Coherent Optical Modulation for Terabit Research Demo

Michael Koenigsmann, application specialist at Keysight Technologies’ Network and Data Center group, presents a groundbreaking solution for coherent terabit research. The innovative setup utilizes the cutting-edge 110 gigahertz optical modulation analyzer (OMA) system and the industry's fastest Arbitrary Waveform Generator to enable testing beyond 100 gigabaud speeds. Central to this solution are the M8190 series of Arbitrary Waveform Generators and the N4391B Optical Modulation Analyzer family.

The setup showcased in the video is designed to mimic a complete coherent transceiver, allowing users to test both transmitter and receiver components. Koenigsmann dives into the specifics of the transmitter setup, highlighting the M8194A 120 gigasample per channel Arbitrary Waveform Generator. The Optical Modulation Generator software, tailored for coherent signal generation, drives the AWG, offering detailed control over waveform definition.

Koenigmann discusses the calibration process, correcting for modulator S-parameters and channel response to ensure a flat frequency response. He shows how to set up waveform generation, including using PRBS encoding and pulse shaping. The setup also allows for adjustments in skew, gain imbalance, and channel mapping, providing flexibility for various testing scenarios.

Koenigmann demonstrates the transmission path from the AWG to the optical modulator, tunable laser source, and through signal conditioning components like couplers, filters, and amplifiers. The signal then enters the Optical Modulation Analyzer, housing a coherent receiver with a built-in local oscillator and optical hybrid.

The optical INQ signals are converted into electrical signals using photodiodes, which are then analyzed by the UXR-Series real-time oscilloscope with up to 110 gigahertz bandwidth. Koenigmann showcases real-time oscilloscope capabilities, displaying QAM-64 constellations, optical signal statistics, and critical parameters such as error vector magnitude, symbol rate, and polarization imbalance.

Furthermore, the video provides insights into spectrum analysis, adaptive equalization for optimized error vector magnitude readings, and bit error measurements. Koenigmann concludes the presentation with an overview of the comprehensive testing capabilities offered by the setup, emphasizing its significance in advancing coherent terabit research.

In conclusion, this video presents a detailed exploration of Keysight Technologies' advanced solution for coherent terabit research, combining state-of-the-art optical modulation and coherent optics technologies. It offers a glimpse into the intricate process of testing and optimizing high-speed optical communications, showcasing the potential for pushing the boundaries of terabit research.