Survey of switchable lasing configurations using structures of liquid crystal and polymer dispersions

Abstract

We investigate the fabrication of holographic polymer dispersed liquid crystals (H-PDLCs) for use as switchable laser cavities. H-PDLCs are liquid crystal and polymer dispersions used in grating applications for displays, optical communications and optical security. By controlling the pitch of the H-PDLC and the laser dye used, we are able to fabricate a tunable laser. H-PDLCs were made in both reflection and transmission modes to vary the method by which lasing action occurs. The dye-doped H-PDLCs were pumped with nanosecond pulses from a laser with emission at 532 nm and a power of approximately 6 mJ. Lasing action was observed using a spectrometer from the H-PDLC grating; peak wavelengths occurred over a range of wavelengths, depending on the dye used, with the full width of the emission peaks approximately 6-8 nm at half maximum. The lasing action can be turned on and off by the application and removal of an electric field due to the properties of an H-PDLC. Furthermore, we investigate multidimensional architectures and quasicrystal symmetries for lasing applications. Applications for these cells include use in small-scale portable devices requiring a tunable laser source.