Liquid crystalline chromophores for photonic band-edge laser devices Damian Gardiner IntroductionResearch on band-edge laser devices based upon liquid crystals (LCs) has garnered interest in recent years due to the remarkable combination of characteristics that are achievable with this type of organic laser .
In this paper we investigate Photonic Band Edge (PBE) lasing from a homologous series of non-symmetric bimesogen liquid crystals (the mesogenic units are not identical) with varying physical Lasing in a three-dimensional photonic crystal of the Photonic-bandgap materials, with periodicity in one, two or three dimensions, offer control of spontaneous emission and photon localization. Low-threshold lasing has been demonstrated in two-dimensional photonic-bandgap materials, both with distributed feedback and defect modes. Liquid crystals
Apr 12, 2005 · 12 April 2005 Lasing in photonic crystals based on dye-doped liquid crystal films (Invited Paper) Tsung-Hsien Lin , Yi-Jan Chen , Chun-Hui Wu , J.-H. Liu , Liquid Crystal Lasers Request PDFLasing that is color-tunable via application of an electric field has been demonstrated at the edge of the 1D photonic band of a dye-doped chiral smectic liquid crystal with a periodic spiral
Jun 13, 2002 · This inherent distributed cavity effect modifies the fluorescence spectrum, and, if the material is optically pumped, allows population inversion and mirrorless lasing. We have studied emission from thin samples of liquid crystalline materials optically pumped by pico- and nanosecond laser pulses. Multi-wavelength laser tuning based on cholesteric By doping a fluorescent dye into the CLC (dye-doped CLC, dye-doped cholesteric liquid crystal (DDCLC)), a mirrorless laser action can be easily gen- erated if
This study shows the results of a photonic band-edge laser using dye-doped cholesteric liquid crystals (CLCs) combined with silver (Ag) nanoparticles. When the Ag nanoparticle surface plasmon resonance wavelength matched the excitation source wavelength, the large optical fields provided by surface plasmons increased the fluorescence of dye molecules by enhancing the molecular excitation rate Optical Properties of Laser Lines and Fluorescent Spectrum It is particularly interesting to see that the fluorescence intensity and shape could be controlled by adjusting the external geometrical factor of the photonic band gaps. The lasing threshold of the CLC lasers was in the range of 1.5-5.3 J/pulse.
Wenyi Cao, Fluorescence and lasing in liquid crystalline photonic bandgap materials, (2005) Jeremy Neal, Orientationally ordered particles:characterization and applications, (2010) Jacob Fontana, Self-assembly and characterization of anisotropic metamaterials, (2010) Photonic Band Gap Aspects of Liquid Crystals Institute Liquid crystals with modulated ground states are periodic dielectric structures, and hence they are self-assembled photonic band gap materials. Fluorescent emission is suppressed in the stop band, but is enhanced at the band edges, and, above a pump threshold, distributed feedback lasing occurs. We interpret experimental observations of reflectance, fluorescence and lasing in terms of the density of states, and give a detailed description of this for helical cholesteric liquid crystals.
DCM dye and (c) the narrow band laser output of a typical liquid crystal laser. In addition to PBE lasing, defect-mode lasing has also been demonstrated whereby an artefact is incorporated into the system so as to disturb the periodicity. This then results in a resonant lasing mode at the centre of the photonic Replica Symmetry Breaking in Cholesteric Liquid Crystal Replica Symmetry Breaking in Cholesteric Liquid Crystal Bandgap Lasing Jinyuan Kong Laboratory of Optical Fibers and MicroNano Photonics, School of Instrument Science and OptoElectronics Engineering, Hefei University of Technology, Hefei, Anhui, 230009 P. R. China
been observed from dye-doped cholesteric liquid crystals (DDCLCs) [910, ]. The switch between photonic band-edge and random lasing has attracted some attention . In 11, this paper, the switch between photonic band-edge and ran dom lasing was achieved by controlling the relative position of the 1D photonic band gap and the fluorescence emission Thermally switchable photonic band-edge to random laser By changing the doping concentration of the chiral agent to adjust the relative position of the reflection band of cholesteric liquid crystals and the fluorescence emission spectrum of the dye, photonic band-edge and random lasing were observed, respectively. The reflection band of the cholesteric phase liquid crystal can also be controlled by adjusting the temperature:the reflection band is
Wide-angle lasing emitting from dye-doped blue-phase liquid crystals (DDBPLCs), which are analogous to photonic crystals, have been demonstrated to selectively reflect visible light. Herein, the best mixed system ZTO-5024LA+S811 was chosen as it required minimal applied voltage for wavelength tuning and exhi PhotonicsFluorescence and lasing in liquid crystalline photonic Cholesteric liquid crystals (CLCs) and cholesteric blue phases (BPs) are one-dimensional and three-dimensional photonic bandgap (PGB) materials. In this work, fluorescence and lasing are experimentally studied in dye-doped CLC films and BPs, together with the calculations of density of states rho in CLC films.