Circular core single-mode 3-dimensional crossover polymer waveguides fabricated with the Mosquito method

Area of Science:

• Optoelectronics
• Materials Science
• Photonics

Background:

• Optical interconnects are crucial for high-bandwidth data transmission.
• 3D optical waveguides offer enhanced density and routing capabilities.
• Developing efficient 3D waveguide structures with low loss is essential.

Purpose of the Study:

• To fabricate and characterize novel 3D crossover single-mode polymer optical waveguides.
• To evaluate the performance of these waveguides, focusing on insertion loss and crosstalk.
• To assess the suitability of these waveguides for on-board and inter-chip optical interconnects.

Main Methods:

• Fabrication of circular core 3D crossover single-mode polymer optical waveguides using the photomask-free Mosquito method.
• Creation of a 2x2 channel crossover structure with varying core heights for vertical and horizontal bending.
• Comparison of insertion losses with 3D S-bend waveguides and investigation of crossover-induced loss.

Main Results:

• The fabricated 3D crossover waveguides demonstrated low average insertion losses: 3.95/3.81 dB at 1310 nm and 5.74/4.80 dB at 1550 nm.
• Negligible additional loss was observed due to the core crossover.
• Interchannel crosstalk was below -40 dB, with a 1 dB radial alignment tolerance of ±1.7 µm (1310 nm) and ±2.1 µm (1550 nm).

Conclusions:

• The Mosquito method enables efficient fabrication of 3D crossover polymer optical waveguides.
• These waveguides exhibit excellent optical performance, including low loss and crosstalk.
• The developed waveguides show significant potential for high-bandwidth-density optical interconnects in electronic systems.