High-efficiency broadband out-of-plane fiber-to-polymer waveguide grating coupler.

Area of Science:

• Photonics
• Materials Science
• Optical Engineering

Background:

• Polymer photonics offers broad applications and wavelength transparency.
• Wafer-scale testing of polymer waveguides is hindered by low-index contrast.
• Efficient light coupling is crucial for integrated photonic devices.

Purpose of the Study:

• To demonstrate an amorphous silicon-based out-of-plane grating coupler for polymer waveguides.
• To address challenges in wafer-scale testing of polymer photonic devices.
• To achieve efficient and broadband light coupling between optical fibers and polymer waveguides.

Main Methods:

• Utilized amorphous silicon for grating coupler fabrication.
• Designed and simulated an out-of-plane grating coupler structure.
• Experimentally coupled light from a single-mode optical fiber to a polymer waveguide.

Main Results:

• Simulated maximum coupling efficiency of -1.13 dB.
• Simulated 1 dB bandwidth of 95 nm over the C-L-band.
• Experimentally measured peak coupling efficiency of -2.15 dB per coupler.
• Experimentally measured 1 dB and 3 dB bandwidths of 49 nm and 89 nm, respectively.

Conclusions:

• The amorphous silicon grating coupler is a viable solution for efficient light coupling in polymer waveguides.
• The demonstrated device facilitates wafer-scale testing and integrated photonic applications.
• The grating coupler exhibits broadband performance suitable for optical communication.