CUED Publications database

Liquid crystalline chromophores for photonic band-edge laser devices

Morris, SM and Qasim, MM and Gardiner, DJ and Hands, PJW and Castles, F and Tu, G and Huck, WTS and Friend, RH and Coles, HJ (2013) Liquid crystalline chromophores for photonic band-edge laser devices. Optical Materials, 35. pp. 837-842. ISSN 0925-3467

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Abstract

We present results on laser action from liquid crystal compounds whereby one sub-unit of the molecular structure consists of the cyano-substituted chromophore, {phenylene-bis (2-cyanopropene)}, similar to the basic unit of the semiconducting polymer structure poly(cyanoterephthalylidene). These compounds were found to exhibit nematic liquid crystal phases. In addition, by virtue of the liquid crystalline properties, the compounds were found to be highly miscible in wide temperature range commercial nematogen mixtures. When optically excited at λ = 355 nm, laser emission was observed in the blue/green region of the visible spectrum (480-530 nm) and at larger concentrations by weight than is achievable using conventional laser dyes. Upon increasing the concentration of dye from 2 to 5 wt.% the threshold was found to increase from Eth = 0.42 ± 0.02 μJ/pulse (≈20 mJ/cm2) to Eth = 0.66 ± 0.03 μJ/pulse (≈34 mJ/cm2). Laser emission was also observed at concentrations of 10 wt.% but was less stable than that observed for lower concentrations of the chromophore. © 2012 Elsevier B.V. All rights reserved.

Item Type: Article
Uncontrolled Keywords: Dyes Lasers Liquid crystals
Subjects: UNSPECIFIED
Divisions: Div B > Photonics
Div B > Solid State Electronics and Nanoscale Science
Depositing User: Cron Job
Date Deposited: 07 Mar 2014 11:29
Last Modified: 08 Dec 2014 02:21
DOI: 10.1016/j.optmat.2012.10.046