Lu Tsan-Wen, Lin Pin-Tso, Sio Kuan-Un, Lee Po-Tsung
Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Rm. 415 CPT Building, 1001 Ta Hsueh Road, Hsinchu 300, Taiwan.
Opt Express. 2010 Feb 1;18(3):2566-72. doi: 10.1364/OE.18.002566.
We propose a point-shifted nanocavity based on square lattice photonic crystal, which sustains a lowest-order whispering-gallery (WG) mode. In simulation, the optimized WG mode (quality (Q) factor approximately 14,000) in point-shifted nanocavity can be with smaller mode volume (approximately 5.5(lambda/2n)(3)) but larger nano-post tolerance than those in single-defect cavity design. From well-fabricated device, single WG mode lasing with measured Q factor of 4,100 and low threshold of 160 microW is obtained. Besides, we also observe the changed polarization of WG mode due to modal symmetry breaking caused by the presence of a nearby dielectric nano-particle, which would be useful in sensing molecule binding or attaching for bio-chemical applications.
我们提出了一种基于方形晶格光子晶体的点移纳米腔，它支持最低阶回音壁（WG）模式。在模拟中，点移纳米腔中优化后的WG模式（品质（Q）因子约为14000）相比于单缺陷腔设计，具有更小的模式体积（约为5.5(λ/2n)³）和更大的纳米柱容差。通过制作精良的器件，获得了单WG模式激光，其测量的Q因子为4100，阈值低至160微瓦。此外，我们还观察到由于附近存在介电纳米粒子导致模态对称性破坏，WG模式的偏振发生了变化，这在生物化学应用中用于传感分子结合或附着方面将是有用的。
