A system comprising: a polarization state aligner, PSA, comprising: an input port; a first polarization beam splitter, PBS, coupled to the input port; a first phase shifter, PS, coupled to the first output of the first PBS; a first polarization rotator, PR, coupled to the second output of the first PBS; a first beam splitter, BS, coupled to the first PS and the first PR; a first output port coupled to the first BS; and characterized by a second output port coupled to the first BS, a receiver coupled to the PSA and comprising: a second PBS; a first 90 ° hybrid mixer coupled to the first output of the second PBS and the first output port of the first BS; first photodiodes, PDs, coupled to the first 90° hybrid mixer; first transimpedance amplifiers, TIAs, coupled to the first PDs; and a digital signal processor, DSP, coupled to the first TIAs, wherein the receiver further comprises: a second PR coupled to the second output of the second PBS; a second 90° hybrid mixer coupled to the second PR and the second output port of the first BS; second PDs coupled to the second 90° hybrid mixer; and second TIAs coupled to the second PDs and the DSP. a polarization state aligner, PSA, comprising: an input port; a first polarization beam splitter, PBS, coupled to the input port; a first phase shifter, PS, coupled to the first output of the first PBS; a first polarization rotator, PR, coupled to the second output of the first PBS; a first beam splitter, BS, coupled to the first PS and the first PR; a first output port coupled to the first BS; and characterized by a second output port coupled to the first BS, an input port; a first polarization beam splitter, PBS, coupled to the input port; a first phase shifter, PS, coupled to the first output of the first PBS; a first polarization rotator, PR, coupled to the second output of the first PBS; a first beam splitter, BS, coupled to the first PS and the first PR; a first output port coupled to the first BS; and characterized by a second output port coupled to the first BS, a receiver coupled to the PSA and comprising: a second PBS; a first 90 ° hybrid mixer coupled to the first output of the second PBS and the first output port of the first BS; first photodiodes, PDs, coupled to the first 90° hybrid mixer; first transimpedance amplifiers, TIAs, coupled to the first PDs; and a digital signal processor, DSP, coupled to the first TIAs, a second PBS; a first 90 ° hybrid mixer coupled to the first output of the second PBS and the first output port of the first BS; first photodiodes, PDs, coupled to the first 90° hybrid mixer; first transimpedance amplifiers, TIAs, coupled to the first PDs; and a digital signal processor, DSP, coupled to the first TIAs, wherein the receiver further comprises: a second PR coupled to the second output of the second PBS; a second 90° hybrid mixer coupled to the second PR and the second output port of the first BS; second PDs coupled to the second 90° hybrid mixer; and second TIAs coupled to the second PDs and the DSP. a second PR coupled to the second output of the second PBS; a second 90° hybrid mixer coupled to the second PR and the second output port of the first BS; second PDs coupled to the second 90° hybrid mixer; and second TIAs coupled to the second PDs and the DSP.