Multi-wavelength laser from dye-doped cholesteric polymer films

A multi-wavelength laser is demonstrated using a dye-doped cholesteric polymer film whose reflection bandwidth is broadened with several oscillations. Due to the abrupt change of the density of state between oscillation peak and valley, each oscillation functions as a photonic band gap for generating a laser wavelength under the excitation of a pumping laser. As a result, a multiple wavelength laser is generated. Results indicate that the dye-doped cholesteric liquid crystal polymer film is a good candidate for fabricating broadband lasers such as white light lasers. Potential applications include experimental testing of laser materials, identification markers, information displays, and inertial confinement laser fusion

Simulations of liquid-crystal Fabry-Perot etalons by an improved 4X4 matrix method

The optical performances of a liquid crystal (LC) Fabry-Perot (FP) etalon in various configurations were simulated by a faster 4 x 4 matrix method. Results show that the FP with a 90degrees twisted nematic LC is polarization. insensitive if the applied voltage exceeds similar to3X of the Freedericksz transition threshold. This method can well depict the transmission spectra of the FP cavity and, therefore, is useful for optimizing the FP tunable filters for telecommunications