@article { Wang:15, title = {Design of broadband subwavelength grating couplers with low back reflection}, journal = {Optics Letters}, volume = {40}, number = {20}, year = {2015}, month = {10/2015}, pages = {4647--4650}, publisher = {OSA}, type = {article}, abstract = {We present a methodology to design broadband grating couplers using one-dimensional subwavelength gratings. Using the presented method, we design subwavelength grating couplers (SWGCs) with 1-dB bandwidths ranging from 50 to 90\&\#xA0;nm. Our designed SWGCs have competitive coupling efficiency, as high as \&\#x2212;3.8\&\#x2009;\&\#x2009;dB for the fundamental TE mode, and state-of-the-art back reflections, as low as \&\#x2212;23\&\#x2009;\&\#x2009;dB.}, keywords = {Gratings; Effective medium theory ; Subwavelength structures}, URL = {http://ol.osa.org/abstract.cfm?URI=ol-40-20-4647}, author = { Wang, Yun and Shi, Wei and Wang, Xu and Lu, Zeqin and Caverley, Michael and Bojko, Richard and Chrostowski, Lukas and Jaeger, Nicolas A. F. } }