关键词: 波导, 传输损耗, 内部散射损耗, 表面散射损耗

Abstract: The propagation losses of straight waveguides based on SOI include mode-field mismatching loss, internal scattering loss and surface scattering loss. In order to study the proportions of the three kinds of the straight waveguide propagation losses, the strip waveguide and rib waveguide with the same width were fabricated, and the propagation losses of the two waveguides were analyzed by simulation and experiment. For the light with wavelength of 1550 nm, measured propagation losses of the strip waveguide and rib waveguide were ?2.4 dB·cm^?1 and ?2.0 dB·cm^?1, respectively, while the loss of an ideal waveguide with the same cross section and neglecting impurity defects and surface roughness was close to zero. As a result, the surface scattering loss of strip waveguide was ?1.42 dB·cm^?1, accounting for 59.2% of the total. The internal scattering loss of strip waveguide was ?0.98 dB·cm^?1, accounting for 40.8% of the total.

Key words: waveguide, propagation loss, internal scatteringloss, surface scattering loss