基于光通信系统对于全光调制和全光开关等的需求,从理论上和实验上研究了拉曼增益对回音壁模式光学微腔系统共振模式的全光调制。理论分析表明,拉曼增益能够补偿回音壁模式光学微腔系统的损耗,进而改变微腔系统的耦合机制,在不对微腔系...基于光通信系统对于全光调制和全光开关等的需求,从理论上和实验上研究了拉曼增益对回音壁模式光学微腔系统共振模式的全光调制。理论分析表明,拉曼增益能够补偿回音壁模式光学微腔系统的损耗,进而改变微腔系统的耦合机制,在不对微腔系统做任何机械性移动的前提下实现对系统共振透射率的连续调制。实验中采用光纤锥耦合的二氧化硅微芯圆环腔,利用560μW的低功率泵浦光引发的拉曼散射,波长为1 545.7 nm的信号光实现了13.5 d B的调制度,使得系统的耦合机制由欠耦合转化为临界耦合。展开更多
Although vast amounts of information are conveyed by photons in optical fibers,the majority of data processing is performed electronically,creating the infamous‘information bottleneck’and consuming energy at an incr...Although vast amounts of information are conveyed by photons in optical fibers,the majority of data processing is performed electronically,creating the infamous‘information bottleneck’and consuming energy at an increasingly unsustainable rate.The potential for photonic devices to directly manipulate light remains unfulfilled due largely to a lack of materials with strong,fast optical nonlinearities.In this paper,we show that small-signal amplifier,summator and invertor functions for optical signals may be realized using a four-port device that exploits the coherent interaction of beams on a planar plasmonic metamaterial,assuming no intrinsic nonlinearity.The redistribution of energy among ports can provide nonlinear input-output signal dependencies and may be coherently controlled at very low intensity levels,with multi-THz bandwidth and without introducing signal distortion,thereby presenting powerful opportunities for novel optical data processing architectures,complexity oracles and the locally coherent networks that are becoming part of the mainstream telecommunications agenda.展开更多
The ability to control the wavefront of light is fundamental to focusing and redistribution of light,enabling many applications from imaging to spectroscopy.Wave interaction on highly nonlinear photorefractive materia...The ability to control the wavefront of light is fundamental to focusing and redistribution of light,enabling many applications from imaging to spectroscopy.Wave interaction on highly nonlinear photorefractive materials is essentially the only established technology allowing the dynamic control of the wavefront of a light beam with another beam of light,but it is slow and requires large optical power.Here we report a proof-of-principle demonstration of a new technology for two-dimensional(2D)control of light with light based on the coherent interaction of optical beams on highly absorbing plasmonic metasurfaces.We illustrate this by performing 2D all-optical logical operations(AND,XOR and OR)and image processing.Our approach offers diffractionlimited resolution,potentially at arbitrarily-low intensity levels and with 100 THz bandwidth,thus promising new applications in space-division multiplexing,adaptive optics,image correction,processing and recognition,2D binary optical data processing and reconfigurable optical devices.展开更多
We investigated optically controllable gray-level diffraction from a body-centered tetragonal photonic crystal that was based on an azo-dye-doped holographic polymer dispersed liquid crystal. The sample is fabricated ...We investigated optically controllable gray-level diffraction from a body-centered tetragonal photonic crystal that was based on an azo-dye-doped holographic polymer dispersed liquid crystal. The sample is fabricated by use of two-beam interference with multi-exposure. Bichromatic pumping beams at various intensities were used to pump the sample to change the concentration of the cis isomer and, in turn, modulate the effective index of the photonic crystals as well as their diffraction intensity. Three pumping processes were utilized to produce gray-level switching of diffractive light. This study demonstrates the optimum gray-level to be 15-level of up-step and down-step. The simulation of the diffraction intensity under bichromatic pumping sources was also studied.展开更多
Vision,microscopy,imaging,optical data projection and storage all depend on focusing of light.Dynamic focusing is conventionally achieved with mechanically reconfigurable lenses,spatial light modulators or microfluidi...Vision,microscopy,imaging,optical data projection and storage all depend on focusing of light.Dynamic focusing is conventionally achieved with mechanically reconfigurable lenses,spatial light modulators or microfluidics.Here we demonstrate that dynamic control of focusing can be achieved through coherent interaction of optical waves on a thin beam splitter.We use a nanostructured plasmonic metasurface of subwavelength thickness as the beam splitter,allowing operation in the regimes of coherent absorption and coherent transparency.Focusing of light resulting from illumination of the plasmonic metasurface with a Fresnel zone pattern is controlled by another patterned beam projected on the same metasurface.By altering the control pattern,its phase,or its intensity,we switch the lens function on and off,and alter the focal spot’s depth,diameter and intensity.Switching occurs as fast as the control beam is modulated and therefore tens of gigahertz modulation bandwidth is possible with electro-optical modulators,which is orders of magnitude faster than conventional dynamic focusing technologies.展开更多
文摘基于光通信系统对于全光调制和全光开关等的需求,从理论上和实验上研究了拉曼增益对回音壁模式光学微腔系统共振模式的全光调制。理论分析表明,拉曼增益能够补偿回音壁模式光学微腔系统的损耗,进而改变微腔系统的耦合机制,在不对微腔系统做任何机械性移动的前提下实现对系统共振透射率的连续调制。实验中采用光纤锥耦合的二氧化硅微芯圆环腔,利用560μW的低功率泵浦光引发的拉曼散射,波长为1 545.7 nm的信号光实现了13.5 d B的调制度,使得系统的耦合机制由欠耦合转化为临界耦合。
基金This study was supported by the Engineering and Physical Sciences Research Council(grant EP/G060363/1)the Royal Society,and the Singapore Ministry of Education[Grant MOE2011-T3-1-005]
文摘Although vast amounts of information are conveyed by photons in optical fibers,the majority of data processing is performed electronically,creating the infamous‘information bottleneck’and consuming energy at an increasingly unsustainable rate.The potential for photonic devices to directly manipulate light remains unfulfilled due largely to a lack of materials with strong,fast optical nonlinearities.In this paper,we show that small-signal amplifier,summator and invertor functions for optical signals may be realized using a four-port device that exploits the coherent interaction of beams on a planar plasmonic metamaterial,assuming no intrinsic nonlinearity.The redistribution of energy among ports can provide nonlinear input-output signal dependencies and may be coherently controlled at very low intensity levels,with multi-THz bandwidth and without introducing signal distortion,thereby presenting powerful opportunities for novel optical data processing architectures,complexity oracles and the locally coherent networks that are becoming part of the mainstream telecommunications agenda.
基金supported by the UK’s Defence Science and Technology Laboratory(Grant DSTLX1000064081)the MOE Singapore(Grant MOE2011-T3-1-005)+2 种基金the Leverhulme Trustthe University of Southampton Enterprise Fundthe UK’s Engineering and Physical Sciences Research Council(Grant EP/G060363/1)。
文摘The ability to control the wavefront of light is fundamental to focusing and redistribution of light,enabling many applications from imaging to spectroscopy.Wave interaction on highly nonlinear photorefractive materials is essentially the only established technology allowing the dynamic control of the wavefront of a light beam with another beam of light,but it is slow and requires large optical power.Here we report a proof-of-principle demonstration of a new technology for two-dimensional(2D)control of light with light based on the coherent interaction of optical beams on highly absorbing plasmonic metasurfaces.We illustrate this by performing 2D all-optical logical operations(AND,XOR and OR)and image processing.Our approach offers diffractionlimited resolution,potentially at arbitrarily-low intensity levels and with 100 THz bandwidth,thus promising new applications in space-division multiplexing,adaptive optics,image correction,processing and recognition,2D binary optical data processing and reconfigurable optical devices.
文摘We investigated optically controllable gray-level diffraction from a body-centered tetragonal photonic crystal that was based on an azo-dye-doped holographic polymer dispersed liquid crystal. The sample is fabricated by use of two-beam interference with multi-exposure. Bichromatic pumping beams at various intensities were used to pump the sample to change the concentration of the cis isomer and, in turn, modulate the effective index of the photonic crystals as well as their diffraction intensity. Three pumping processes were utilized to produce gray-level switching of diffractive light. This study demonstrates the optimum gray-level to be 15-level of up-step and down-step. The simulation of the diffraction intensity under bichromatic pumping sources was also studied.
基金supported by the University of Southampton Enterprise Fund,the UK's Engineering and Physical Sciences Research Council(grant EP/M009122/1)the MOE Singapore(grant MOE2011-T3-1-005)。
文摘Vision,microscopy,imaging,optical data projection and storage all depend on focusing of light.Dynamic focusing is conventionally achieved with mechanically reconfigurable lenses,spatial light modulators or microfluidics.Here we demonstrate that dynamic control of focusing can be achieved through coherent interaction of optical waves on a thin beam splitter.We use a nanostructured plasmonic metasurface of subwavelength thickness as the beam splitter,allowing operation in the regimes of coherent absorption and coherent transparency.Focusing of light resulting from illumination of the plasmonic metasurface with a Fresnel zone pattern is controlled by another patterned beam projected on the same metasurface.By altering the control pattern,its phase,or its intensity,we switch the lens function on and off,and alter the focal spot’s depth,diameter and intensity.Switching occurs as fast as the control beam is modulated and therefore tens of gigahertz modulation bandwidth is possible with electro-optical modulators,which is orders of magnitude faster than conventional dynamic focusing technologies.
