Broadband etching-free metal grating couplers embedded in titanium dioxide waveguides

Area of Science:

• Photonics and optical engineering
• Materials science for optoelectronics

Background:

• Efficient light coupling is crucial for integrated photonic devices.
• Titanium dioxide is a promising material for optical applications due to its high refractive index and transparency.

Purpose of the Study:

• To propose and experimentally validate metal grating couplers integrated into a titanium dioxide layer.
• To assess the performance of these couplers in terms of coupling efficiency and bandwidth.
• To demonstrate their application in high-speed optical signal transmission.

Main Methods:

• Fabrication of metal grating couplers embedded within a titanium dioxide thin film.
• Experimental characterization of coupling efficiency and 3 dB bandwidth.
• Testing of the couplers for error-free data transmission of wavelength multiplexed signals.

Main Results:

• Experimental coupling efficiency exceeding 20% was achieved.
• A 3 dB bandwidth of 86 nm was demonstrated, consistent with simulations.
• Successful error-free transmission of 10 Gbit/s wavelength multiplexed signals in the C-band was performed.

Conclusions:

• Metal grating couplers integrated into titanium dioxide offer high performance for optical coupling.
• The demonstrated efficiency and bandwidth support practical applications in high-speed optical communication systems.
• This technology provides a viable solution for efficient light manipulation in photonic integrated circuits.