Chassagneux Y, Colombelli R, Maineults W, Barbieri S, Khanna S P, Linfield E H, Davies A G
Institut d'Electronique Fondamentale, Université Paris-Sud and CNRS, UMR8622, Orsay, France.
Opt Express. 2009 Jun 8;17(12):9491-502. doi: 10.1364/oe.17.009491.
We demonstrate a framework to understand and predict the far-field emission in terahertz frequency photonic-crystal quantum cascade lasers. The devices, which employ a high-performance three-well active region, are lithographically tunable and emit in the 104-120 microm wavelength range. A peak output power of 7 mW in pulsed mode is obtained at 10 K, and the typical device maximum operating temperature is 136 K. We identify the photonic-crystal band-edge states involved in the lasing process as originating from the hexapole and monopole modes at the G point of the photonic band structure, as designed. The theoretical far-field patterns, obtained via finite-difference time-domain simulations, are in excellent agreement with experiment. Polarization measurements further support the theory, and the role of the bonding wires in the emission process is elucidated.
我们展示了一个用于理解和预测太赫兹频率光子晶体量子级联激光器远场发射的框架。这些器件采用高性能三阱有源区，通过光刻可调节，发射波长范围在104 - 120微米。在10 K时，脉冲模式下获得了7 mW的峰值输出功率，典型器件的最高工作温度为136 K。我们确定了激光发射过程中涉及的光子晶体带边态，如设计的那样，源自光子带结构G点处的六极和单极模式。通过时域有限差分模拟获得的理论远场模式与实验结果高度吻合。偏振测量进一步支持了该理论，并阐明了键合线在发射过程中的作用。
