To meet the application need for agile precision beam steering, a novel liquid crystal prism device with a simple structure, convenient control, low cost and applicable performance is presented, and analysed theoretic...To meet the application need for agile precision beam steering, a novel liquid crystal prism device with a simple structure, convenient control, low cost and applicable performance is presented, and analysed theoretically and experimentally. The relationships between the optical path and the thickness of the liquid crystal cell under different voltages are investigated quantitatively by using a theoretical model. Analysis results show that the optical path profile of the liquid crystal prism has a quasi-linear slope and the standard deviation of the linear slope is less than 16 nm. The slope ratio can be changed by a voltage, which achieves the programmable beam steering and control. Practical liquid crystal prism devices are fabricated. Their deflection angles and wavefront profiles with different voltages are experimentally tested. The results are in good agreement with the simulated results. The results imply that the agile beam steering in a scope of 100μrad with a micro-rad resolution is substantiated in the device. The two-dimensional beam steering is also achieved by cascading two liquid crystal prism devices.展开更多
The vectorial eigenvector method was applied to compute the cylindrical vector(CV) modes of polarization-dependent resonators and multiple modes in the CV mode selected resonator were tracked. Then, the mode character...The vectorial eigenvector method was applied to compute the cylindrical vector(CV) modes of polarization-dependent resonators and multiple modes in the CV mode selected resonator were tracked. Then, the mode characteristics of CV mode selected resonator depending on the Fresnel number, geometry parameters, and polarization parameters were simulated.When the difference in reflection coefficient between radial and azimuthal polarization is greater than 0.021 for spherical semi-confocal cavity, the radially polarized TM01*mode most probably appears in the resonator due to its lowest loss,which is consistent with an azimuthal polarization-selective resonant cavity. Moreover, the appropriate phase shift factor contributes to suppress non-rotationally symmetrical modes, which promotes the selection of CV modes. The Fresnel number between 2 and 2.5 are the appropriate range of values when the value of geometry parameters g2 is 0.5, both of which decide the effective Fresnel number.展开更多
Dichroic behaviors of layered ReS2 have been characterized using angular dependent polarizedabsorption and resistivity measurements in the van der Waal plane. The angular dependent optical and electrical measurements ...Dichroic behaviors of layered ReS2 have been characterized using angular dependent polarizedabsorption and resistivity measurements in the van der Waal plane. The angular dependent optical and electrical measurements are carried out with angles ranging from θ= 0°(E || b) to θ= 90°(E ^b) with respect to the layer crystal’s b-axis. The angular de pendence of polarized energy gaps of ReS2 shows a sinusoidal variation of energies from ~1.341 eV (E ||b to ~1.391 eV (E ^ b). The experimental evidence of polarized energy gap leaves ReS2 apotential usage for fabrication of a polarized optical switch suitable for polarized optical communication in nearinfrared (NIR) region. Angular dependence of resistivities of ReS2 in?the vander Waal plane has also been evaluated. The relationship of inplane resistivities shows a sinusoidallike variation from θ= 0°(E ||b) to 90°(E ^ b) and repeated periodically to 360°. The experimental results of optical and electrical measurements indicated that ReS2 is not only an opticaldichroic layer but also an electricaldichroism material presented in the layer plane.展开更多
基金supported by the National High Technology Research and Development Program of China(Grant No.2009AA8042017)the Postdoctoral Science Foundation of University of Electronic Science and Technology of China
文摘To meet the application need for agile precision beam steering, a novel liquid crystal prism device with a simple structure, convenient control, low cost and applicable performance is presented, and analysed theoretically and experimentally. The relationships between the optical path and the thickness of the liquid crystal cell under different voltages are investigated quantitatively by using a theoretical model. Analysis results show that the optical path profile of the liquid crystal prism has a quasi-linear slope and the standard deviation of the linear slope is less than 16 nm. The slope ratio can be changed by a voltage, which achieves the programmable beam steering and control. Practical liquid crystal prism devices are fabricated. Their deflection angles and wavefront profiles with different voltages are experimentally tested. The results are in good agreement with the simulated results. The results imply that the agile beam steering in a scope of 100μrad with a micro-rad resolution is substantiated in the device. The two-dimensional beam steering is also achieved by cascading two liquid crystal prism devices.
基金Project supported by the National Natural Science Foundation of China(Grant No.61308045)the National Science and Technology Cooperation Project(Grant No.2014DFR10870)
文摘The vectorial eigenvector method was applied to compute the cylindrical vector(CV) modes of polarization-dependent resonators and multiple modes in the CV mode selected resonator were tracked. Then, the mode characteristics of CV mode selected resonator depending on the Fresnel number, geometry parameters, and polarization parameters were simulated.When the difference in reflection coefficient between radial and azimuthal polarization is greater than 0.021 for spherical semi-confocal cavity, the radially polarized TM01*mode most probably appears in the resonator due to its lowest loss,which is consistent with an azimuthal polarization-selective resonant cavity. Moreover, the appropriate phase shift factor contributes to suppress non-rotationally symmetrical modes, which promotes the selection of CV modes. The Fresnel number between 2 and 2.5 are the appropriate range of values when the value of geometry parameters g2 is 0.5, both of which decide the effective Fresnel number.
文摘Dichroic behaviors of layered ReS2 have been characterized using angular dependent polarizedabsorption and resistivity measurements in the van der Waal plane. The angular dependent optical and electrical measurements are carried out with angles ranging from θ= 0°(E || b) to θ= 90°(E ^b) with respect to the layer crystal’s b-axis. The angular de pendence of polarized energy gaps of ReS2 shows a sinusoidal variation of energies from ~1.341 eV (E ||b to ~1.391 eV (E ^ b). The experimental evidence of polarized energy gap leaves ReS2 apotential usage for fabrication of a polarized optical switch suitable for polarized optical communication in nearinfrared (NIR) region. Angular dependence of resistivities of ReS2 in?the vander Waal plane has also been evaluated. The relationship of inplane resistivities shows a sinusoidallike variation from θ= 0°(E ||b) to 90°(E ^ b) and repeated periodically to 360°. The experimental results of optical and electrical measurements indicated that ReS2 is not only an opticaldichroic layer but also an electricaldichroism material presented in the layer plane.
