Despite numerous efforts, continuous wave (CW) lasing in dye doped, one-dimensional (1D) photonic bandgap cholesteric liquid crystal (CLC) structures has not been previously reported, to our knowledge. Here we report on the observation of lasing in such structures under both coherent (laser) and incoherent (LED) CW light excitation. To achieve this effect, we used a 1D-photonic bandgap structure made of a polymer stabilized CLC with a pitch gradient across the cell thickness. A spectral reflectivity profile of such a CLC structure reveals local minima in the area within a photonic stopband and close to it. The realization of lasing pumped by low power CW light sources opens the possibility of all-organic, compact, tunable CW lasers for display and medical applications.
© 2012 Optical Society of America
Original Manuscript: November 21, 2011
Revised Manuscript: March 6, 2012
Manuscript Accepted: June 14, 2012
Published: July 12, 2012
Vol. 7, Iss. 9 Virtual Journal for Biomedical Optics
A. Muñoz, M. E. McConney, T. Kosa, P. Luchette, L. Sukhomlinova, T. J. White, T. J. Bunning, and B. Taheri, "Continuous wave mirrorless lasing in cholesteric liquid crystals with a pitch gradient across the cell gap," Opt. Lett. 37, 2904-2906 (2012)