All-optical tuning of a quantum dot in a coupled cavity system

We demonstrate a method for tuning a semiconductor quantum dot (QD) onto resonance with a cavity mode all-optically using a system comprised of two evanescently coupled cavities containing a single QD. One resonance of the coupled cavity system is utilized to generate a cavity enhanced optical Stark shift, enabling the QD to be resonantly tuned to the other cavity mode. A twenty-seven fold increase in photon emission from the QD is measured when the off-resonant QD is Stark shifted onto the cavity mode resonance, which is attributed to radiative enhancement of the QD. A maximum tuning of 0.06 nm is achieved for the QD at an incident power of 88 mu W. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4719065]