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Title: Kramers-Kronig relations in Laser Intensity Modulation Method

Abstract

In this short paper, the Kramers-Kronig relations for the Laser Intensity Modulation Method (LIMM) are presented to check the self-consistency of experimentally obtained complex current densities. The numerical procedure yields well defined, precise estimates for the real and the imaginary parts of the LIMM current density calculated from its imaginary and real parts, respectively. The procedure also determines an accurate high frequency real current value which appears to be an intrinsic material parameter similar to that of the dielectric permittivity at optical frequencies. Note that the problem considered here couples two different material properties, thermal and electrical, consequently the validity of the Kramers-Kronig relation indicates that the problem is invariant and linear.

Authors:
 [1]
  1. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
OE USDOE - Office of Electric Transmission and Distribution
OSTI Identifier:
1003618
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review B; Journal Volume: 74; Journal Issue: 11
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CURRENT DENSITY; DIELECTRIC MATERIALS; LASERS; MODULATION; PERMITTIVITY

Citation Formats

Tuncer, Enis. Kramers-Kronig relations in Laser Intensity Modulation Method. United States: N. p., 2006. Web. doi:10.1103/PhysRevB.74.113109.
Tuncer, Enis. Kramers-Kronig relations in Laser Intensity Modulation Method. United States. doi:10.1103/PhysRevB.74.113109.
Tuncer, Enis. Sun . "Kramers-Kronig relations in Laser Intensity Modulation Method". United States. doi:10.1103/PhysRevB.74.113109.
@article{osti_1003618,
title = {Kramers-Kronig relations in Laser Intensity Modulation Method},
author = {Tuncer, Enis},
abstractNote = {In this short paper, the Kramers-Kronig relations for the Laser Intensity Modulation Method (LIMM) are presented to check the self-consistency of experimentally obtained complex current densities. The numerical procedure yields well defined, precise estimates for the real and the imaginary parts of the LIMM current density calculated from its imaginary and real parts, respectively. The procedure also determines an accurate high frequency real current value which appears to be an intrinsic material parameter similar to that of the dielectric permittivity at optical frequencies. Note that the problem considered here couples two different material properties, thermal and electrical, consequently the validity of the Kramers-Kronig relation indicates that the problem is invariant and linear.},
doi = {10.1103/PhysRevB.74.113109},
journal = {Physical Review B},
number = 11,
volume = 74,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}
  • In principle the conductivity of the cuprate superconductors can be obtained from reflectivity measurements using the Kramers-Kronig-transform technique. However, at low temperatures and for frequencies below [similar to]300 cm[sup [minus]1] the reflectivities of materials such as YBa[sub 2]Cu[sub 3]O[sub 7] are close to unity. Uncertainty in the precise signal level corresponding to unity reflectivity and a lack of knowledge of the reflectivity below the lowest measured frequency cause this method to become unreliable. To address this problem we have used a bolometric technique and a resonant technique to obtain accurate submillimeter and microwave data for the residual losses in epitaxialmore » thin films of YBa[sub 2]Cu[sub 3]O[sub 7] at low temperatures. The Kramers-Kronig analysis of our data is in good agreement with results from fitting our data to simple weakly coupled grain and two-fluid models for the [ital a]-[ital b] plane conductivity. However, below 450 cm[sup [minus]1] it is in disagreement with some published results of other workers obtained from Kramers-Kronig analysis of reflectivity data. To understand this discrepancy we analyze how the conductivity determined by the Kramers-Kronig-transform technique depends on some commonly used low-frequency extrapolations of reflectivity data.« less
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