDM branch signal from a branch path [152, 162], said branch signal comprising branch signal utilized channels and branch signal unutilized channels [510, 530, 540, 550], at least one of said branch signal utilized channels corresponding to at least one of said trunk signal unutilized channels [510, 520, 540, 550], and at least one of said trunk signal utilized channels corresponding to at least one of said branch signal unutilized channels [510, 530, 540, 550]; a first band-pass filter configured to receive said trunk signal and to selectively remove at least one band of trunk channels from said trunk signal in response to a command signal to provide a first band pass filtered signal, said band of trunk channels comprising a plurality of said trunk signal utilized channels or a plurality of said trunk signal unutilized channels [510, 520, 540, 550]; a second band-pass filter configured to receive said branch signal and to selectively remove at least one band of branch channels from said branch signal in response to the command signal to provide a second band pass filtered signal, said band of branch channels comprising a plurality of said branch signal utilized channels or a plurality of said branch signal unutilized channels [510, 530, 540, 550]; and at least one coupler coupled to the first band-pass filter and the second band pass filter and configured to receive said first and second band pass filtered signals and provide a WDM output signal comprising said at least one trunk signal utilized channel, said at least one branch signal utilized channel, and loading signals on all unutilized channels [510, 540, 550] of said WDM output signal. a first input for receiving a wavelength division multiplexed, WDM, trunk signal from a trunk path, said trunk signal comprising trunk signal utilized channels and trunk signal unutilized channels [510, 520, 540, 550]; a second input for receiving a WDM branch signal from a branch path [152, 162], said branch signal comprising branch signal utilized channels and branch signal unutilized channels [510, 530, 540, 550], at least one of said branch signal utilized channels corresponding to at least one of said trunk signal unutilized channels [510, 520, 540, 550], and at least one of said trunk signal utilized channels corresponding to at least one of said branch signal unutilized channels [510, 530, 540, 550]; a first band-pass filter configured to receive said trunk signal and to selectively remove at least one band of trunk channels from said trunk signal in response to a command signal to provide a first band pass filtered signal, said band of trunk channels comprising a plurality of said trunk signal utilized channels or a plurality of said trunk signal unutilized channels [510, 520, 540, 550]; a second band-pass filter configured to receive said branch signal and to selectively remove at least one band of branch channels from said branch signal in response to the command signal to provide a second band pass filtered signal, said band of branch channels comprising a plurality of said branch signal utilized channels or a plurality of said branch signal unutilized channels [510, 530, 540, 550]; and at least one coupler coupled to the first band-pass filter and the second band pass filter and configured to receive said first and second band pass filtered signals and provide a WDM output signal comprising said at least one trunk signal utilized channel, said at least one branch signal utilized channel, and loading signals on all unutilized channels [510, 540, 550] of said WDM output signal.