Circularly Polarized Lasers from Solid Films Comprising Chiral Conjugated Oligomers Doped with Functionalized Oligofluorenes

摘要

Since the first successful demonstration of circularly polarized lasers using cholesteric liquid crystal films three decades ago, intensive efforts have been made to overcome hurdles to potential applications as medical diagnostics, quantum cryptography, optical interconnects, optical switches and modulators. The orientational order parameter governing the laser dye's emission dipole is critical to spectral purity. The most commonly used laser dye, DCM (4-(dicyanomethylene)-2-methyl-6-(4-dimethyl-aminostryl)-4H-pyran), is capable of a very modest orientational order parameter less than 0.40. In addition to ensuring spectral purity, a high orientation order parameter is expected to increase lasing efficiency and to decrease threshold.