Zhong Qiuhang, Tian Zhaobing, Dastjerdi M Hadi Tavakoli, Mi Zetian, Plant David V
Department of Electrical and Computer Engineering, McGill University, Montréal, QC, H3A 2A7, Canada.
Opt Express. 2013 Aug 12;21(16):18909-18. doi: 10.1364/OE.21.018909.
We report on theoretical and experimental investigation of azimuthal and longitudinal modes in rolled-up microtubes at telecom wavelengths. These microtubes are fabricated by selectively releasing a coherently strained InGaAs/GaAs bilayer. We apply planar waveguide method and a quasi-potential model to analyze the azimuthal and longitudinal modes in the microtubes near 1550 nm. Then we demonstrate these modes in transmission spectrum by evanescent light coupling. The experimental observations agree well with the calculated results. Surface-scattering-induced mode splitting is also observed in both transmission and reflection spectra at ~1600 nm. The mode splitting is in essence the non-degeneracy of clockwise and counter-clockwise whispering-gallery modes of the microtubes. This study is significant for understanding the physics of modes in microtubes and other microcavities with three-dimensional optical confinement, as well as for potential applications such as microtube-based photonic integrated devices and sensing purposes.
我们报告了在电信波长下对卷起的微管中的方位角模式和纵向模式进行的理论和实验研究。这些微管是通过选择性释放相干应变的InGaAs/GaAs双层来制造的。我们应用平面波导方法和准势模型来分析微管中接近1550 nm处的方位角模式和纵向模式。然后，我们通过倏逝光耦合在透射光谱中展示了这些模式。实验观察结果与计算结果吻合良好。在~1600 nm的透射和反射光谱中也观察到了表面散射引起的模式分裂。这种模式分裂本质上是微管顺时针和逆时针回音壁模式的非简并性。这项研究对于理解微管和其他具有三维光学限制的微腔中的模式物理，以及对于基于微管的光子集成器件和传感用途等潜在应用具有重要意义。
