Liquid-crystal-on-silicon-based optical add/drop multiplexer for orbital-angular-momentum-multiplexed optical links

Area of Science:

• Optoelectronics
• Optical Communications
• Photonics

Background:

• Orbital-angular-momentum (OAM) multiplexing offers a promising approach for increasing data transmission capacity in optical networks.
• Existing methods for managing OAM-multiplexed beams can be complex and inefficient.
• The unique ring-shaped intensity profile of OAM beams presents opportunities for novel device designs.

Purpose of the Study:

• To design and demonstrate an optical add/drop multiplexer specifically for OAM-multiplexed data links.
• To enable the selective addition or removal of individual OAM beams within a multiplexed stream.
• To evaluate the performance of the designed multiplexer in terms of data integrity and signal loss.

Main Methods:

• Utilized the inherent ring-shaped intensity profile of OAM beams for device operation.
• Employed liquid-crystal-on-silicon (LCOS)-based diffraction optical elements to manipulate OAM beams.
• Integrated the LCOS elements into an optical add/drop multiplexer architecture.

Main Results:

• Successfully demonstrated the addition and dropping of a single OAM beam from a stream of three multiplexed OAM beams.
• Achieved a low power penalty of less than 2 dB for 100 Gbit/s quadrature phase-shift-keying (QPSK) data.
• Maintained a bit-error rate (BER) of 2.0×10(-3) for each channel, indicating high data integrity.

Conclusions:

• The developed optical add/drop multiplexer is effective for managing OAM-multiplexed data links.
• The use of LCOS-based diffraction optical elements provides a viable solution for OAM beam manipulation.
• The demonstrated performance metrics suggest the technology's potential for future high-capacity optical communication systems.