Lee K K, Lim D R, Kimerling L C, Shin J, Cerrina F
Opt Lett. 2001 Dec 1;26(23):1888-90. doi: 10.1364/ol.26.001888.
We demonstrate 0.8-dB/cm transmission loss for a single-mode, strip Si/SiO(2) waveguide with submicrometer cross-sectional dimensions. We compare the conventional waveguide-fabrication method with two smoothing technologies that we have developed, oxidation smoothing and anisotropic etching. We observe significant reduction of sidewall roughness with our smoothing technologies, which directly results in reduced scattering losses. The rapid increase in the scattering losses as the waveguide dimension is miniaturized, as seen in conventionally fabricated waveguides, is effectively suppressed in the waveguides made with our smoothing technologies. In the oxidation smoothing case, the loss is reduced from 32 dB/cm for the conventional fabrication method to 0.8 dB/cm for the single-mode waveguide width of 0.5 microm . This is to our knowledge the smallest reported loss for a high-index-difference system such as a Si/SiO(2) strip waveguide.
我们展示了一种具有亚微米级横截面尺寸的单模条形硅/二氧化硅波导，其传输损耗为0.8分贝/厘米。我们将传统的波导制造方法与我们开发的两种平滑技术——氧化平滑和各向异性蚀刻进行了比较。我们观察到，使用我们的平滑技术可显著降低侧壁粗糙度，这直接导致散射损耗降低。在传统制造的波导中，随着波导尺寸的缩小，散射损耗会迅速增加，而在采用我们的平滑技术制造的波导中，这种情况得到了有效抑制。在氧化平滑的情况下，对于传统制造方法，损耗为32分贝/厘米，而对于宽度为0.5微米的单模波导，损耗降至0.8分贝/厘米。据我们所知，这是诸如硅/二氧化硅条形波导等高折射率差系统所报道的最小损耗。
