Wavelength-multiplexed subranging electro-optic modulator (SEOM) for high dynamic range applications

A subranging electro-optic modulator (SEOM) system, comprising:

• a transmitting device;
• the transmitting device including:
• one or more laser devices configured to transmit a plurality of laser beams, each of the plurality of laser beams operating at a different wavelength;
• a plurality of electro-optic modulators, coupled to the one or more laser devices, the one or more laser devices to deliver the plurality of laser beams to the plurality of electro-optic modulators, wherein each of the plurality of electro-optic modulators receives one of the plurality of laser beams;
• one or more bias voltage generators, coupled to the associated one of the plurality of electro-optic modulators, to apply a plurality of voltage bias signals to the associated one of the plurality of electro-optic modulators;
• and
• one or more data devices, coupled to an associated one of the plurality of electro-optic modulators, to apply a data signal to be modulated to the plurality of electro-optic modulators, wherein the plurality of electro-optical modulators are configured to generate an associated plurality of modulated optical signals, based in part on the plurality of voltage bias signals and the different wavelengths of the plurality of laser beams, and wherein an input range of the data signal is captured by a linear portion of a transfer function of the corresponding plurality of electro-optic modulators and a linear portion of a range of the plurality of modulated optical signals is increased due to a number of the corresponding plurality of electro-optic modulators;
• a plurality of optical fibres coupled to an associated one of the plurality of electro-optic modulators, the plurality of electro-optic modulators to transmit the plurality of modulated optical signals to the associated one of the plurality of optical fibres and to a receiving device;
• and
• the receiving device in the SEOM system including:
• a plurality of photodetectors coupled to an associated plurality of optical fibres, the plurality of photodetectors to detect an associated one of the plurality of modulated optical signals;
• a plurality of analog-to-digital converters (ADCs), coupled to the associated plurality of photodetectors, the plurality of ADCs configured to convert the detected plurality of received analog or multi-level modulated optical signals into a plurality of received digital modulated optical signals;
• an amplitude adjusting module configured to adjust an amplitude of each of the plurality of received digital modulated optical signals to compensate for the wavelength dependence of a modulation index and a photodetector response;
• a thresholding module, coupled to the plurality of ADCs, the thresholding module configured to perform a thresholding operation to identify a range between a minimum voltage and a maximum voltage, wherein the range corresponds to a linear portion of the transfer function;
• and
• a splicing or fusing module, coupled to the thresholding module, the splicing or fusing module configured to splice or fuse the plurality of received digital modulated optical signals into a final received optical signal, wherein the final received optical signal spans the linear portion of the transfer function of the corresponding plurality of electro-optic modulators.