Intersubband absorption with difference-frequency generation in GaAs asymmetric quantum wells

• 来源期刊: 中国物理B（英文版）
• 关键词: asymmetric quantum wells absorption coefficient THz-wave phase-matching
• 年，卷（期）: 2012,（8）
• 页码范围: 252-257
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1056/21/8/084207

摘要

An asymmetric quantum well (AQW) is designed to emit terahertz (THz) waves by using difference frequency generation (DFG) with the structure of GaAs/Al0.2Ga0.8As/Al0.5Ga0.5As.The characteristics of absorption coefficients are analysed under the parabolic and non-parabolic energy-band conditions in detail.We find that the absorption coefficients vary with the two pump optical intensities,and they reach the maxima when the pump wavelengths are given as λp1 =9.70 μm and λp2 =10.64 μm,respectively.Compared with non-parabolic conditions,the total absorption coefficient under parabolic conditions shows a blue shift,which is due to the increase in the energy difference between the ground and excited states.By adjusting the two pump optical intensities,the wave vector phase-matching condition inside the AQW is satisfied.