Non-destructive and non-contact measurement of semiconductor optical waveguide using optical coherence tomography with a visible broadband light source

We demonstrated non-destructive and non-contact measurement of semiconductor optical waveguide using optical coherence tomography with a visible broadband light source (vis-OCT). Vis-OCT can provide high axial and lateral resolutions of less than 1 mu m. which were effective for measurement of optical waveguides with several-micrometer structure. We obtained cross-sectional images of ridge-type optical waveguides (RWGs) fabricated as test samples and measured the height and width of the RWGs. The height and width measured by vis-OCT were similar to these values measured by scanning electron microscopy. These results indicated that vis-OCT enables measurement of the height and width of optical waveguides without destruction and contact, which is a useful inspection method for high-quality and high-efficiency integrated optical device fabrications. (C) 2018 The Japan Society of Applied Physics