两介质波导的最小中心间距

Minimum Center-to-center Separation of Two Dielectric Waveguides

根据波导的耦合模理论,推导出两介质波导单位长度串扰的表达式,并在一定串扰的前提下,定义了两介质波导最小间距和最小中心间距,提出采用最小中心间距做为衡量波导集成度的参量.分析了波导尺寸及折射率差对最小间距、最小中心间距的影响.分析和模拟结果表明:折射率差越大,两波导最小间距、最小中心间距越小;在大折射率差的条件下,两波导最小间距可以降低到1μm以下;在给定的工作波长、折射率分布的条件下,两介质波导的最小中心间距存在最小值.

Based on the coupled mode theory,analytical expression of crosstalk per unit length between two dielectric waveguides is derived.The minimum separation and center-to-center separation of two dielectric waveguides under certain crosstalk are defined.The minimum center-to-center separation serves as a measure of waveguide integration.The influences of waveguide size and refractive index difference on the minimum center-to-center separation are investigated.The analysis and simulation results indicate that strongly confined waveguides have small minimum separation and center-to-center separation.Under the condition of large refractive index difference,the minimum separation can be reduced to less than 1 μm.The minimum center-to-center separation has a minimum value for given wavelength and refractive index distribution.