Optical waveguide intersections without light leak.

Area of Science:

• Photonics and Optical Engineering
• Materials Science

Background:

• Optical waveguide intersections are crucial components in integrated photonic circuits.
• Conventional intersections often suffer from significant light leakage and signal loss.
• Minimizing losses at waveguide junctions is essential for efficient optical signal routing.

Purpose of the Study:

• To propose and demonstrate a novel on-level optical waveguide intersection design.
• To achieve zero light leakage and minimal signal loss at the intersection point.
• To investigate the impact of refractive index modulation on waveguide intersection performance.

Main Methods:

• Fabrication of the optical waveguide intersection using photopolymerization with double exposure at the intersection.
• Engineering a higher refractive index (~1%) at the intersection compared to the waveguides (~0.5%).
• Experimental measurement of optical losses in the proposed and conventional intersections.

Main Results:

• The proposed waveguide intersection exhibited very low optical losses.
• Conventional intersections with equal refractive indices showed large leak losses.
• Experimental loss measurements closely matched theoretical calculations.

Conclusions:

• The proposed waveguide intersection design effectively suppresses light leakage and reduces signal loss.
• Photopolymerization offers a viable method for fabricating such high-performance optical components.
• This design presents a significant advancement for developing efficient on-chip optical networks.