摘要:
针对单光子源对高性能纳米腔的需要,采用"柔性束缚"光子限制结构和时域有限差分法,通过把时域和频域的光电场分布与理想高斯函数进行比较,设计出一种高品质因子的光子晶体缺三腔(L3),其Q值达2.8×10~5,有效模式体积为V_(eff)=0.1813(λ/n)~9,相应的Purcell因子超过F=1.2×10~5.此外,提出一种定量描述腔性能优劣程度的能量系数分析法,通过定量对比二维高斯分布下的场分布能量与总能量,提高了腔的优化速度与准确性.计算结果表明,随着腔性能的优化,Q值正比于能量系数γ值直至饱和.
Abstract:
A new double-heterostructure photonic crystal L3 microcavity is designed,under the condition of "gentle confinement",the quality factor of the cavity is optimized to reach as high as 2.8×10~5 by comparing the simulated mode distribution calculated by finite difference time domain algorithm with the ideal Gaussian distribution,while the mode volume remains small,V_(eff) = 0.1813(λ/n)~3. This is the best result at present.Additionally,an energy correlation coefficient is introduced to qualitatively describe the optimization level of a photonic crystal microcavity,which improves the speed and the accuracy of optimization.