Refractory material with surface plasmonic structures have the function of spectrum selective absorption and radiation spectrum regulation. In this paper, we design an absorber with periodic cylindrical nanostructures and a dielectric layer of Al<sub>2</sub>O<sub>3</sub> based on the substrate of metal Tantalum (Ta). The energy absorption characteristics of the absorber have been simulated and analyzed by changing various constructional parameters. The simulation results indicate that structural parameters have great influence on the spectrum absorption in the range of wavelength 400-4000nm. The period and radius of nanostructure have a important effect on the absorption peaks in the infrared region. Infrared absorption peak can reach more than 99% and produce a red shift due to parameters changing. At the whole visible field, the absorption enhancement effect is significant. The refractive index and thickness of dielectric layer also have an obviously effect on the absorption spectrum. Furthermore, it is also obviously that thickness of dielectric layer has enhancement effect on absorption of infrared spectrum. The research found that the absorption and radiation spectrum of surface plasmonic materials can be effectively controlled by combining the high temperature radiation characteristics of high temperature metal. Thermophotovoltaic system can provide a kind of new methods and ideas for improving conversion efficiency, energy saving and consumption reducing.
An optical system model has been built up for evaluating de-coherence performance of Mie scattering by using ZEMAX software. The optical system consists of a linearly polarized laser source of the wavelength 0.6328 micrometer, the interferometer configuration with a double-arm beam path, the light pipe with the particles solution of variable parameters including the refractive index, the particle size and the particle concentration, and the detectors. Seven types of particles with different refractive index have been used as scattering medium. The de-coherence performance and the light energy loss have been calculated for solutions with different particle concentration and dimension. The calculated results indicate that the de-coherence performance can be improved by increasing the particle concentration in solution and the particle size. The improvement of the performance is more notable as the particle refractive index becomes higher. The dependence of the light energy loss caused by Mie scattering on the refractive index and size of the particle, and the particle concentration in solution is obtained.
In this work, a multilayered dielectric film and metallic film are used as reflecting surface to fabricate light
pipe. Linearly polarized laser beam with wave length of 532nm enters into the light pipe. After
multi-reflection process, laser beam come out from the light pipe. We have found that the polarization state of
linearly polarized incident light after reflection are different for the light pipe coated with metal and
multilayered dielectric film. We also found a distributed polarization characteristic in the output optical field.
The polarization degree has been simulated by using ZEMAX software. Laser speckle contrast from a glass
diffuser is measured to exam the simulated result.
In this paper, the theoretical analysis and numerical simulation with regard to the temperature characteristics of LiNbO<sub>3</sub>
crystal electro-optic modulator are putted in practice by applying linear electro-optic effect coupling wave theory. The
temperature stable conditions of LiNbO<sub>3</sub> crystal electro-optic modulator are theoretically illustrated through optimizing
some sensitive factors such as crystal length, lightwave incident direction, and so on. As a result, it can be used as a
useful theoretical guidance for the design and practical utilization of LiNbO<sub>3</sub> crystal electro-optic modulator.
At present, bidirectional transmission over a signal fiber is applied in many fields, such as WDM. Bidirectional
transmission over a signal fiber can reduce the required number of fibers and uses one optical source, so it is lower cost
than unidirectional transmission counterparts. In this paper, the phase-noise counteracting characteristic in the
bidirectional transmission over a polarization maintaining fiber (PMF) due to different polarization rotating angle of
counter-propagation light is analyzed. The analyzing results indicate that the bidirectional system with a special
polarization rotating angle of counter- propagation light has a good property that can counteract phase noises coming
from external factors such as temperature etc. reciprocal factors. Thus, phases' fluctuation can be reduced and it has the
advantages of measuring phase change and achieving phase calibration. Based on the result, using Jones matrix, the
established system is discussed and the phase difference owing to nonreciprocal parameters such as Faraday
electromagnetic induction is obtained. So the calibration of phase is achieved according to the measured results.