Optimization of a 42.7 Gb/s wavelength tunable RZ transmitter using a linear spectrogram technique

Area of Science:

• Optical communications engineering
• Photonics and optoelectronics
• High-speed data transmission

Background:

• Wavelength tunable transmitters are essential for flexible optical networks.
• Electro-absorption modulators (EAMs) and tunable lasers are key components in these systems.
• Consistent performance across the C-band is a significant challenge for optical systems.

Purpose of the Study:

• To optimize a wavelength tunable RZ transmitter for long-haul optical transmission.
• To investigate the impact of EAM drive and bias conditions on transmission performance.
• To achieve reliable 42.7 Gb/s data transmission over 1500 km independent of operating wavelength.

Main Methods:

• Utilized a linear spectrogram-based characterization technique.
• Optimized radio frequency (RF) drive and DC bias conditions for the EAM.
• Tailored the pulse chirp of the transmitter to match the transmission link's dispersion map.

Main Results:

• Achieved 1500 km transmission at 42.7 Gb/s independent of operating wavelength.
• Demonstrated that varying EAM RF drive and bias conditions at each wavelength is necessary for optimal performance.
• Showed that optimized EAM conditions lead to consistent transmission across a wide wavelength range.

Conclusions:

• Optimizing EAM drive and bias conditions is critical for consistent performance in wavelength tunable transmitters.
• Failure to optimize these parameters results in significant degradation of system performance.
• The linear spectrographic technique effectively characterizes and enables chirp tailoring for improved optical transmission.