The resonance characteristics of the micro-coil resonator(MCR) with different turns and coupling conditions are presented, which show that the effective length of the MCR with small coupling coefficient at primary resonant is independent of the turns, and the resonance dips always appear in pairs corresponding to multiple critical-coupling because of the periodicity of coupling strength. However, complicated resonance is observed in an MCR with larger coupling coefficient and turns. The superluminal or subluminal propagation regime can be obtained respectively by adjusting the coupling condition, and the effect of loss on them in different coupling conditions is investigated. There is such a loss threshold in the critical-coupling and over-coupling conditions, near which the group refractive index abrupt changes between positive and negative extremum, and the threshold is increased by 105 orders of magnitude under over-coupling condition compared with critical-coupling. In view of the transmission near a resonant evolve not only with the detuning of transmission phase, but also drastically with the adjustment of coupling condition which will be modulated by the cladding refractive index and coupling length. Hence a potential sensitivity enhancement for biochemical and inertial sensing based on MCR is also investigated briefly.

中文翻译：

---

基于微光纤的微线圈谐振器中的反常光传播和电位灵敏度增强


给出了不同匝数和耦合条件的微线圈谐振器（MCR）的谐振特性，结果表明，耦合系数小的MCR在初级谐振时的有效长度与匝数无关，并且谐振谷总是出现在初级谐振处。由于耦合强度的周期性，对应于多个临界耦合的对。然而，在具有较大耦合系数和匝数的MCR中观察到复杂的谐振。通过调节耦合条件可以分别获得超光速或亚光速传播区域，并研究了不同耦合条件下损耗对它们的影响。在临界耦合和过耦合条件下存在这样一个损耗阈值，在该阈值附近群折射率在正极值和负极值之间突变，并且过耦合条件下该阈值比临界耦合条件提高了105个数量级。耦合。鉴于谐振附近的传输不仅随着传输相位的失谐而演变，而且随着耦合条件的调整而急剧变化，耦合条件将由包层折射率和耦合长度调制。因此，还简要研究了基于 MCR 的生化和惯性传感的潜在灵敏度增强。