Abstract
We present and compare two methods for fabricating grating structures for photonic integrated circuits. The first method uses a two-step electron beam lithography (EBL) and dry etch process, while the second uses direct milling of the grating structures using focused ion beam (FIB) nanofabrication. In both cases 1st order periodic structures with a pitch of 238 nm were successfully positioned adjacent to the ridge waveguide. Using the EBL method, a final grating depth of 10 nm was observed with an estimated coupling coefficient of 40 cm-1. Direct milling using FIB provided grating features milled to a depth of up to 350 nm, achieving maximum coupling strengths of over 200 cm-1.
D. D. John
University of California Santa Barbara
-
12.7 – Regrowth-Free 1st-Order Gratings for Photonic Integrated Circuits using Focused Ion Beam Nanofabrication and Electron Beam Lithography
B. Salmond, Cardiff UniversityThomas Peach, Cardiff UniversityS. Thomas, Cardiff UniversitySara Gillgrass, Cardiff UniversityD. D. John, University of California Santa BarbaraW. J. Mitchell, University College LondonB. J. Thibeault, University of California Santa BarbaraM. J. Wale, University College LondonW. Meredith, Compound Semiconductor Centre Ltd.Peter M. Smowton, Cardiff UniversityD. Read, Cardiff University, University of California Santa BarbaraSamuel Shutts, Cardiff University