Sub-dB/cm propagation loss in silver stripe waveguides

Area of Science:

• Materials Science
• Optoelectronics
• Photonics

Background:

• Polymer-based waveguides are crucial for optical communication.
• Achieving low propagation losses is essential for efficient signal transmission.
• Metal-dielectric waveguides offer potential for high-performance optical components.

Purpose of the Study:

• To demonstrate sub-dB/cm propagation losses in polymer-based silver stripe waveguides.
• To develop a fabrication process for uniform metal stripe patterns.
• To evaluate the performance of these waveguides for optical applications.

Main Methods:

• Fabrication of silver stripe waveguides in a low-loss fluorinated polymer clad.
• Development of a lift-off process using double layers of photoresist and SiNx for uniform metal stripe patterns.
• Characterization of propagation loss and coupling loss at a wavelength of 1.31 microm.

Main Results:

• Achieved propagation losses below 1.0 dB/cm for 11-nm-thick silver stripes (1.5-4.5 microm width).
• Recorded a minimum propagation loss of 0.4 dB/cm for 2.0-microm width stripes.
• Obtained a coupling loss of approximately 1.0 dB with a polarization-maintaining single-mode fiber for 4.5-microm width stripes.

Conclusions:

• Polymer-based silver stripe waveguides can achieve ultra-low propagation losses.
• The developed lift-off process is effective in creating uniform metal stripes essential for low loss.
• These waveguides show potential for integration into advanced optical communication systems, comparable to dielectric waveguides.