Demultiplexer for optical orthogonal frequency-division multiplexing using an optical fast-Fourier-transform circuit

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Signal Processing

Background:

• Optical orthogonal frequency-division multiplexing (OOFDM) is a key technology for high-capacity optical communication.
• Efficient demultiplexing of OOFDM signals is crucial for advanced optical networks.
• Existing demultiplexing methods often face challenges with complexity, size, and precise filter control.

Purpose of the Study:

• To develop and demonstrate a compact and efficient integrated-optic device for demultiplexing OOFDM signals.
• To utilize an optical fast-Fourier-transform (O-FFT) circuit for precise channel filtering.
• To validate the device's performance in processing high-speed OOFDM data streams.

Main Methods:

• Design and fabrication of an integrated-optic device incorporating an O-FFT circuit and optical gates.
• The O-FFT circuit is constructed using symmetrical Mach-Zehnder interferometers for adjustable filter characteristics.
• Experimental validation using a demultiplexer for four subcarrier channels, processing 4 x 10 Gbit/s OOFDM signals.

Main Results:

• Successful implementation of an integrated-optic demultiplexer with a simplified configuration and reduced footprint.
• Demonstration of precise filter characteristic adjustment using symmetrical Mach-Zehnder interferometers.
• Effective demultiplexing of 4 x 10 Gbit/s OOFDM signals, confirming the device's capability for multi-channel processing.

Conclusions:

• The developed integrated-optic device offers a promising solution for efficient OOFDM signal demultiplexing.
• The use of O-FFT circuits with Mach-Zehnder interferometers provides a scalable and precise approach.
• This technology has the potential to advance high-capacity optical communication systems.