In this paper, we measure the emission energies of three different photonic band edge lasers containing nematic hosts which have slightly different physical properties. The low molar mass monomers used as nematic hosts are identical in terms of molecular shape except for the length of the terminal alkyl chain. The photonic band edge laser which contains an even number of methylene units in its alkyl chain is found to have the lowest lasing threshold at both the same absolute temperature and the same shifted temperature. At the same excitation energy the laser output for each sample is found to be proportional to the orientational order parameter of the nematic host. However, when plotted simultaneously the absolute value of the order parameter does not correlate with the same emission energies in each sample. As a result we consider other factors that maybe of equal importance to the operating efficiency of the PBE laser in order to obtain viable candidates that are able to explain the discrepancy in our results. Finally, we introduce a figure of merit parameter which contains the candidates most likely to affect the operating efficiency and obtain much better agreement with our results than with the orientational order parameter alone.

Date Published: 28 May 2004
PDF: 10 pages
Proc. SPIE 5289, Liquid Crystal Materials, Devices, and Applications X and Projection Displays X, (28 May 2004); doi: 10.1117/12.532180

Published in SPIE Proceedings Vol. 5289:
Liquid Crystal Materials, Devices, and Applications X and Projection Displays X
Ming Hsien Wu; Liang-Chy Chien, Editor(s)