Liquid-crystal-based visible-light integrated optical phased arrays and application to underwater communications

Area of Science:

• Photonics
• Optical Engineering
• Materials Science

Background:

• Integrated optical phased arrays (OPAs) are crucial for beam forming and steering.
• Visible-light applications require compact and efficient OPA technologies.

Purpose of the Study:

• To present the first liquid-crystal-based integrated optical phased arrays (OPAs) for visible light.
• To demonstrate their capability for beam forming, steering, and optical communication.

Main Methods:

• Development of a cascaded OPA architecture using liquid crystals.
• Experimental characterization of beam emission at 632.8 nm.
• Demonstration of a visible-light free-space optical communication transmitter.
• Implementation of an underwater wireless optical communication link.

Main Results:

• Achieved a beam with a full width at half maximum of 0.4°×1.6°.
• Demonstrated a 7.2° beam-steering range with ±3.4 V.
• Established a 1-Gbps underwater optical communication link using on-off-keying.
• Showcased an electronically-switchable point-to-multipoint link with >19 dB channel selectivity.

Conclusions:

• Liquid-crystal-based integrated OPAs are viable for visible-light beam forming and steering.
• These OPAs enable novel applications in free-space and underwater optical communications.
• The demonstrated technology offers high performance for wireless optical links.