High efficiency four-wave mixing in double asymmetry quantum dots

Spyridon G. Kosionis

Xiangying Hao, Jiahua Li, Ji-Bing Liu +2 more

Chunling Ding, Xiangying Hao, Jiahua Li +1 more

Xiangying Hao, Jing Wu, Ying Wang

With the presence of the signal pulse, a quantum dot (QD) four-level structure interacting with four fields forms a double-cascade configuration. The linear optical properties for amplification, absorption, and dispersion of two weak near-infrared (NIR) lights in this scheme are investigated. It shows that the amplification, transparency, normal and anomalous dispersion of the probe and signal fields, i.e., the two NIR waves, can be achieved by adjusting the relative phase of the applied lasers, the probe detuning, and the two pump Rabi energies appropriately, while when the signal pulse is removed, the nonlinear optical phenomenon four-wave mixing (FWM) originating from quantum interference is demonstrated. A highly efficient FWM process with a NIR mixing field generated can be realized in this system. Such investigation in a semiconductor QD system with flexible design and widely adjustable parameters may provide new possibilities for realizing the efficient generation and gain of NIR waves and manipulating light propagation between subluminal and superluminal in the solid-state materials.

Wen-Long Xiong, Xiao-Qiu Qi, Aixi Chen

Yueping Niu, Ruxin Li, Shangqing Gong

A five-level tripod scheme is proposed for obtaining a high efficiency four-wave-mixing (FWM) process. The existence of double-dark resonances leads to a strong modification of the absorption and dispersion properties against a pump wave at two transparency windows. We show that both of them can be used to open the four-wave mixing channel and produce efficient mixing waves. In particular, higher FWM efficiency is always produced at the transparent window corresponding to the relatively weak-coupling field. By manipulating the intensity of the two coupling fields, the conversion efficiency of FWM can be controlled.