The memory behavior in liquid crystals(LCs)that is characterized by low cost,large area,high speed,and high-density memory has evolved from a mere scientific curiosity to a technology that is being applied in a variet...The memory behavior in liquid crystals(LCs)that is characterized by low cost,large area,high speed,and high-density memory has evolved from a mere scientific curiosity to a technology that is being applied in a variety of commodities.In this study,we utilized molybdenum disulfide(MoS_(2))nanoflakes as the vip in a homotropic LCs host to modulate the overall memory effect of the hybrid.It was found that the MoS₂nanoflakes within the LCs host formed agglomerates,which in turn resulted in an accelerated response of the hybrids to the external electric field.However,this process also resulted in a slight decrease in the threshold voltage.Additionally,it was observed that MoS₂nanoflakes in a LCs host tend to align homeotropically under an external electric field,thereby accelerating the refreshment of the memory behavior.The incorporation of a mass fraction of 0.1%2μm MoS₂nanoflakes into the LCs host was found to significantly reduce the refreshing memory behavior in the hybrid to 94.0 s under an external voltage of 5 V.These findings illustrate the efficacy of regulating the rate of memory behavior for a variety of potential applications.展开更多
The formation of submicrometer voids within Ce(DBM)3Phen doped poly(methyl methacrylate)(PMMA) was reported under multiphoton absorption excited by an infrared laser beam. The absorption spectra, photoluminescence and...The formation of submicrometer voids within Ce(DBM)3Phen doped poly(methyl methacrylate)(PMMA) was reported under multiphoton absorption excited by an infrared laser beam. The absorption spectra, photoluminescence and electron spin resonance (ESR) spectra before and after femtosecond laser irradiation were discussed. An ultrashort-pulsed laser beam with a pulse width of 200 femtosecond at a wavelength of 800 nm was focused into doped PMMA. The large changes in refractive index and the fluorescence associated with a void allowed conventional optical microscopy and reflection-type confocal microscopy to be used as detection methods. Voids could be arranged in a three-dimensional multilayered structure for high-density optical data storage. The separation of adjacent bits and layers were 4 and 16 μm, respectively.展开更多
Exploiting new concepts for dense, fast, and nonvolatile random access memory with reduced energy consump- tion is a significant issue for information technology. Here we design an ＇electrically written and optically...Exploiting new concepts for dense, fast, and nonvolatile random access memory with reduced energy consump- tion is a significant issue for information technology. Here we design an ＇electrically written and optically read＇ information storage device employing BiFeO3/A u heterostruetures with strong absorption resonance. The electro- optic effect is the basis for the device design, which arises from the strong absorption resonance in BiFeO3/Au heterostructures and the electrically tunable significant birefringence of the BiFeO3 film. We first construct a sim- ulation calculation of the BiFeO3/Au structure spectrum and identify absorption resonance and electro-optical modulation characteristics. Following a micro scale partition, the surface reflected light intensity of different polarization units is calculated. The results depend on electric polarization states of the BiFeO3 film, thus BiFeO3/Au heterostructures can essentially be designed as a type of electrically written and optically read infor- mation storage device by utilizing the scanning near-field optical microscopy technology based on the conductive silicon cantilever tip with nanofabricated aperture. This work will shed light on information storage technology.展开更多
The aqueous polymerization of acrylamide and crosslinking with N,N-methylenebisacrylamide afforded hydrogelsdisplaying high levels of light scattering (poor optical clarity). Enhancement of the optical clarity within ...The aqueous polymerization of acrylamide and crosslinking with N,N-methylenebisacrylamide afforded hydrogelsdisplaying high levels of light scattering (poor optical clarity). Enhancement of the optical clarity within a polyacrylamide(PAm) hydrogel was accomplished through the implementation of 'refractive index matching'. Water-soluble additives wereutilised to better match the refractive index inhomogeneities throughout a given hydrogel. This resulted in lower lightscattering within the system and hence improved clarity. Amino acids, sugars, polymers, and other water-soluble additivessuch as glycerol were investigated by this methodology. Most additives investigaed displayed potential for effectivelyreducing the light scattering within a PAm hydrogel as a function of increased additive concentration. On increasing therefractive index of the water medium, the overall refractive index of a PAm hydrogel was also observed to increase. Thisprovided a quantitative means of determining the effectiveness of a given additive for improving the optical clarity within ahydrogel.展开更多
Based on new obtained analytical results,the main properties of photon echo quantum memory protocols are analysed and discussed together with recently achieved experimental results.The main attention is paid to studyi...Based on new obtained analytical results,the main properties of photon echo quantum memory protocols are analysed and discussed together with recently achieved experimental results.The main attention is paid to studying the influence of spectral dispersion and nonlinear interaction of light pulses with resonant atoms.The distinctive features of the effect of spectral dispersion on the quantum storage of broadband signal pulses in the studied echo protocols are identified and discussed.Using photon echo area theorem,closed analytical solutions for echo protocols of quantum memory are obtained,describing the storage of weak and intense signal pulses,allowing us to find the conditions for the implementation of high efficiency in the echo protocols under strong nonlinear interaction of signal and control pulses with atoms.The key existing practical problems and the ways to solve them in realistic experimental conditions are outlined.We also briefly discuss the potential of using the considered photon echo quantum memory protocols in a quantum repeater.展开更多
We propose an efficient scheme for optimizing the optical memory of a sequence of signal light pulses in a system of ultracold atoms in ∧ configuration.The memory procedure consists of write-in,storage,and retrieval ...We propose an efficient scheme for optimizing the optical memory of a sequence of signal light pulses in a system of ultracold atoms in ∧ configuration.The memory procedure consists of write-in,storage,and retrieval phases.By applying a weak microwave field in the storage stage,additional phase-dependent terms are included,and the contrast of the output signal pulses can be dynamically controlled（enhanced or suppressed） through manipulating the relative phase φ between optical and microwave fields.Our numerical analysis shows that the contrast is enhanced to the most extent when φ = 1.5π.In addition,the contrast is in proportion to the Rabi frequency of the microwave field with a certain relative phase.展开更多
Temperature,as a measure of thermal motion,is a significant parameter characterizing a cold atomic ensemble optical quantum memory.In a cold gas,storage lifetime strongly depends on its temperature and is associated w...Temperature,as a measure of thermal motion,is a significant parameter characterizing a cold atomic ensemble optical quantum memory.In a cold gas,storage lifetime strongly depends on its temperature and is associated with the spin wave decoherence.Here we experimentally demonstrate a new spin wave thermometry method relying on this direct dependence.The short-wavelength spin waves resulting from the counter-propagating configuration of the control and the probe laser beams make this thermometry highly suitable for probing in situ the atomic motion in elongated clouds as the ones used in quantum memories.Our technique is realized with comparable precision for memories that rely on electromagnetically induced transparency as well as far-detuned Raman storage.展开更多
Transparent electro-optic(EO)oxide ceramics are known for their rapid EO effects.EO ceramics have several advantages over single-crystals,including variable size and shape,controllable chemical composition,superior me...Transparent electro-optic(EO)oxide ceramics are known for their rapid EO effects.EO ceramics have several advantages over single-crystals,including variable size and shape,controllable chemical composition,superior mechanical properties,and low cost.Synthesis of high-performance transparent EO ceramics requires high purity of raw materials,high density,homogeneous composition,uniform grain size,and relatively wide bandgap.Powder synthesis and sintering are two of the critical steps involved in the fabrication of highly transparent EO ceramics.Using high-activity precursor powders has been effective in fabricating high-density ceramics that demonstrate excellent EO performance.The sintering process plays a crucial role in achieving this result,and currently,there are several sintering methods available for producing high-density ceramics,including hot-pressing,hot isostatic pressing,and spark plasma sintering.This review summarizes the recent progress in materials and processes used to develop transparent EO ceramics,including those based on lead zirconate titanate,lead magnesium niobate-lead titanate,and lead-free potassium sodium niobate.In addition,several novel applications of transparent EO ceramics,including light shutters,spectral filters,optical memory,as well as image storage and displays are reviewed.In the end,the review concludes with a discussion of future trends and perspectives.展开更多
Holographic data storage system （HDSS） has been a good candidate for a volumetric recording technology, due to their large storage capacities and high transfer rates, and have been researched for tens of years after...Holographic data storage system （HDSS） has been a good candidate for a volumetric recording technology, due to their large storage capacities and high transfer rates, and have been researched for tens of years after the principle of holography was first proposed. However, these systems, called conventional 2-axis holography, still have essential issues for commercialization of products. Collinear HDSS, in which the information and reference beams are modulated co-axially by the same spatial light modulator （SLM）, as a new read/write method for HDSS are very promising. With this unique configuration, the optical pickup can be designed as small as DVDs, and can be placed on one side of the recording media （disc）. In the disc structure, the preformatted reflective layer is used for the focus/tracking servo and reading address information, and a dichroic mirror layer is used for detecting holographic recording information without interfering with the preformatted information. A 2-dimensional digital page data format is used and the shift-multiplexing method is employed to increase recording density. As servo technologies are being introduced to control the objective lens to be maintained precisely to the disc in the recording and reconstructing process, a vibration isolator is no longer necessary. Collinear holography can produce a small, practical HDSS more easily than conventional 2-axis holography. In this paper, we introduced the principle of the collinear holography and its media structure of disc. Some results of experimental and theoretical studies suggest that it is a very effective method. We also discussed some methods to increase the recording density and data transfer rates of collinear holography.展开更多
文摘The memory behavior in liquid crystals(LCs)that is characterized by low cost,large area,high speed,and high-density memory has evolved from a mere scientific curiosity to a technology that is being applied in a variety of commodities.In this study,we utilized molybdenum disulfide(MoS_(2))nanoflakes as the vip in a homotropic LCs host to modulate the overall memory effect of the hybrid.It was found that the MoS₂nanoflakes within the LCs host formed agglomerates,which in turn resulted in an accelerated response of the hybrids to the external electric field.However,this process also resulted in a slight decrease in the threshold voltage.Additionally,it was observed that MoS₂nanoflakes in a LCs host tend to align homeotropically under an external electric field,thereby accelerating the refreshment of the memory behavior.The incorporation of a mass fraction of 0.1%2μm MoS₂nanoflakes into the LCs host was found to significantly reduce the refreshing memory behavior in the hybrid to 94.0 s under an external voltage of 5 V.These findings illustrate the efficacy of regulating the rate of memory behavior for a variety of potential applications.
基金Project supported by the Shanxi (20072194 and 20072185) Provincial Youth Technology Research Foundation of China
文摘The formation of submicrometer voids within Ce(DBM)3Phen doped poly(methyl methacrylate)(PMMA) was reported under multiphoton absorption excited by an infrared laser beam. The absorption spectra, photoluminescence and electron spin resonance (ESR) spectra before and after femtosecond laser irradiation were discussed. An ultrashort-pulsed laser beam with a pulse width of 200 femtosecond at a wavelength of 800 nm was focused into doped PMMA. The large changes in refractive index and the fluorescence associated with a void allowed conventional optical microscopy and reflection-type confocal microscopy to be used as detection methods. Voids could be arranged in a three-dimensional multilayered structure for high-density optical data storage. The separation of adjacent bits and layers were 4 and 16 μm, respectively.
基金Supported by the National Natural Science Foundation of China under Grant No 11304384the Research Project of National University of Defense Technology under Grant No JC13-07-02
文摘Exploiting new concepts for dense, fast, and nonvolatile random access memory with reduced energy consump- tion is a significant issue for information technology. Here we design an ＇electrically written and optically read＇ information storage device employing BiFeO3/A u heterostruetures with strong absorption resonance. The electro- optic effect is the basis for the device design, which arises from the strong absorption resonance in BiFeO3/Au heterostructures and the electrically tunable significant birefringence of the BiFeO3 film. We first construct a sim- ulation calculation of the BiFeO3/Au structure spectrum and identify absorption resonance and electro-optical modulation characteristics. Following a micro scale partition, the surface reflected light intensity of different polarization units is calculated. The results depend on electric polarization states of the BiFeO3 film, thus BiFeO3/Au heterostructures can essentially be designed as a type of electrically written and optically read infor- mation storage device by utilizing the scanning near-field optical microscopy technology based on the conductive silicon cantilever tip with nanofabricated aperture. This work will shed light on information storage technology.
基金This work was financially supported through a sub-contract from Syracuse University under contract F30602-98C-0105
文摘The aqueous polymerization of acrylamide and crosslinking with N,N-methylenebisacrylamide afforded hydrogelsdisplaying high levels of light scattering (poor optical clarity). Enhancement of the optical clarity within a polyacrylamide(PAm) hydrogel was accomplished through the implementation of 'refractive index matching'. Water-soluble additives wereutilised to better match the refractive index inhomogeneities throughout a given hydrogel. This resulted in lower lightscattering within the system and hence improved clarity. Amino acids, sugars, polymers, and other water-soluble additivessuch as glycerol were investigated by this methodology. Most additives investigaed displayed potential for effectivelyreducing the light scattering within a PAm hydrogel as a function of increased additive concentration. On increasing therefractive index of the water medium, the overall refractive index of a PAm hydrogel was also observed to increase. Thisprovided a quantitative means of determining the effectiveness of a given additive for improving the optical clarity within ahydrogel.
基金the support of the Ministry of Science and Higher Education of the Russian Federation(Register No.121020400113-1).
文摘Based on new obtained analytical results,the main properties of photon echo quantum memory protocols are analysed and discussed together with recently achieved experimental results.The main attention is paid to studying the influence of spectral dispersion and nonlinear interaction of light pulses with resonant atoms.The distinctive features of the effect of spectral dispersion on the quantum storage of broadband signal pulses in the studied echo protocols are identified and discussed.Using photon echo area theorem,closed analytical solutions for echo protocols of quantum memory are obtained,describing the storage of weak and intense signal pulses,allowing us to find the conditions for the implementation of high efficiency in the echo protocols under strong nonlinear interaction of signal and control pulses with atoms.The key existing practical problems and the ways to solve them in realistic experimental conditions are outlined.We also briefly discuss the potential of using the considered photon echo quantum memory protocols in a quantum repeater.
基金Project supported by the National Natural Science Foundation of China(Grant No.11104112)the National Foundation for Fostering Talents of Basic Science,China(Grant No.J1103202)+2 种基金the China Postdoctoral Science Foundation(Grant No.20110491316)the National Undergraduate Innovation Foundation of China(Grant No.2011A32045)the Basic Scientific Research Foundation of Jilin University,China
文摘We propose an efficient scheme for optimizing the optical memory of a sequence of signal light pulses in a system of ultracold atoms in ∧ configuration.The memory procedure consists of write-in,storage,and retrieval phases.By applying a weak microwave field in the storage stage,additional phase-dependent terms are included,and the contrast of the output signal pulses can be dynamically controlled（enhanced or suppressed） through manipulating the relative phase φ between optical and microwave fields.Our numerical analysis shows that the contrast is enhanced to the most extent when φ = 1.5π.In addition,the contrast is in proportion to the Rabi frequency of the microwave field with a certain relative phase.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12074171,12074168,92265109,and 12204227)the Key Laboratory Fund from Guangdong Province,China(Grant No.2019B121203002)the Natural Science Foundation of Guangdong Province,China(Grant Nos.2022B1515020096 and 2019ZT08X324).
文摘Temperature,as a measure of thermal motion,is a significant parameter characterizing a cold atomic ensemble optical quantum memory.In a cold gas,storage lifetime strongly depends on its temperature and is associated with the spin wave decoherence.Here we experimentally demonstrate a new spin wave thermometry method relying on this direct dependence.The short-wavelength spin waves resulting from the counter-propagating configuration of the control and the probe laser beams make this thermometry highly suitable for probing in situ the atomic motion in elongated clouds as the ones used in quantum memories.Our technique is realized with comparable precision for memories that rely on electromagnetically induced transparency as well as far-detuned Raman storage.
文摘Transparent electro-optic(EO)oxide ceramics are known for their rapid EO effects.EO ceramics have several advantages over single-crystals,including variable size and shape,controllable chemical composition,superior mechanical properties,and low cost.Synthesis of high-performance transparent EO ceramics requires high purity of raw materials,high density,homogeneous composition,uniform grain size,and relatively wide bandgap.Powder synthesis and sintering are two of the critical steps involved in the fabrication of highly transparent EO ceramics.Using high-activity precursor powders has been effective in fabricating high-density ceramics that demonstrate excellent EO performance.The sintering process plays a crucial role in achieving this result,and currently,there are several sintering methods available for producing high-density ceramics,including hot-pressing,hot isostatic pressing,and spark plasma sintering.This review summarizes the recent progress in materials and processes used to develop transparent EO ceramics,including those based on lead zirconate titanate,lead magnesium niobate-lead titanate,and lead-free potassium sodium niobate.In addition,several novel applications of transparent EO ceramics,including light shutters,spectral filters,optical memory,as well as image storage and displays are reviewed.In the end,the review concludes with a discussion of future trends and perspectives.
文摘Holographic data storage system （HDSS） has been a good candidate for a volumetric recording technology, due to their large storage capacities and high transfer rates, and have been researched for tens of years after the principle of holography was first proposed. However, these systems, called conventional 2-axis holography, still have essential issues for commercialization of products. Collinear HDSS, in which the information and reference beams are modulated co-axially by the same spatial light modulator （SLM）, as a new read/write method for HDSS are very promising. With this unique configuration, the optical pickup can be designed as small as DVDs, and can be placed on one side of the recording media （disc）. In the disc structure, the preformatted reflective layer is used for the focus/tracking servo and reading address information, and a dichroic mirror layer is used for detecting holographic recording information without interfering with the preformatted information. A 2-dimensional digital page data format is used and the shift-multiplexing method is employed to increase recording density. As servo technologies are being introduced to control the objective lens to be maintained precisely to the disc in the recording and reconstructing process, a vibration isolator is no longer necessary. Collinear holography can produce a small, practical HDSS more easily than conventional 2-axis holography. In this paper, we introduced the principle of the collinear holography and its media structure of disc. Some results of experimental and theoretical studies suggest that it is a very effective method. We also discussed some methods to increase the recording density and data transfer rates of collinear holography.
