On-Chip, Single-Shot Characterization of GHz-Rate Complex Optical Signals

Phase reconstruction based on optical ultrafast differentiation is implemented using an integrated-waveguide Mach-Zehnder interferometer to demonstrate self-referenced phase characterization of gigahertz-rate complex modulated signals (e.g., quadrature phase shift keying and amplitude phase shift keying modulation formats), through a single-shot and real-time technique. This method is transparent to both modulation format and bit rate, limited only by the bandwidth capabilities of the temporal intensity measurement instrumentation.