Characterization of the focusing waveguide grating coupler using near-field scanning optical microscope

초록

The focusing characteristics of focusing waveguide grating coupler were measured by near-field scanning optical microscope. By scanning NSOM probe, the diffraction pattern and the intensity distribution were observed at the neighbor of the coupler surface and at the focal plane, respectively. In addition, it was confirmed that the beam spot could be dramatically reduced by placing solid immersion lens on the coupler plane.