Yao Ruizhe, Lee Chi-Sen, Podolskiy Viktor, Guo Wei
Opt Express. 2018 Nov 12;26(23):30588-30595. doi: 10.1364/OE.26.030588.
Parity-time (PT) symmetry breaking in counterintuitive gain/loss coupled waveguide designs is numerically and theoretically investigated. The PT symmetry mode selection conditions are determined theoretically. Single-transverse-mode broadband InAs quantum dot (QD) superluminescent light emitting diodes (SLEDs) are fabricated and characterized; the PT symmetric broad-area SLEDs contain laterally coupled gain and loss PT- symmetric waveguides. Single-transverse-mode operation is achieved by parity-time symmetry breaking. The broadband SLEDs exhibit a uniform Gaussian-like emission spectrum with the 3-dB bandwidth of 110 nm. Far-field characteristics of the coupled waveguide SLEDs exhibit a single-lobe far-field pattern when the gain and loss waveguides are biased at the injection current of 600 mA and 60 mA, respectively.
对反直觉增益/损耗耦合波导设计中的宇称-时间（PT）对称性破缺进行了数值和理论研究。从理论上确定了PT对称模式选择条件。制备并表征了单横向模式宽带砷化铟量子点（QD）超发光发光二极管（SLED）；PT对称广域SLED包含横向耦合的增益和损耗PT对称波导。通过宇称-时间对称性破缺实现单横向模式工作。宽带SLED呈现出均匀的类高斯发射光谱，3 dB带宽为110 nm。当增益和损耗波导分别在600 mA和60 mA的注入电流下偏置时，耦合波导SLED的远场特性呈现出单瓣远场图案。
