Spatially tunable laser emission in dye-doped cholesteric polymer films

Abstract

Position sensitive, continuous wavelength tunable laser based on photopolymerizable cholesteric liquid crystals with an in-plane helix alignment Applied Physics Letters 94, 093306 (2009);

Polarization-tunable chiral nematic liquid crystal lasing

“…Accordingly, extensive work has been performed on the lasing action of CLCs. [4][5][6][7][8] Many works have studied the control of the lasing action in the dye-doped CLC system using external stimuli, such as heat, 9,10 electrical field, 11,12 optical field, 13,14 and mechanical stress. 15 The chiral structure of dye-doped CLCs causes laser emission that is generated to be typically circularly polarized in the same sense as the cholesteric helix.…”

Optically pumped mirrorless lasing. A Review. Part II. Lasing in photonic crystals and microcavities

“…Temperature tuning can be direct (due to a temperature dependence of the pitch as a consequence of temperature-dependent elastic LC properties) or indirect (e.g., through a temperature-dependent solubility of the chiral agent [86]). The approach of oversaturated chiral agents provides multi-wavelength lasing [88].…”

“…Spatial tuning of the lasing may be implemented if a gradient of the pitch is formed in a dye-doped ChLC sample, moving the spot of the pumping light along the pitch gradient direction. The pitch gradient can be produced via placing in contact two ChLC mixtures with different concentrations of the chiral agent [83], by photo-patterning [85], or through a temperature dependence of solubility of the chiral agent [86]. A position-sensitive dye-doped ChLC laser covering a whole visible range has been fabricated by the authors of Ref.…”

Self-assembled organic and polymer photonic crystals for laser applications

“…Recently, the CG-PBG structures of photopolymerized CLCs have been prepared for the positiondependent tuning of laser emission. 77,78 However, the CG-PBG structures require high threshold excitation energies for laser action after photopolymerization. This is because the initial planar CLC alignment or fluorescent dyes might be deteriorated during photopolymerization of CLC monomers.…”

“…This is because the initial planar CLC alignment or fluorescent dyes might be deteriorated during photopolymerization of CLC monomers. [77][78][79] This section presents the preparation of a fluorescent glass-forming CLC (G-CLC) and its application in a new type of tunable CLC solidstate laser. 80 We succeeded herein in the relatively easy fabrication of robust CG-PBG structures of a fluorescent G-CLC without any covalent bonding by a supercooling process.…”