Efficient single photon source based on an InAs quantum dot embedded in a hybrid waveguide structure
Chien-Ju Lee1*, Han Yeh1, Yen-Chun Chen1, Shan-Gir Gwo2, Jer-Shing Huang3, Wen-Hao Chang1
1Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan
2Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
3Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan
* presenting author:Chien-Ju Lee, email:Chienju1016@gmail.com
Efficient solid-state single photon sources play an important role in optical quantum information science. However, the high reflective index of solid state materials has always been an obstacle for efficient single photon extraction. We demonstrate a simple method based on a plasmon assisted photonic waveguide structure that allows single photon extraction efficiency to reach 40 percent. The single photon device consists of an InAs quantum dot (QD) embedded in a GaAs waveguide which lies on top of a single crystalline gold flake with a 5 nanometer dielectric gap in between. This structure requires only standard semiconductor fabrication techniques and is relatively easy to fabricate. The emission lines show high degree of polarization preferences and can be an evidence of the coupling effect of the QD emission and the waveguide modes. Furthermore, through temperature dependent photoluminescence measurement, it is shown that the single photon extraction efficiency remains high until 60 Kelvin. This non-resonant coupling approach of the emitter and the photonic structure provides a broadband platform for efficient single photon extraction.

Keywords: single photon source, quamtum dots, microcavities