We present an ultra-compact strip to slot waveguide mode converter to facilitate excellent fundamental mode coupling between the strip and slot waveguide over a broad wavelength range. The design utilizes tapered waveguide geometries for adiabatic mode conversion. The taper profiles are optimized using a fast quasi-adiabatic approach to achieve the adiabatic mode conversion within the smallest possible length. We numerically demonstrate a conversion efficiency of 99.4% at a wavelength 1.55 μ m with a variation of <1.5% over a bandwidth of 100 nm and <5% over a bandwidth of 200 nm. In addition, the design is ultra-compact with a footprint of only 1.23 × 3.7 μ m 2 and offers a high tolerance to the possible fabrication inaccuracies.

中文翻译：

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使用快速准绝热方法的高效带隙缝隙波导模式转换器

我们提出了一种超紧凑的带隙缝隙波导模式转换器，以促进宽波长范围内的带隙缝隙与狭缝波导之间出色的基本模式耦合。该设计利用锥形波导几何形状进行绝热模式转换。使用快速准绝热方法优化锥度轮廓，以在最小可能的长度内实现绝热模式转换。我们以数值方式证明了在波长1.55μm处的转换效率为99.4％，在100 nm带宽上的变化率<1.5％，在200 nm带宽上的变化率<5％。此外，该设计非常紧凑，占地面积仅为1.23  ×  3.7μm 2，并且对可能的制造误差具有很高的容忍度。