A Six-Section Photonic Integrated Transmitter With Chirp Control for Extension of the Transmission Reach

We demonstrate a novel directly modulated transmitter, based on a six-section photonic integrated circuit. The device uses a unique master-slave configuration with a variable optical attenuator in between, allowing decoupling of cavities and independent control of the injection power. The VOA also provides the ability to find an optimum injection level that balances the trade-off between the extinction ratio and the chirp of the transmitted signal. Using the device, an error-free transmission of a 10 Gb/s non-return-to-zero signal over 25 km and 50 km standard single mode fibre is achieved.