Apodized and un-apodized sidewall grating filters with low coupling constants in ultra-low-loss Si3N4 planar waveguides. - Michael Belt; Martijn J. R. Heck; Jonathon S. Barton; Jared F. Bauters; John E. Bowers 001; Daniel J. Blumenthal (OFC/NFOEC, 2013)