Triple and Double Photons Absorption Process and Down-Conversion Laser Emitting Investigation of Er-Ion Doped Microsphere

Abstract

We report a readily and cheap method to build taper optical fiber-Er 3+ doped microsphere platform to investigate upconversion fluorescence emission and down-conversion laser oscillation with low threshold pump power. We demonstrate to dope Er 3+ into silica microsphere surface by dipping a single-taper optical fiber into a certain concentration of erbium nitrate solution (Er(NO 3 )) , then dry it and use the electrical-arc of the optical fiber splicer to melt the tip of taper fiber to form the Er 3+ -doped silica microsphere due to surface tension induced. We also present a HF acid etching setup to fabricate low loss biconical optical taper fibers. We demonstrate the Er 3+ doped silica mic r osphere triple photons and dual photons absorption process of up-conversion fluorescence emission and down-conversion laser oscillation spectra by using the optical tapered fiber to couple 976 nm/1534 nm pump light source.