Tunable laser action in a dye-doped nematic liquid-crystal waveguide under holographic excitation based on electric-field-induced TM guided-mode modulation

Electrically tunable laser action has been demonstrated in a dye-doped nematic liquid-crystal (NLC) waveguide by holographic excitation. The optical feedback was provided by the distributed feedback induced by two-beam interference by use of the Lloyd mirror configuration. Electrical tuning of the lasing wavelength was realized owing to the change of the effective refractive index of the NLC core layer caused by the reorientation of NLC molecules. On the basis of a waveguiding mode theory, numerical analysis of a TM guided mode in the presence of an applied electric field was performed, and field-induced tuning of the lasing wavelength was investigated in detail. Prospects for the realization of a single-mode operation and tuning of the lasing wavelength were also shown. (C) 2004 Optical Society of America.