Optical LiNbO(3) 3-branched waveguide and its application to a 4-port optical switch

Area of Science:

• Photonics and Waveguide Technology
• Materials Science in Lithium Niobate
• Optical Switching Devices

Background:

• Optical waveguides are crucial for integrated photonics.
• Lithium niobate (LiNbO3) is a key material for electro-optic devices.
• Efficient light routing and switching are essential for optical networks.

Purpose of the Study:

• To experimentally and theoretically investigate a 3-branched optical waveguide in Ti-diffused Z-cut LiNbO3.
• To demonstrate selective light feeding into multiple waveguide branches.
• To propose and fabricate components for a 4-port optical switch.

Main Methods:

• Fabrication of a Ti-diffused Z-cut LiNbO3 waveguide with three branches.
• Experimental application of voltage to control light distribution.
• Theoretical analysis of waveguide behavior.
• Fabrication of bent waveguides using Nb2O5/Ti:LiNbO3 for switch integration.

Main Results:

• Selective light feeding into three branches was achieved.
• An extinction ratio of nearly 10 dB was obtained at +/-25 V.
• A 4-port optical switch design integrating 3-branched and bent waveguides was proposed.
• Bent waveguides with a 0.5-mm radius of curvature were successfully fabricated.

Conclusions:

• The 3-branched waveguide in LiNbO3 offers effective control over light distribution.
• The demonstrated performance is suitable for optical switching applications.
• The integrated approach using bent waveguides advances the development of compact optical switches.