A novel transmitter architecture for combined baseband data and subcarrier-multiplexed control links using differential Mach-Zehnder external modulators

We propose, analyze, and demonstrate a novel transmitter architecture for links that support transmission of base-band data and subcarrier multiplexed control channels. The architecture utilizes a differential external integrated-optic modulator to electrooptically combine the base-band and subcarrier multiplexed data onto an optical carrier. An analytical model is presented that allows optimization of the SNR of the received base-band and control data channels based on modulation parameters. This optimization is based on tradeoffs that result when the base-band and subcarrier channel are combined using a nonlinear modulator transfer function. We experimentally demonstrate a link based on this architecture with 2.5-Gb/s base-band and 100-Mb/s control data multiplexed on a 5.5-GHz subcarrier. Analytical and measured experimental results are compared and are shown to be in good agreement.