- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Recovering distance information in spectral domain interferometry
摘要： This work evaluates the performance of the Complex Master Slave (CMS) method, that processes the spectra at the interferometer output of a spectral domain interferometry device without involving Fourier transforms (FT) after data acquisition. Reliability and performance of CMS are compared side by side with the conventional method based on FT, phase calibration with dispersion compensation (PCDC). We demonstrate that both methods provide similar results in terms of resolution and sensitivity drop-off. The mathematical operations required to produce CMS results are highly parallelizable, allowing real-time, simultaneous delivery of data from several points of different optical path differences in the interferometer, not possible via PCDC.
关键词： distance measurement,spectral domain interferometry,optical coherence tomography,dispersion compensation,phase calibration,Complex Master Slave,Fourier transforms
更新于2025-09-23 15:23:52
-
The method of Fourier transforms applied to electromagnetic knots
摘要： The Fourier transform method can be applied to obtain electromagnetic knots, which are solutions of Maxwell equations in vacuum with non-trivial topology of the field lines and especial properties. The program followed in this work allows to present the main ideas and the explicit calculations at undergraduate level, so they are not obscured by a more involved formulation. We make use of helicity basis for calculating the electromagnetic helicity and the photon content of the fields.
关键词： Fourier transforms,helicity basis,Maxwell equations,electromagnetic knots,photon content
更新于2025-09-23 15:21:01
-
Accuracy of Partial Core Corrections Using Fourier Transforms in Pseudopotential–Density Functional Theory
摘要： Partial core corrections can be important in obtaining an accurate description of nonlinear exchange-correlation functionals and improving the transferability of pseudopotentials. We show that a widely used procedure, which calculates partial core charge density, ρcore partial, in Fourier space and then converts it to real space with fast Fourier transforms, can lead to sizable numerical errors of exchange-correlation potentials in the vacuum region. Such errors occur in modeling low-dimensional materials or surfaces with supercells. The loss of accuracy originates from the slow-decaying feature of core charge density in reciprocal space. Numerical errors on the order of 1 eV in the Kohn?Sham energies of unoccupied states can occur in pseudopotential?density functional calculations. The direct calculation of the partial core charge in real space can avoid the numerical errors caused by Fourier transforms.
关键词： pseudopotential?density functional theory,numerical errors,Fourier transforms,exchange-correlation potentials,partial core corrections
更新于2025-09-11 14:15:04