Integrated multi-channel photonics transmitter chip having variable power dividers

An integrated transmitter chip comprising:

• four input ports disposed at a first end of the integrated transmitter chip;
• a transmitter block optically connected to each input port of the four input ports,
• each transmitter block having:
• a first variable power divider optically connected to the corresponding input port;
• a second variable power divider and a third variable power divider being optically branched from the first variable power divider, such that the first, second and third variable power dividers are arranged in a cascading formation having two cascading stages, wherein the first, second and third variable power dividers each have a corresponding splitting ratio;
• a first and second optical channel being optically branched from the second variable power divider;
• a third and fourth optical channel being optically branched from the third variable power divider;
• and
• four wavelength division multiplexers optically connected to the transmitter blocks, each wavelength division multiplexer having:
• a first multiplexing subunit optically connected to two corresponding optical channels and configured to multiplex two corresponding optical signals into a first combined optical signal;
• a second multiplexing subunit optically connected to two corresponding optical channels and configured to multiplex two corresponding optical signals into a second combined optical signal;
• and
• a polarization rotator and beam combiner optically connected to the first multiplexing subunit and the second multiplexing subunit, the polarization rotator and beam combiner being configured to rotate the polarization of the second combined optical signal while combining the first combined optical signal and the second combined optical signal into a corresponding output optical signal.