The optical parametric oscillator (OPO) based on the periodically poled lithium tantalate (PPLT) crystal (40 mm×5 mm×1 mm) is fabricated. The OPO is pumped by a Q-switched Nd:YAG laser working at 1.064 μm. ...The optical parametric oscillator (OPO) based on the periodically poled lithium tantalate (PPLT) crystal (40 mm×5 mm×1 mm) is fabricated. The OPO is pumped by a Q-switched Nd:YAG laser working at 1.064 μm. An average idler output power (around 3.8 μm) of 1.2 W and signal output power (around 1.48 μm) of 3 W are obtained when the pump power is 20 W.展开更多
Overlaying commensurate optical lattices with various configurations called superlattices can lead to exotic lattice topologies and, in turn, a discovery of novel physics. In this study, by overlapping the maxima of l...Overlaying commensurate optical lattices with various configurations called superlattices can lead to exotic lattice topologies and, in turn, a discovery of novel physics. In this study, by overlapping the maxima of lattices, a new isolated structure is created, while the interference of minima can generate various ＂sublattice＂ patterns. Three different kinds of primitive lattices are used to demonstrate isolated square, triangular, and hexagonal ＂sublattice＂ structures in a two-dimensional optical superlattice, the patterns of which can be manipulated dynamically by tuning the polarization, frequency, and intensity of laser beams. In addition, we propose the method of altering the relative phase to adjust the tunneling amplitudes in ＂sublattices＇. Our configurations provide unique opportunities to study particle entanglement in ＂lattices＂ formed by intersecting wells and to implement special quantum logic gates in exotic lattice geometries.展开更多
In this paper,based on the one-dimensional（1D） optical superlattice model,we calculate the average reflectivities（ARs） of leaded ancient pottery（AP） made within the last 2000 years,and find that for incident lig...In this paper,based on the one-dimensional（1D） optical superlattice model,we calculate the average reflectivities（ARs） of leaded ancient pottery（AP） made within the last 2000 years,and find that for incident light with a suitable wavelength,the AR of the leaded AP increases monotonously with the increase in the layer number of the silvery glaze（SG） media.Based on this property,we propose an optical nondestructive method for identifying the age of leaded AP by detecting the AR.By using the exhaust algorithm and the discriminant function of variance,we obtain the optimal wavelength range of the incident light to identify the ages of the leaded AP.It is found that in the visible light band,if we choose green light with a wavelength range of 540-540.1 nm as the incident light,leaded AP made within the last 2000 years can be identified swiftly and precisely by detecting the ARs.This will be useful for designing optical instruments for the fast nondestructive identification of the ages of leaded AP.展开更多
We present a theoretical investigation,based on the tight-binding Hamiltonian,of efficient second-and third-order nonlinear optical processes in the lattice-matched undoped(GaP)N/(Si 2)M short-period superlattice that...We present a theoretical investigation,based on the tight-binding Hamiltonian,of efficient second-and third-order nonlinear optical processes in the lattice-matched undoped(GaP)N/(Si 2)M short-period superlattice that is waveguide-integrated in a microring resonator on an opto-electronic chip.The nonlinear superlattice structures are sit-uated on the optically pumped input area of a heterogeneous“XOI”chip based on silicon.The spectra ofχ(2)zzz(2ω,ω,ω),χ(2)xzx(2ω,ω,ω),χ(3)xxxx(3ω,ω,ω,ω)and the Kerr refractive index(n 2),have been simu-lated as a function of the number of the atomic monolayers for“non-relaxed”heterointerfaces;These nonlinearities are induced by transi-tions between valence and conduction bands.The large obtained val-ues make the(GaP)N/(Si 2)M short-period superlattice a good can-didate for future high-performance XOI photonic integrated chips that may include Si 3 N 4 or SiC or AlGaAs or Si.Near or at the 810-nm and 1550-nm wavelengths,we have made detailed calculations of the efficiency of second-and third-harmonic generation as well as the performances of entangled photon-pair quantum sources that are based upon spontaneous parametric down conversion and sponta-neous four-wave mixing.The results indicate that the(GaP)N/(Si 2)M short-period superlattice is competitive with present technologies and is practical for classical and quantum applications.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 10534020)the National Key Projects for Basic Research of China (Grant No. 2006CB921804)
文摘The optical parametric oscillator (OPO) based on the periodically poled lithium tantalate (PPLT) crystal (40 mm×5 mm×1 mm) is fabricated. The OPO is pumped by a Q-switched Nd:YAG laser working at 1.064 μm. An average idler output power (around 3.8 μm) of 1.2 W and signal output power (around 1.48 μm) of 3 W are obtained when the pump power is 20 W.
基金Acknowledgements This work was supported by the National Key Research and Development Program of China （Grant No. 2016YFA0301501）, and the National Natural Science Foundation of China （Grants Nos. 61475007, 11334001, and 91336103）.
文摘Overlaying commensurate optical lattices with various configurations called superlattices can lead to exotic lattice topologies and, in turn, a discovery of novel physics. In this study, by overlapping the maxima of lattices, a new isolated structure is created, while the interference of minima can generate various ＂sublattice＂ patterns. Three different kinds of primitive lattices are used to demonstrate isolated square, triangular, and hexagonal ＂sublattice＂ structures in a two-dimensional optical superlattice, the patterns of which can be manipulated dynamically by tuning the polarization, frequency, and intensity of laser beams. In addition, we propose the method of altering the relative phase to adjust the tunneling amplitudes in ＂sublattices＇. Our configurations provide unique opportunities to study particle entanglement in ＂lattices＂ formed by intersecting wells and to implement special quantum logic gates in exotic lattice geometries.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10974061)
文摘In this paper,based on the one-dimensional（1D） optical superlattice model,we calculate the average reflectivities（ARs） of leaded ancient pottery（AP） made within the last 2000 years,and find that for incident light with a suitable wavelength,the AR of the leaded AP increases monotonously with the increase in the layer number of the silvery glaze（SG） media.Based on this property,we propose an optical nondestructive method for identifying the age of leaded AP by detecting the AR.By using the exhaust algorithm and the discriminant function of variance,we obtain the optimal wavelength range of the incident light to identify the ages of the leaded AP.It is found that in the visible light band,if we choose green light with a wavelength range of 540-540.1 nm as the incident light,leaded AP made within the last 2000 years can be identified swiftly and precisely by detecting the ARs.This will be useful for designing optical instruments for the fast nondestructive identification of the ages of leaded AP.
基金The work of Richard Soref is supported by the Air Force Office of Scientific Research under Grant FA9550-21-1-0347.
文摘We present a theoretical investigation,based on the tight-binding Hamiltonian,of efficient second-and third-order nonlinear optical processes in the lattice-matched undoped(GaP)N/(Si 2)M short-period superlattice that is waveguide-integrated in a microring resonator on an opto-electronic chip.The nonlinear superlattice structures are sit-uated on the optically pumped input area of a heterogeneous“XOI”chip based on silicon.The spectra ofχ(2)zzz(2ω,ω,ω),χ(2)xzx(2ω,ω,ω),χ(3)xxxx(3ω,ω,ω,ω)and the Kerr refractive index(n 2),have been simu-lated as a function of the number of the atomic monolayers for“non-relaxed”heterointerfaces;These nonlinearities are induced by transi-tions between valence and conduction bands.The large obtained val-ues make the(GaP)N/(Si 2)M short-period superlattice a good can-didate for future high-performance XOI photonic integrated chips that may include Si 3 N 4 or SiC or AlGaAs or Si.Near or at the 810-nm and 1550-nm wavelengths,we have made detailed calculations of the efficiency of second-and third-harmonic generation as well as the performances of entangled photon-pair quantum sources that are based upon spontaneous parametric down conversion and sponta-neous four-wave mixing.The results indicate that the(GaP)N/(Si 2)M short-period superlattice is competitive with present technologies and is practical for classical and quantum applications.
