Nanoparticle-coated optical microresonators for whispering-gallery lasing and other applications

Abstract

Scope and Method of Study:

The purpose of this study is to explore the properties of high quality optical microsphere resonators in combination with various types of nanoparticles deposited on their surfaces. Optical whispering-gallery modes of the silica microspheres were pumped efficiently by tapered optical fibers. For whispering-gallery lasing, the microspheres were coated with HgTe and HgCdTe quantum dots. Gold nanorods were grown on the surface of the microspheres nucleated by HgTe nanoparticles.

Findings and Conclusions:

Lasing in HgTe was demonstrated for the first time and record low thresholds were measured in these devices. Interesting effect on enhancement of evanescent coupling was observed with microsphere resonators with gold nanorods grown on their surfaces. We develop a new procedure that uses semiconductor nanoparticles as seeds for growth of gold nanorods.