Ultralow-loss 3-dB photonic crystal waveguide splitter

Area of Science:

• Photonics
• Integrated Optics
• Nanophotonics

Background:

• Photonic crystal waveguides offer unique light manipulation capabilities.
• Efficient power splitting is crucial for integrated photonic circuits.
• Achieving ultralow loss in splitters remains a key challenge.

Purpose of the Study:

• To design and fabricate a high-performance 3-dB photonic crystal waveguide splitter.
• To achieve ultralow insertion loss for TE-polarized light.
• To validate experimental results with accurate theoretical modeling.

Main Methods:

• Fabrication of a silicon-on-insulator photonic crystal waveguide splitter using deep UV lithography.
• Design optimization incorporating a Y junction for single-mode operation and low-loss 60-degree bends.
• Experimental characterization of the splitter's performance, including insertion loss and splitting ratio.
• Three-dimensional finite-difference time-domain (FDTD) modeling for theoretical validation.

Main Results:

• Fabrication of a photonic crystal waveguide splitter with ultralow-loss 3-dB splitting for TE-polarized light.
• Experimental demonstration of zero-loss 3-dB output in the wavelength range of 1560-1585 nm.
• Excellent agreement between experimental measurements and 3D FDTD simulations without adjustable parameters.

Conclusions:

• The developed photonic crystal waveguide splitter achieves state-of-the-art performance in terms of low loss and accurate splitting.
• The design, utilizing a Y junction and optimized bends, effectively ensures single-mode operation and minimizes losses.
• The study validates the efficacy of deep UV lithography and FDTD modeling for advanced photonic device development.