Fabrication techniques for grating-based optical devices

We describe a novel, versatile process for fabricating integrated Bragg-grating devices. Our process addresses many of the critical challenges presented by such devices, including period selection, alignment, spatial coherence, and nanolithography. Using a combination of e-beam, x-ray, optical, and interference lithographies, we have successfully employed this process to construct 244 nm period, quarter-wave-shifted Bragg gratings on top of 1-μm-tall waveguide structures in InP.