Silicon Photonics
Yi Zhang, Jing Li, Li He, Tom Baehr-Jones and Michael Hochberg
Electrical Engineering, University of Washington
We have developed a robust process for fabrication of prototype silicon waveguides for 1550 nm photonics. We have demonstrated consistent waveguide loss of ~4 dB/cm over six months. Photonic components developed with this process are being used to better understand fundamental photonic performance, to explore applications such as nonlinear optics and biosensing, and to prototype components prior to fabrication in shared foundry runs through the OPSIS program.
Scanning electron microscope images demonstrating our baseline process, for (a) ridge waveguide and (b) grating coupler.
Box plot showing baseline process consistency of waveguide loss for 400 nm wide ridge waveguides in silicon-on-insulator. These are quartile box plots; the bottom of the box is at the first quartile, the top of the box is at the third quartile, and the line represents the median of the data.
Box plot of waveguide loss for averaging strategies available in the JEOL ebeam writing system: Normal (no averaging), Overlap, and Field Shift, for both linear and curved waveguides. Overlap and Field Shift writing reduce waveguide loss by yielding smoother, less lossy sidewalls to the waveguides.
Box plot of waveguide loss for using 4th (high-speed) and 4th (nanolithography) lens modes of the JBX-6300FS. While 5th lens is slower at writing the waveguides, it provides lower waveguide loss.
Publications:
Electron beam lithography writing strategies for low loss, high confinement silicon optical waveguides. Richard J Bojko, Jing Li, Li He, Tom Baehr-Jones, Michael Hochberg (University of Washington), Yukinori Aida (JEOL USA). J. Vac. Sci. Technol. B, 29 (6), Nov/Dec 2011. [DOI: 10.1116/1.3653266]