Compact substrate-removed thin-film lithium niobate electro-optic modulator featuring polarization-insensitive...

Area of Science:

• Photonics and Optical Engineering
• Materials Science
• Telecommunications Engineering

Background:

• Compact, polarization-insensitive electro-optic (EO) modulators are crucial for 5G and 6G wireless networks.
• Existing EO modulators often struggle with polarization sensitivity, limiting their application in fiber-interconnected systems.

Purpose of the Study:

• To propose and demonstrate a novel polarization-insensitive EO modulator.
• To enable flexible integration of lasers and modulators in advanced wireless communication systems.

Main Methods:

• Fabrication of a modulator using substrate-removed thin-film lithium niobate.
• Experimental characterization of polarization-dependent loss and on-chip loss.
• Demonstration of polarization insensitivity using 50 Gbaud four-level pulse-amplitude modulation.

Main Results:

• The proposed device exhibits a low polarization-dependent loss of 0.35 dB.
• On-chip loss was measured to be approximately 2 dB.
• Experimental validation confirmed polarization insensitivity at 100 Gb/s.

Conclusions:

• The substrate-removed thin-film lithium niobate modulator offers a viable solution for polarization-insensitive modulation.
• This technology supports the high-speed data transmission requirements of future wireless networks.
• The device facilitates remote laser-modulator configurations via standard single-mode fiber.