Continuously apodized fiber-to-chip surface grating coupler with refractive index engineered subwavelength structure

• DOI: 10.1364/ol.35.003243
• Publication Date: 2010-09-24T16:08:53Z
• Authors: R. Halir; P. Cheben; J. H. Schmid; R. Ma; D. Bedard; S. Janz; D.-X. Xu; A. Densmore; J. Lapointe; Í. Molina-Fernández
• Keywords: Apodization; Integrated Optics

We demonstrate a fully etched, continuously apodized fiber-to-chip surface grating coupler for the first time (to our knowledge). The device is fabricated in single-etch step and operates with TM-polarized light, achieving coupling efficiency of 3.7dB 3dB bandwidth 60nm. A subwavelength microstructure employed to generate an effective medium engineered vary strength thereby maximize efficiency, while mitigating backreflections at same time. Minimum feature size 100nm compatibility deep-UV 193nm lithography.