Determination of Sum Squeezing of the Field Amplitude in Frequency Upconversion Process

Sum squeezing of the field amplitude is studied in the nondegenerate and degenerate frequency upconversion process under the short interaction time. It is shown that sum squeezing can be converted into normal squeezing via sum-frequency generation in the nondegenerate frequency upconversion process, while the amplitude-squared squeezing of the fundamental mode directly changed into the squeezing of the harmonic in the degenerate frequency upconversion process. All reachable conditions of uncorrelated modes for obtaining a sum squeezing in two modes and its dependence on the squeezing of individual field modes are investigated. It is found that the squeezed states are associated with large number of pump photons. It is also confirmed that the higher-order squeezing (sum squeezing) is directly associated with coupling of the field and interaction time.

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Determination of the space-charge field amplitude in polymeric photorefractive polymers

The Journal of Chemical Physics ◽

10.1063/1.2135786 ◽

2005 ◽

Vol 123 (24) ◽

pp. 244905 ◽

Cited By ~ 5

Author(s):

Ui-Jung Hwang ◽

Chil-Sung Choi ◽

Nguyen Quoc Vuong ◽

Nakjoong Kim

Keyword(s):

Space Charge ◽

Field Amplitude ◽

Space Charge Field ◽

Photorefractive Polymers ◽

Charge Field

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On the Determination of Intrinsic Properties of Ceramic High-Tc Superconductors by Ac Susceptibility Measurements

MRS Proceedings ◽

10.1557/proc-275-275 ◽

1992 ◽

Vol 275 ◽

Author(s):

F. Ludwig

Keyword(s):

Sample Size ◽

Critical State ◽

Ac Susceptibility ◽

Field Amplitude ◽

Critical State Model ◽

State Model ◽

Critical Fields ◽

Current Densities ◽

Ac Field

ABSTRACTVarious models have been proposed to interpret ac susceptibility curves measured on sintered high-To superconductors (HTSC) and to deduce parameters like critical current densities and critical fields. To get more clearness, systematic studies of position and height of the intergranular maximum in χ'' have been performed on several ceramic HTSC samples in dependence of both ac field amplitude and sample size. In the present paper, the data are used to discuss the various models proposed in the literature. It is shown that modifications of the critical state model using incorrect jc(Hi) functions as well as other interpretations of the χ'' peak yield not actually intrinsic but sample size and geometry dependent parameters. The dependence of both position and height of the intergranular maximum in χ '' on ac field amplitude and sample size can be explained in the framework of a modified critical state model using a power law for the jc(Hi) dependence.

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Transverse Susceptibility Method in Nanoparticulate Magnetic Media

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.18304 ◽

2008 ◽

Vol 8 (6) ◽

pp. 2731-2744 ◽

Cited By ~ 3

Author(s):

Dorin Cimpoesu ◽

Leonard Spinu ◽

Alexandru Stancu

Keyword(s):

Nanostructured Materials ◽

Magnetic Relaxation ◽

Reliable Method ◽

State Of The Art ◽

Systematic Errors ◽

Field Amplitude ◽

Particle Interactions ◽

Magnetic Media ◽

Ac Field

Transverse susceptibility (TS) method is a reliable method for the determination of anisotropy in nanoparticulate media. To correctly evaluate the value of anisotropy in various modern nanostructured materials, a number of theoretical problems related to the method have to be well understood to avoid significant systematic errors. This paper presents the state of the art in the TS method which includes the expression for single domain particles with any type of anisotropy, the theoretical and micromagnetic, using Landau-Lifshitz-Gilbert (LLG) equation and stochastic LLG equation studies of the effects of ac field amplitude, inter-particle interactions, and magnetic relaxation. The problem of both real and imaginary parts of the TS signal is also discussed.

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