【摘要】 研究了一种新型的 ,基于金属 /半导体界面等离子体激元的波导结构 ,从理论上对激射波长在 17μm的GaAs AlGaAs量子级联激光器的波导层设计进行了讨论 ,分别研究了传统的递变低折射率波导设计和等离子体激元波导设计。结果表明 ,利用表面等离子体激元进行波导设计 ,可以降低波导层厚度和提高光场限制因子 ,从而为长波段 (如太赫兹频段 )激光器提供了一种有效的波导设计方法。更多还原

【Abstract】 Operation of a quantum cascade (QC) laser at long wavelengths (>15 μm) requires a good optical confinement of light in the waveguide, without resorting to the prohibitively thick waveguide layers. The new type of waveguide concept based on surface plasmons at the interface between metal and semiconductor was explored. Waveguides of GaAs/AlGaAs QC lasers operating at 17 μm are theoretically designed by the conventional low graded refractive index, a single-sided surface plasmon and a double-sided surface plasmon. A double-sided surface plasmon waveguide, showing the highest confinement of the optical mode intensity profile with the lowest thickness, is promising to be a viable waveguide solution to semiconductor laser in the terahertz (THz) range.更多还原