An optical interconnection arrangement for transmitting high speed data signals, the arrangement comprising: a transmitting component associated with a first processing node for converting an electrical high speed data signal into an optical data signal; an optical transmission channel coupled to the output of the transmitting component; and a receiving component associated with a second processing node and coupled to the output of the optical transmitting channel for receiving the optical data signal and re-converting the received optical data signal into the original electrical high speed data signal, wherein the transmitting component comprises: a phase alignment element responsive to a plurality of N parallel data signals and an electrical clock signal to create as an output a plurality of parallel, phase-aligned data signals; a first optical modulator responsive to the plurality of N parallel phase-aligned data signals and a continuous wave, CW, optical signal to create a multilevel pulse amplitude modulated, PAM, optical data signal representative of the plurality of N parallel phase-aligned data signals; and a second optical modulator responsive to the electrical clock signal and a CW optical signal to create an optical clock output signal; and the receiving component comprises: a first optical/electrical, O/E, conversion device (8,9) responsive to the received multilevel PAM optical data signal to create an electronic version thereof; a second O/E conversion device (8,9) response to the received optical clock signal to create an electronic version thereof; and an A/D converter responsive to the outputs of the first and second O/E conversion devices to recover the original plurality of N parallel data signals therefrom. a transmitting component associated with a first processing node for converting an electrical high speed data signal into an optical data signal; an optical transmission channel coupled to the output of the transmitting component; and a receiving component associated with a second processing node and coupled to the output of the optical transmitting channel for receiving the optical data signal and re-converting the received optical data signal into the original electrical high speed data signal, wherein the transmitting component comprises: a phase alignment element responsive to a plurality of N parallel data signals and an electrical clock signal to create as an output a plurality of parallel, phase-aligned data signals; a first optical modulator responsive to the plurality of N parallel phase-aligned data signals and a continuous wave, CW, optical signal to create a multilevel pulse amplitude modulated, PAM, optical data signal representative of the plurality of N parallel phase-aligned data signals; and a second optical modulator responsive to the electrical clock signal and a CW optical signal to create an optical clock output signal; and a phase alignment element responsive to a plurality of N parallel data signals and an electrical clock signal to create as an output a plurality of parallel, phase-aligned data signals; a first optical modulator responsive to the plurality of N parallel phase-aligned data signals and a continuous wave, CW, optical signal to create a multilevel pulse amplitude modulated, PAM, optical data signal representative of the plurality of N parallel phase-aligned data signals; and a second optical modulator responsive to the electrical clock signal and a CW optical signal to create an optical clock output signal; and the receiving component comprises: a first optical/electrical, O/E, conversion device (8,9) responsive to the received multilevel PAM optical data signal to create an electronic version thereof; a second O/E conversion device (8,9) response to the received optical clock signal to create an electronic version thereof; and an A/D converter responsive to the outputs of the first and second O/E conversion devices to recover the original plurality of N parallel data signals therefrom. a first optical/electrical, O/E, conversion device (8,9) responsive to the received multilevel PAM optical data signal to create an electronic version thereof; a second O/E conversion device (8,9) response to the received optical clock signal to create an electronic version thereof; and an A/D converter responsive to the outputs of the first and second O/E conversion devices to recover the original plurality of N parallel data signals therefrom.