Electrically switchable lasing from pyrromethene 597 embedded holographic-polymer dispersed liquid crystals

Abstract

One-dimensional photonic band gap (PBG) materials created from holographic polymer dispersed liquid crystals (H-PDLCs) provide enhanced light localization in an organic electro-optic device. Distributed feedback within the reflection notch of a H-PDLC grating narrowed the bandwidth of pyrromethene 597 fluorescence from 56 to 8.4nm at a lasing threshold of 0.12mJcm−2, compared to 2.6mJcm−2 required to observe amplified spontaneous emission in a nonstructured, but comparable floodlit (PDLC) sample. Application of an electric field (10–40V∕μm) continuously decreased the diffraction efficiency of the grating and the commensurate dynamic lasing intensity thus demonstrating electrically modulated gain from an optically pumped, all-organic PBG.