Fabrication and characterization of a hybrid surface-plasmonic cavity
Han Yeh1*, Chien-Ju Lee1, Yen-Chun Chen1, Chun-Yuan Wang2, Shangir 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
33Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan
* presenting author:葉涵, email:maggieyeh15@yahoo.com.tw
Surface plasmons are electron density waves confined at metal surfaces or interfaces between metals and dielectrics. In our experiment, GaAs microdisks and microrings with embedded InAs quantum dots as a gain medium are fabricated and transferred onto single crystalline gold flakes capped with a Al2O3 layer. A viscoelastic stamp is used to transfer the GaAs microdisks with a high positioning precision. Photoluminescence measurements indicate that such a hybrid structure forms a plasmonic cavity in the nanometers-thick dielectric layer, which supports plasmonic whispering-gallery modes with Q factors up to 100. The observed plasmonic modes have been further identified by finite-element simulations. The transfer method developed here combined with large area gold flakes provides a simple mean to fabricate and integrate plasmonic cavities without the need of sophisticated nano-fabrication processes.

Keywords: microcavities, microdisks, surface plasmons