CUED Publications database

Red-Green-Blue 2D tuneable liquid crystal laser devices

Coles, HJ and Morris, SM and Ford, AD and Hands, PJW and Wilkinson, TD (2009) Red-Green-Blue 2D tuneable liquid crystal laser devices. Proc SPIE Int Soc Opt Eng, 7414. ISSN 0277-786X

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Abstract

In this paper, we review our recent experimental work on coherent and blue phase liquid crystal lasers.We will present results on thin-film photonic band edge lasing devices using dye-doped low molar mass liquid crystals in self-organised chiral nematic and blue phases. We show that high Q-factor lasers can be achieved in these materials and demonstrate that a single mode output with a very narrow line width can be readily achievable in well-aligned mono-domain samples. Further, we have found that the performance of the laser, i.e. the slope efficiency and the excitation threshold, are dependent upon the physical parameters of the low molar mass chiral nematic liquid crystals. Specifically, slope efficiencies greater than 60% could be achieved depending upon the materials used and the device geometry employed. We will discuss the important parameters of the liquid crystal host/dye guest materials and device configuration that are needed to achieve such high slope efficiencies. Further we demonstrate how the wavelength of the laser can be tuned using an in-plane electric field in a direction perpendicular to the helix axis via a flexoelectric mechanism as well as thermally using thermochromic effects. We will then briefly outline data on room temperature blue phase lasers and further show how liquid crystal/lenslet arrays have been used to demonstrate 2D laser emission of any desired wavelength. Finally, we present preliminary data on LED/incoherent pumping of RG liquid crystal lasers leading to a continuous wave output. © 2009 SPIE.

Item Type: Article
Uncontrolled Keywords: Blue phase Blue phasis Chiral nematic liquid crystals Chiral nematics Continuous Wave Device configurations Device geometries Dye-doped Excitation threshold Flexoelectric Helix axis High Q factor High slope efficiency In-plane electric fields Laser emission Liquid-crystal lasers Molar mass liquid crystals Monodomains Narrow-line width Photonic band edge Physical parameters Preliminary data Red green blues Room temperature Self-organised Single mode Slope efficiencies Thermochromic effects Well-aligned Continuous wave lasers Electric fields Laser excitation Liquid crystals Liquid lasers Liquids Photonic crystals Pumping (laser) Nematic liquid crystals
Subjects: UNSPECIFIED
Divisions: Div B > Photonics
Depositing User: Cron Job
Date Deposited: 07 Mar 2014 11:51
Last Modified: 19 May 2014 01:11
DOI: 10.1117/12.831230