Experimental demonstration of a wafer-level flexible probe for optical waveguide testing

Area of Science:

• Photonics and optical engineering.
• Materials science, focusing on polymer waveguides.
• Integrated optics and optoelectronics.

Background:

• Efficient light coupling is crucial for planar lightwave circuit (PLC) performance and packaging.
• Current coupling methods can be inefficient and costly, impacting manufacturing yield.
• Wafer-level processing offers scalability but requires precise optical alignment.

Purpose of the Study:

• To investigate a flexible optical probe for wafer-level directional light coupling.
• To achieve high coupling efficiencies into optical waveguides.
• To assess the potential for cost reduction in PLC packaging.

Main Methods:

• Theoretical investigation using simulations to predict coupling efficiencies.
• Experimental fabrication of a flexible optical probe using SU8 as the waveguide material.
• Testing the probe's coupling performance with an S-shaped test waveguide.

Main Results:

• Simulated coupling efficiencies exceeded 80% across various parameters.
• Experimental coupling efficiency of 11% was achieved with the flexible probe to an S-shaped waveguide.
• This efficiency is presented in comparison to direct butt coupling methods.

Conclusions:

• The flexible optical probe demonstrates potential for efficient wafer-level light coupling.
• The technology could lead to significant improvements in PLC manufacturing yield and cost-effectiveness.
• Further development may streamline PLC packaging and reduce overall production cycles.