Significant reduction of the bulk resistivity in a ferroelectric Pb(Zr_(0.45)Ti_(0.55))O_(3)thin film is observed before the remnant polarization started to decrease noticeably at the onset of its fatigue switching pr...Significant reduction of the bulk resistivity in a ferroelectric Pb(Zr_(0.45)Ti_(0.55))O_(3)thin film is observed before the remnant polarization started to decrease noticeably at the onset of its fatigue switching process.It is associated with the increase of charge carriers within the central bulk region of the film.The decrease of bulk resistivity would result in the increase of Joule heating effect,improving the temperature of the thin film,which is evaluated by the heat conduction analysis.The Joule heating effect in turn accelerates the polarization reduction,i.e.fatigue.Enhancing the heat dissipation of a ferroelectric capacitor is shown to be able to improve the device's fatigue endurance effectively.展开更多
This Letter describes an approach to encode complex-amplitude light waves with spatiotemporal double-phase holograms(DPHs) for overcoming the limit of the space-bandwidth product(SBP) delivered by existing methods. To...This Letter describes an approach to encode complex-amplitude light waves with spatiotemporal double-phase holograms(DPHs) for overcoming the limit of the space-bandwidth product(SBP) delivered by existing methods. To construct DPHs, two spatially macro-pixel encoded phase components are employed in the SBP-preserved resampling of complex holograms. Four generated sub-DPHs are displayed sequentially in time for high-quality holographic image reconstruction without reducing the image size or discarding any image terms when the DPHs are interweaved. The reconstructed holographic images contain more details and less speckle noise, with their signal-to-noise ratio and structure similarity index being improved by 14.64% and 78.79%,respectively.展开更多
Wavelength-dependent birefringence and dielectric anisotropy.two major optical properties of the nematie liquid crystal materials used in phase-only liquid crystal on silicon（LCOS） devices,are measured as a function...Wavelength-dependent birefringence and dielectric anisotropy.two major optical properties of the nematie liquid crystal materials used in phase-only liquid crystal on silicon（LCOS） devices,are measured as a function of operating temperatures.The dynamic phase modulation depth and threshold voltage of these phase-only LCOS devices are also measured in the corresponding temperature range and compared with theoretical predictions.The results show that the dynamic response time can he reduced significantly by an appropriate increase ol device operative temperature,while the necessary device elements,such as phase modulation depth and threshold voltage,can be maintained at the same time.展开更多
A simple and effective approach is proposed to minimize the effect of unmodulated light and uneven intensity caused by the pixelated structure of the spatial light modulator in a holographic display. A more uniform im...A simple and effective approach is proposed to minimize the effect of unmodulated light and uneven intensity caused by the pixelated structure of the spatial light modulator in a holographic display. A more uniform image is produced by purposely shifting the holographic images of multiple reconstructed lights with different incident angles from the zero-diffraction-order and overlapping those selected different orders. The simulation and optical experimental results show that the influence of the zero-diffraction-order can be reduced, while keeping the good uniformity of the target images by this new approach.展开更多
基金Supported in part by the EPSRC under Grant No GR/S98412/01the Beijing Natural Science Foundation of China under Grant No 4122005+1 种基金the Natural Science Foundation of China under Grant No 61201046the Research Fund for the Doctoral Program of Higher Education of China under Grant No 20121103120019.
文摘Significant reduction of the bulk resistivity in a ferroelectric Pb(Zr_(0.45)Ti_(0.55))O_(3)thin film is observed before the remnant polarization started to decrease noticeably at the onset of its fatigue switching process.It is associated with the increase of charge carriers within the central bulk region of the film.The decrease of bulk resistivity would result in the increase of Joule heating effect,improving the temperature of the thin film,which is evaluated by the heat conduction analysis.The Joule heating effect in turn accelerates the polarization reduction,i.e.fatigue.Enhancing the heat dissipation of a ferroelectric capacitor is shown to be able to improve the device's fatigue endurance effectively.
基金supported by the National Natural Science Foundation of China (NSFC)(Nos. 61827825 and 61775117)Tsinghua University Initiative Scientific Research Program (No. 20193080075)the Cambridge Tsinghua Joint Research Initiative
文摘This Letter describes an approach to encode complex-amplitude light waves with spatiotemporal double-phase holograms(DPHs) for overcoming the limit of the space-bandwidth product(SBP) delivered by existing methods. To construct DPHs, two spatially macro-pixel encoded phase components are employed in the SBP-preserved resampling of complex holograms. Four generated sub-DPHs are displayed sequentially in time for high-quality holographic image reconstruction without reducing the image size or discarding any image terms when the DPHs are interweaved. The reconstructed holographic images contain more details and less speckle noise, with their signal-to-noise ratio and structure similarity index being improved by 14.64% and 78.79%,respectively.
基金supported by the Beijing Natural Science Foundation(No.4144076)the National Natural Science Foundation of China(Nos.61307077 and 61376083)+1 种基金the China Postdoctoral Science Foundation(Nos.2013M530613 and 2015T80080)supported by the EPSRC Platform Grant for Liquid Crystal Photonics(EP/F00897X/1)
文摘Wavelength-dependent birefringence and dielectric anisotropy.two major optical properties of the nematie liquid crystal materials used in phase-only liquid crystal on silicon（LCOS） devices,are measured as a function of operating temperatures.The dynamic phase modulation depth and threshold voltage of these phase-only LCOS devices are also measured in the corresponding temperature range and compared with theoretical predictions.The results show that the dynamic response time can he reduced significantly by an appropriate increase ol device operative temperature,while the necessary device elements,such as phase modulation depth and threshold voltage,can be maintained at the same time.
基金supported by the UK Engineering and Physical Sciences Research Council(EPSRC) for the support through the EPSRC Centre for Innovative Manufacturing in Ultra Precision(EP/I033491/1)
文摘A simple and effective approach is proposed to minimize the effect of unmodulated light and uneven intensity caused by the pixelated structure of the spatial light modulator in a holographic display. A more uniform image is produced by purposely shifting the holographic images of multiple reconstructed lights with different incident angles from the zero-diffraction-order and overlapping those selected different orders. The simulation and optical experimental results show that the influence of the zero-diffraction-order can be reduced, while keeping the good uniformity of the target images by this new approach.
