Spectroscopic behavior in whispering-gallery modes by edge formation of printed microdisk lasers

Abstract

Dynamic and rapid spectral shifts of whispering-gallery mode (WGM) from microdisk laser were studied. The microdisks with diameter about 100 μm were fabricated by ink-jet printing of Rhodamine 590 doped polymer. Sharper edge microdisk and rounder edge microdisk were pumped with Q-switched Nd:YAG laser(@532 nm). A spectral shift −3.77×10-3 nm/(μJ·mm-2) was occurred in the case of the rounder edge microdisk, which is smaller than the spectral shift −4.21×10-3 nm/(μJ·mm-2) in the case of the sharper edge microdisk. Expecting the anomalous dispersion and Rhodamine 590 degradation affect, under the same excitation condition, the WGM spatial modification can also led to the shifts. And the modification was caused by interaction between the sharpened-edge and the increased optical gain.