Colloidal Au and poly（vinylpyrrolidone） （PVP） composite thin films are fabricated by spin-coating method. Linear optical absorption measurements of the Au/PVP composite films indicate an absorption peak around 530...Colloidal Au and poly（vinylpyrrolidone） （PVP） composite thin films are fabricated by spin-coating method. Linear optical absorption measurements of the Au/PVP composite films indicate an absorption peak around 530 nm due to the surface plasmon resonance of gold nanoparticles. Nonlinear optical properties are studied using standard Z-scan technique, and experimental results show large optical nonlinearities of the Au/PVP composite films. A large value of χ^（3）/α up to 0.56× 10-^10esu·cm is obtained, which is comparable to the best values reported in metal/oxlde composite films.展开更多
40 Li_(2)O–5WO_(3)–(55-x)B_(2)O_(3):xV_(2)O_(5)(mol%)for 0.0≤x≤0.8 glasses were prepared by melt-quenching.Electric polarization was described in terms of the dielectric constant("0)and loss(tanδ).Mixed cond...40 Li_(2)O–5WO_(3)–(55-x)B_(2)O_(3):xV_(2)O_(5)(mol%)for 0.0≤x≤0.8 glasses were prepared by melt-quenching.Electric polarization was described in terms of the dielectric constant("0)and loss(tanδ).Mixed conduction phenomenon was explained by redox pairs V^(4+)↔V^(5+)and W^(5+)↔W^(6+) at high temperatures.Electronic polarizability(αe)was determined over a range of frequencies(100 Hz–100 kHz)and temperatures(30–280℃).The change of boron coordination in the glass network was explained with the aid of temperature coefficient of polarizability(φ).Nonlinear susceptibility(χ^((3)))and optical band gap(E°)were studied as a function of concentration of V_(2)O_(5).The highest values ofαe andχ^((3))were obtained at x=0.6 mol%.These glasses may find potential practical applications in the fields of solid-state ionics and nonlinear optics.展开更多
The second-order nonlinear optical susceptibilities β, βμ, and third-order non-linear optical susceptibilities γ, 〈γ〉 of a series of the novel push-pull multi-ring electro-photo polymer intermediates have been ...The second-order nonlinear optical susceptibilities β, βμ, and third-order non-linear optical susceptibilities γ, 〈γ〉 of a series of the novel push-pull multi-ring electro-photo polymer intermediates have been calculated. The influences of molecular structure, donor, acceptor and the frequency of external field on β and γ, and the relationship between γ and the number of thiophene rings (i. e. conjugated chain length) have been studied using INDO/SCI methods combined with sum-overstate (SOS) formula. The calculated results show that γ is proportional to 2.69 power of the chain length of the conjugated molecular bonds when the length is not quite long.展开更多
文摘Colloidal Au and poly（vinylpyrrolidone） （PVP） composite thin films are fabricated by spin-coating method. Linear optical absorption measurements of the Au/PVP composite films indicate an absorption peak around 530 nm due to the surface plasmon resonance of gold nanoparticles. Nonlinear optical properties are studied using standard Z-scan technique, and experimental results show large optical nonlinearities of the Au/PVP composite films. A large value of χ^（3）/α up to 0.56× 10-^10esu·cm is obtained, which is comparable to the best values reported in metal/oxlde composite films.
基金The authors wish to thank management of VNRVJIET for their support to accomplish this research work.And,the authors(Dr.L.Srinivasa Rao and Dr.P.Raghavendra Rao)would like to thank Jawaharlal Nehru Technological Uni-versity Hyderabad for awarding a research project(Proc.No.JNTUH/TEQIP-III/CRS/2019/Physics/06).
文摘40 Li_(2)O–5WO_(3)–(55-x)B_(2)O_(3):xV_(2)O_(5)(mol%)for 0.0≤x≤0.8 glasses were prepared by melt-quenching.Electric polarization was described in terms of the dielectric constant("0)and loss(tanδ).Mixed conduction phenomenon was explained by redox pairs V^(4+)↔V^(5+)and W^(5+)↔W^(6+) at high temperatures.Electronic polarizability(αe)was determined over a range of frequencies(100 Hz–100 kHz)and temperatures(30–280℃).The change of boron coordination in the glass network was explained with the aid of temperature coefficient of polarizability(φ).Nonlinear susceptibility(χ^((3)))and optical band gap(E°)were studied as a function of concentration of V_(2)O_(5).The highest values ofαe andχ^((3))were obtained at x=0.6 mol%.These glasses may find potential practical applications in the fields of solid-state ionics and nonlinear optics.
基金Project supported by the National Natural Science Foundation of China (No. 29890210)
文摘The second-order nonlinear optical susceptibilities β, βμ, and third-order non-linear optical susceptibilities γ, 〈γ〉 of a series of the novel push-pull multi-ring electro-photo polymer intermediates have been calculated. The influences of molecular structure, donor, acceptor and the frequency of external field on β and γ, and the relationship between γ and the number of thiophene rings (i. e. conjugated chain length) have been studied using INDO/SCI methods combined with sum-overstate (SOS) formula. The calculated results show that γ is proportional to 2.69 power of the chain length of the conjugated molecular bonds when the length is not quite long.
