A system for transmitting an optical signal using a plurality of wavelength bands, each wavelength band including a plurality of channels, the system comprising: a traffic distribution circuit (202, 216) configured to distribute traffic to a plurality of WDM modules; a first module coupled to the traffic distribution circuit and comprising: a first plurality of tunable optical transmitters, each transmitter associated with a different wavelength band of the plurality of wavelength bands and tuned to transmit optical signals in a first channel included within the associated wavelength band of the transmitter; and a first multiplexer coupled to the first plurality of transmitters and configured to combine the optical signals transmitted from the first plurality of transmitters into a first optical signal comprising the plurality of wavelength bands; a second WDM module coupled to the traffic distribution circuit and comprising: a second plurality of tunable optical transmitters, each transmitter associated with a different wavelength band of the same plurality of wavelength bands associated with the first WDM module and tuned to transmit optical signals in a second channel included within the associated wavelength band of the transmitter; and a second multiplexer coupled to the second plurality of transmitters and configured to combine the optical signals transmitted from the second plurality of transmitters into a second optical signal comprising the same plurality of wavelength bands associated with the first WDM module; and a cyclic multiplexer coupled to the first and second WDM modules and configured to combine the first and second optical signals into an optical output signal. a traffic distribution circuit (202, 216) configured to distribute traffic to a plurality of WDM modules; a first module coupled to the traffic distribution circuit and comprising: a first plurality of tunable optical transmitters, each transmitter associated with a different wavelength band of the plurality of wavelength bands and tuned to transmit optical signals in a first channel included within the associated wavelength band of the transmitter; and a first multiplexer coupled to the first plurality of transmitters and configured to combine the optical signals transmitted from the first plurality of transmitters into a first optical signal comprising the plurality of wavelength bands; a second WDM module coupled to the traffic distribution circuit and comprising: a second plurality of tunable optical transmitters, each transmitter associated with a different wavelength band of the same plurality of wavelength bands associated with the first WDM module and tuned to transmit optical signals in a second channel included within the associated wavelength band of the transmitter; and a second multiplexer coupled to the second plurality of transmitters and configured to combine the optical signals transmitted from the second plurality of transmitters into a second optical signal comprising the same plurality of wavelength bands associated with the first WDM module; and a cyclic multiplexer coupled to the first and second WDM modules and configured to combine the first and second optical signals into an optical output signal. a first plurality of tunable optical transmitters, each transmitter associated with a different wavelength band of the plurality of wavelength bands and tuned to transmit optical signals in a first channel included within the associated wavelength band of the transmitter; and a first multiplexer coupled to the first plurality of transmitters and configured to combine the optical signals transmitted from the first plurality of transmitters into a first optical signal comprising the plurality of wavelength bands; a second WDM module coupled to the traffic distribution circuit and comprising: a second plurality of tunable optical transmitters, each transmitter associated with a different wavelength band of the same plurality of wavelength bands associated with the first WDM module and tuned to transmit optical signals in a second channel included within the associated wavelength band of the transmitter; and a second multiplexer coupled to the second plurality of transmitters and configured to combine the optical signals transmitted from the second plurality of transmitters into a second optical signal comprising the same plurality of wavelength bands associated with the first WDM module; and a second plurality of tunable optical transmitters, each transmitter associated with a different wavelength band of the same plurality of wavelength bands associated with the first WDM module and tuned to transmit optical signals in a second channel included within the associated wavelength band of the transmitter; and a second multiplexer coupled to the second plurality of transmitters and configured to combine the optical signals transmitted from the second plurality of transmitters into a second optical signal comprising the same plurality of wavelength bands associated with the first WDM module; and a cyclic multiplexer coupled to the first and second WDM modules and configured to combine the first and second optical signals into an optical output signal.