Multi-wavelength coherent transmission using an optical frequency comb as a local oscillator

Area of Science:

• Optical Communications
• Photonics
• Signal Processing

Background:

• Increasing data rates necessitate spectrally efficient coherent transmission.
• Optical frequency combs (OFC) are precise multi-wavelength sources for WDM transmission.

Purpose of the Study:

• To demonstrate the use of OFCs as scalable multi-wavelength local oscillators (LO) for coherent detection.
• To leverage OFC advantages at the receiver for enhanced WDM systems.

Main Methods:

• Utilized a pair of synchronized OFCs for WDM transmission and intradyne reception.
• Employed gain-switched, injection-locked semiconductor lasers for OFC generation.
• Synchronized receiver comb to transmitter, maintaining intradyne frequencies below 15 MHz.

Main Results:

• Achieved 1.104 Tbit/s aggregate line rate (1.032 Tbit/s net data rate) over 10 km standard single mode fiber.
• Demonstrated 13 WDM channels with a spectral efficiency of 5.16 bit/s/Hz.
• Maintained low intradyne frequencies for all data channels.

Conclusions:

• This work presents the first demonstration of coherent WDM transmission using synchronized OFCs at both the transmitter and receiver.
• The findings highlight the potential of OFCs for scalable, high-capacity optical communication systems.