Efficient broadband silicon-on-insulator grating coupler with low backreflection.

We design and fabricate an efficient broadband grating coupler on a 400nm thick silicon-on-insulator wafer. The measured coupling loss is 3 dB when coupling to a single-mode fiber at 1310nm wavelength with TE polarization. The spectral FWHM and backreflection are determined to be 58nm and -27 dB, respectively. (C) 2011 Optical Society of America