Wave mixing and the intricate optical interactions therein have traditionally been regarded as hallmarks of nonlinear optics.A quintessential example of wave mixing lies in the nonlocal triple correlation between the ...Wave mixing and the intricate optical interactions therein have traditionally been regarded as hallmarks of nonlinear optics.A quintessential example of wave mixing lies in the nonlocal triple correlation between the pump beam and the generated twin photons via spontaneous parametric down-conversion(SPDC).However,the SPDC process typically requires intense laser pumping and suffers from inherently low conversion efficiencies,necessitating single-photon detection.In this work,we establish that analogous triple correlations can be effectively produced using low-power continuous-wave illumination,achieved through a commercially available spatial light modulator(SLM)in a linear optical configuration.Specifically,we show how to spatially manipulate and customize this triple correlation and further investigate the applicability across diverse domains,including pattern recognition,intelligent nonlocal image processing,and sensitivity-enhanced optical metrology.Our findings establish,to our knowledge,a novel framework for classical,linear emulation of quantum and nonlinear optical information processing paradigms rooted in multi-wave mixing.展开更多
The^(229)Th nucleus has attracted considerable attention due to the existence of its low-energy isomeric state;however,direct laser excitation in ionic systems poses significant challenges for current laser technologi...The^(229)Th nucleus has attracted considerable attention due to the existence of its low-energy isomeric state;however,direct laser excitation in ionic systems poses significant challenges for current laser technologies.In the^(229)Th^(3+)ion,the electronic bridge(EB)process enables the conversion of direct laser excitation into an effective two-photon process(I_(g),6d_(3/2)→I_(g),7_(p_(1/2))→I_(m),7_(s_(1/2))),thereby circumventing the requirement for laser radiation at 148 nm.In this work,we employ many-body perturbation theory(MBPT)to calculate the hyperfine structure constants and field shift factors for several low-lying excited states of the^(229)Th^(3+)ion.By combining these theoretical results with previously reported experimental data,we predict three transition frequencies associated with the EB process in the^(229)Th^(3+)ion and identify the most suitable transition pathway for EB-assisted nuclear excitation.展开更多
45°-cut BaTiO<sub>3</sub> crystals have been studied and used for their enhanced photorefractive performance. Theoretically, BaTiO<sub>3</sub> crystal has its maximum two-wave mixing （TWM...45°-cut BaTiO<sub>3</sub> crystals have been studied and used for their enhanced photorefractive performance. Theoretically, BaTiO<sub>3</sub> crystal has its maximum two-wave mixing （TWM） gain when the grating wave vector K<sub>g</sub> is about 45° tilted with respect to its C-axis. However, for thick samples, the effective gain is usually reduced because of the fanning problem. At steady states, the effective TWM gain of a 45°-cut BaTiO<sub>3</sub> is normally展开更多
Cascaded fiber geometry with the dispersion of each fiber decreasing is proposed to enhance the multiple four-wave mixing（FWM） generation. The first fiber with relatively large dispersion initiates and accelerates t...Cascaded fiber geometry with the dispersion of each fiber decreasing is proposed to enhance the multiple four-wave mixing（FWM） generation. The first fiber with relatively large dispersion initiates and accelerates the expansion of multiple FWM, and the second fiber with small dispersion would allow the phase-matching process（thus the spectrum broadening）to keep going. Numerical and experimental results show that with this geometry not only multiple FWM expansion can be accelerated, but also the efficiency of multiple FWM products can be effectively improved with shorter fibers.展开更多
Vacancy-ordered double perovskites(VODPs)are promising alternatives to three-dimensional lead halide perovskites for optoelectronic applications.Mixing these materials creates a vast compositional space for tunable pr...Vacancy-ordered double perovskites(VODPs)are promising alternatives to three-dimensional lead halide perovskites for optoelectronic applications.Mixing these materials creates a vast compositional space for tunable properties but complicates efficient screening of target candidates.Here,we illustrate the diverse electronic and optical characteristics as well as the nonlinear mixing effects within mixed VODPs.Furthermore,inspired by the observation that all physical properties of mixed systems with limited local environment options can be uniquely determined by the information regarding atomic-site occupation,we developed a method combining data augmentation and a transformer-inspired graph neural network to effectively encodes atomic-site information in mixed systems.This approach accurately predicts band gaps and formation energies for mixed VODPs,achieving RootMean Square Errors of 21 meV and 3.9 meV/atom,respectively.Trained with samples with up-to three mixed elements and small supercells(<72 atoms),the model not only can be generalized to medium-and high-entropy systems and larger supercells(>200 atoms),but also well reproduces the bandgap bowing effect in Sn-based mixed VODPs.展开更多
基金National Natural Science Foundation of China(12274037,11735005,11654003,61675028)Science and Technology Development Fund from Macao SAR(FDCT)(0105/2023/RIA2)Interdiscipline Research Funds of Beijing Normal University。
文摘Wave mixing and the intricate optical interactions therein have traditionally been regarded as hallmarks of nonlinear optics.A quintessential example of wave mixing lies in the nonlocal triple correlation between the pump beam and the generated twin photons via spontaneous parametric down-conversion(SPDC).However,the SPDC process typically requires intense laser pumping and suffers from inherently low conversion efficiencies,necessitating single-photon detection.In this work,we establish that analogous triple correlations can be effectively produced using low-power continuous-wave illumination,achieved through a commercially available spatial light modulator(SLM)in a linear optical configuration.Specifically,we show how to spatially manipulate and customize this triple correlation and further investigate the applicability across diverse domains,including pattern recognition,intelligent nonlocal image processing,and sensitivity-enhanced optical metrology.Our findings establish,to our knowledge,a novel framework for classical,linear emulation of quantum and nonlinear optical information processing paradigms rooted in multi-wave mixing.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0920403)the National Key Research and Development Program of China(Grant No.2022YFB3904002).
文摘The^(229)Th nucleus has attracted considerable attention due to the existence of its low-energy isomeric state;however,direct laser excitation in ionic systems poses significant challenges for current laser technologies.In the^(229)Th^(3+)ion,the electronic bridge(EB)process enables the conversion of direct laser excitation into an effective two-photon process(I_(g),6d_(3/2)→I_(g),7_(p_(1/2))→I_(m),7_(s_(1/2))),thereby circumventing the requirement for laser radiation at 148 nm.In this work,we employ many-body perturbation theory(MBPT)to calculate the hyperfine structure constants and field shift factors for several low-lying excited states of the^(229)Th^(3+)ion.By combining these theoretical results with previously reported experimental data,we predict three transition frequencies associated with the EB process in the^(229)Th^(3+)ion and identify the most suitable transition pathway for EB-assisted nuclear excitation.
基金Project supported by the K.C.Wong Education Foundation. Hong Kong
文摘45°-cut BaTiO<sub>3</sub> crystals have been studied and used for their enhanced photorefractive performance. Theoretically, BaTiO<sub>3</sub> crystal has its maximum two-wave mixing （TWM） gain when the grating wave vector K<sub>g</sub> is about 45° tilted with respect to its C-axis. However, for thick samples, the effective gain is usually reduced because of the fanning problem. At steady states, the effective TWM gain of a 45°-cut BaTiO<sub>3</sub> is normally
基金supported by the National Key Scientific Instrument and Equipment Development Project,China(Grant No.2014YQ510403)the National Natural Science Foundation of China(Grant Nos.61377039 and 51527901)
文摘Cascaded fiber geometry with the dispersion of each fiber decreasing is proposed to enhance the multiple four-wave mixing（FWM） generation. The first fiber with relatively large dispersion initiates and accelerates the expansion of multiple FWM, and the second fiber with small dispersion would allow the phase-matching process（thus the spectrum broadening）to keep going. Numerical and experimental results show that with this geometry not only multiple FWM expansion can be accelerated, but also the efficiency of multiple FWM products can be effectively improved with shorter fibers.
基金support by the National Natural Science Foundation of China(12474221 and 12104080)the Guangdong Provincial Quantum Science Strategic Initiative(Grant No.GDZX2401002),and GHfund A(202407011848),Computational resources are provided by the National Supercomputer Center at Wuzhen.
文摘Vacancy-ordered double perovskites(VODPs)are promising alternatives to three-dimensional lead halide perovskites for optoelectronic applications.Mixing these materials creates a vast compositional space for tunable properties but complicates efficient screening of target candidates.Here,we illustrate the diverse electronic and optical characteristics as well as the nonlinear mixing effects within mixed VODPs.Furthermore,inspired by the observation that all physical properties of mixed systems with limited local environment options can be uniquely determined by the information regarding atomic-site occupation,we developed a method combining data augmentation and a transformer-inspired graph neural network to effectively encodes atomic-site information in mixed systems.This approach accurately predicts band gaps and formation energies for mixed VODPs,achieving RootMean Square Errors of 21 meV and 3.9 meV/atom,respectively.Trained with samples with up-to three mixed elements and small supercells(<72 atoms),the model not only can be generalized to medium-and high-entropy systems and larger supercells(>200 atoms),but also well reproduces the bandgap bowing effect in Sn-based mixed VODPs.
