Spectroscopic polarimetry
AssigneesNational University Corporation Hokkaido University, OMRON Corporation
InventorsKazuhiko Oka, Atsushi Taniguchi, Hiroshi Okabe
Life of this patent
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Abstract
To effectively reduce a measurement error in a parameter indicating a state of spectroscopic polarization generated by variations in retardation of a retarder due to a temperature change or other factors, while holding a variety of properties of a channeled spectroscopic polarimeter. By noting that reference phase functions φ1(σ) and φ2(σ) are obtained by solving an equation from each vibration component contained in a channeled spectrum P(σ), the reference phase functions φ1(σ) and φ2(σ) are calibrated concurrently with measurement of spectrometric Stokes parameters S0(σ), S1(σ), S2(σ), and S3(σ).
Claims17
A spectroscopic polarimetry, comprising:
- a step of preparing a polarimetric spectroscope, where
- a first retarder, a second retarder and an analyzer, through which light under measurement passes in sequence, and a device for obtaining a spectral intensity of the light having passed through the analyzer are provided,
- the second retarder is arranged such that the direction of a principal axis of the second retarder disagrees with the direction of a principal axis of the first retarder, and
- the analyzer is arranged such that the direction of a transmission axis of the analyzer disagrees with the direction of the principal axis of the second retarder;
- a step of launching the light under measurement into the polarimetric spectroscope to obtain a spectral intensity;
- and
- an arithmetic step of obtaining a set of phase attribute functions of a measurement system, and also obtaining a parameter indicating a wavenumber-distribution of a state of polarization (SOP) of the light under measurement by the use of the above obtained spectral intensity, wherein
- the set of phase attribute functions is a set of functions defined by properties of the polarimetric spectroscope, and includes a function depending upon at least a first reference phase function (φ1(σ)) as retardation of the first retarder and a function depending upon at least a second reference phase function (φ2(σ)) as retardation of the second retarder, and by those functions themselves, or by addition of another function defined by the properties of the polarimetric spectroscope, the set of phase attribute functions becomes a set of functions sufficient to determine a parameter indicating a wavenumber-distribution of the SOP of the light under measurement.
A spectroscopic polarimeter, comprising:
- a polarimetric spectroscope in which
- a first retarder, a second retarder and an analyzer, through which light under measurement passes in sequence, and a device for obtaining a spectral intensity of the light having passed through the analyzer are provided,
- the second retarder is arranged such that the direction of a principal axis of the second retarder disagrees with the direction of a principal axis of the first retarder, and
- the analyzer is arranged such that the direction of a transmission axis of the analyzer disagrees with the direction of the principal axis of the second retarder;
- and
- an arithmetic unit for obtaining a set of phase attribute functions of a measurement system, and also obtaining a parameter indicating a wavenumber-distribution of a state of polarization (SOP) of the light under measurement by the use of the spectral intensity obtained by launching the light under measurement into the polarimetric spectroscope, wherein
- the set of phase attribute functions is a set of functions defined by properties of the polarimetric spectroscope, and includes a function depending upon at least a first reference phase function (φ1(σ)) as retardation of the first retarder and a function depending upon at least a second reference phase function (φ2(σ)) as retardation of the second retarder, and by those functions themselves, or by addition of another function defined by the properties of the polarimetric spectroscope, the set of phase attribute functions becomes a set of functions sufficient to determine a parameter indicating a wavenumber-distribution of the SOP of the light under measurement.
Dependencies are inferred from the claim text.