Subwavelength grating metamaterial waveguides functionalized with tellurium oxide cladding.

Area of Science:

• Integrated Optics
• Materials Science
• Nanophotonics

Background:

• Subwavelength grating metamaterial waveguides are crucial for advanced photonic integrated circuits.
• High-index cladding materials are needed to enhance waveguide performance and enable new functionalities.

Purpose of the Study:

• To design, fabricate, and characterize novel subwavelength grating metamaterial waveguides.
• To investigate the use of tellurium oxide as a high-index cladding material for these waveguides.
• To evaluate the impact of tellurium oxide cladding on propagation loss and operating regimes.

Main Methods:

• Fabrication using CMOS-compatible processes on a silicon-on-insulator platform.
• Deposition of amorphous tellurium oxide via RF magnetron sputtering.
• Characterization of photonic bandstructure and propagation loss.

Main Results:

• Achieved a propagation loss of 1.0 ± 0.1 dB/mm with tellurium oxide cladding, compared to 1.5 ± 0.1 dB/mm for silicon dioxide.
• Demonstrated control over photonic bandstructure, enabling subwavelength propagation, slow light, and photonic bandgap regimes.
• Successfully implemented a high-index (n > 2) oxide cladding for subwavelength grating metamaterial waveguides.

Conclusions:

• Tellurium oxide is a promising high-index cladding material for subwavelength grating metamaterial waveguides.
• This work introduces a new material platform for on-chip integrated optics with improved performance.
• The developed waveguides are suitable for various applications within the 1550 nm telecommunications window.