Showing papers by "Chenming Hu published in 1974"
TL;DR: In this article, the absorption and scattering losses at 6328 A in MBBA thin-film waveguides were measured with a thermal-lens technique and were found to be highly dichroic.
Abstract: The absorption and scattering losses at 6328 A in MBBA thin-film waveguides were measured. The absorption loss was studied with a thermal-lens technique and was found to be highly dichroic. Thermal self-focusing was observed for the ordinary ray. The measured scattering losses were between 15 and 40 dB cm−1, depending on the polarization and the liquid-crystal orientation. A modified bulk-scattering loss caused by the thermal fluctuation of the long-range-crystal ordering is calculated and compared with the measurements.
60 citations
TL;DR: In this paper, the phase velocities of the optical waves guided in nematic-liquid-crystal waveguides can be electrically modulated by about 10 percent, and the response time of the effect is in the millisecond range.
Abstract: The phase velocities of the optical waves guided in nematic-liquid-crystal waveguides can be electrically modulated by about 10 percent. Optical deflection in such waveguides are demonstrated in a configuration with an electric field applied across a film of thickness of the order of 1 μ. Effective index of refraction is changed by about 0.01/volt. Response time of the effect is in the millisecond range. Results of an analysis show good agreement with the measurements.
25 citations
TL;DR: In this article, the phase-velocity tuning of thin-film liquid-crystal waveguides was analyzed by a numerical method, and a three-layer model of the waveguide was provided, which is in good agreement with the measured data.
Abstract: An external electric field exerts volume torque on the nematic liquid crystal due to the anisotropic molecular polarizability and tends to reorient the molecular axes. Phase-velocity tuning in these materials is thus possible. Eigenmodes of thin-film liquid-crystal waveguides are analyzed by a numerical method. A three-layer model of the waveguides is found to be in good agreement with the measured data, thus providing a simplified model for conceptual thinking as well as for computation.
13 citations