Low threshold random lasing in DDPDLCs, DDPDLC@ZnO nanoparticles and dye solution@ZnO nanoparticle capillaries

摘要

We study the random lasing in dye-doped polymer-dispersed liquid crystal (DDPDLC) capillaries in the presence of various materials. Random lasing from DDPDLC@liquid crystal droplets, DDPDLC@ZnO nanoparticles and dye solution@ZnO nanoparticles was observed under the excitation of a frequency-doubled Nd:YAG (yttrium aluminum garnet) laser operating at a wavelength of 532 nm. The variation of Eth with ε'_(sc,n)(ω) provides direct proof of the central role of local field enhancement in the emergence of threshold lasing resonance, and suggests the enlargement of gain by the local field enhancement. The behavior of the lasing spikes is also discussed for amplifying PDLC capillaries, providing additional insight into the lasing mechanism of these structures.