Variable optical buffer using slow light in semiconductor nanostructures

We proposed a compact variable all-optical buffer using slow-light in semiconductor nanostructures. We discuss the general design principle via dispersion engineering. The buffering effect is achieved by slowing down the optical signal using an external control light source to vary the dispersion characteristic of the medium via electromagnetically induced transparency effect. We demonstrate that the semiconductor quantum dot structures can be used as a slow-light medium. In such structure, the total buffering time is variable and controlled by an external pump laser. We present a theoretical investigation of the criteria for achieving slow light in semiconductor quantum dots. New pump scheme is proposed to overcome the sample nonuniformity. Finally, optical signal propagation through the semiconductor optical buffer is presented to demonstrate the feasibility for practical applications.