US 12,516,978 B2Granted

Multiphase lock-in spectrometer assembly applied to a modulated source of multi-wavelength optical radiation, and associated methods and uses

AssigneeCentre Scientifique Et Technique Du Batiment (Cstb)

InventorChristophe Martinsons

Life of this patent

Estimating the term…

Abstract

This relates to a multi-phase lock-in spectrometer assembly applied to a modulated source of multi-wavelength optical radiation, wherein the beam coming from the source is divided into two identical quadrature-modulated beams, the two beams being acquired by at least one spectrometer in order to calculate the amplitude spectrum and the phase spectrum of the modulated source of multi-wavelength optical radiation. Also disclosed are associated methods and uses.

Claims21

Dependent claims

A multiphase lock-in spectrometer assembly configured to be applied to a modulated source of multi-wavelength optical radiation, said spectrometer assembly comprising a collection assembly configured to collect multi-wavelength optical radiation emitted by the modulated source,

wherein:
the collection assembly comprises at least one collection optic and is configured to output at least two identical source optical radiation beams;
the spectrometer assembly comprises:
a lock-in assembly configured to generate at least one reference signal based on the phase and modulation frequency of the optical radiation emitted by the modulated source,
two spectrometers,
a modulation assembly configured to control, based on the at least one reference signal, an acquisition by each spectrometer of a plurality of spectra,
the spectra comprising information for at least one wavelength range of the optical radiation wavelengths,
each spectrum being measured on N time sections of source optical radiation beam, N being an integer greater than or equal to one, each time section having a duration corresponding to a period 1/fm and being spaced from a time section of the same type by a period 1/fm, fm being a frequency used to control the modulation assembly obtained from the at least one reference signal;
a first spectrometer is configured to acquire the spectra (Ii(λ), with i∈{1, . . . , N}) on first time sections, of a first of source optical radiation beam, said to be in phase relative to the optical radiation collected by the collection assembly;
a second spectrometer is configured to acquire the spectra (Qi(λ), with i∈{1, . . . , N}) on second time sections, of a second source optical radiation beam, in phase quadrature relative to the first time sections;
the first spectrometer is configured to measure, without recourse to the modulation assembly, a spectral quantity of the first source optical radiation beam (I0(λ));
the second spectrometer is configured to measure, without recourse to the modulation assembly, a spectral quantity of the second source optical radiation beam (Q0(λ));
the spectrometer assembly comprises a low-pass filter unit configured to be applied to the spectra (Ii(λ), with i∈{1, . . . , N}) in order to obtain a spectrum (I(λ)), and to be applied to the spectra (Qi(λ), with i∈{1, . . . , N}) in order to obtain a spectrum (Q(λ));
and
the spectrometer assembly comprises a calculation unit configured to calculate an amplitude spectrum (R(λ)) and a phase spectrum (θ(λ)) of the optical radiation collected by the collection assembly using the following formulae:
R
⁡
(
λ
)
=
(
I
⁡
(
λ
)
-
1
2
⁢
I
0
(
λ
)
)
2
+
(
Q
⁡
(
λ
)
-
1
2
⁢
Q
0
(
λ
)
)
2
⁢
and
Θ
⁡
(
λ
)
=
arctan
⁡
(
Q
⁡
(
λ
)
-
1
2
⁢
Q
0
(
λ
)
I
⁡
(
λ
)
-
1
2
⁢
I
0
(
λ
)
)
.

94 more elements

A multiphase lock-in spectrometer assembly configured to be applied to a modulated source of multi-wavelength optical radiation, said spectrometer assembly comprising a collection assembly configured to collect a multi-wavelength optical radiation emitted by the modulated source,

wherein:
the collection assembly comprises at least one collection optic and is configured to output at least one source optical radiation beam;
the spectrometer assembly comprises:
a lock-in assembly configured to generate a reference signal based on the phase and modulation frequency of the optical radiation emitted by the modulated source,
a single spectrometer,
a modulation assembly configured to control, based on the reference signal, an acquisition by the spectrometer of a plurality of spectra,
the spectra comprising information for at least one wavelength range of the optical radiation wavelengths,
each spectrum being measured on N time sections of the source optical radiation beam, N being an integer greater than or equal to one, each time section having a duration corresponding to a period 1/fm and being spaced from a time section of the same type by a period 1/fm, with fm a frequency used to control the modulation assembly obtained from the reference signal;
the spectrometer is configured to acquire the spectra (Ii(λ), with i∈{1, . . . , N}) on first time sections, of a first source optical radiation beam, said to be in phase relative to the optical radiation collected by the collection assembly, then the spectra (Qi(λ), with i∈{1, . . . , N}) on second time sections, of the first source optical radiation beam, in phase quadrature relative to the first time sections;
the spectrometer is configured to successively carry out, at least once, the acquisition of the spectra (Ii(λ), with i∈{1, . . . , N}) on the first time sections and the spectra (Qi(λ), with i∈{1, . . . , N}) on the second time sections;
the spectrometer is configured to measure, without recourse to the modulation assembly, a spectral quantity of the first source optical radiation beam (I0(λ)=Q0(λ));
the spectrometer assembly comprises a low-pass filter unit configured to be applied to the spectra (Ii(λ), with i∈{1, . . . , N}) in order to obtain a spectrum (I(λ)), and to be applied to the spectra (Qi(λ), with i∈{1, . . . , N}) in order to obtain a spectrum (Q(λ));
and
the spectrometer assembly comprises a calculation unit configured to calculate an amplitude spectrum (R(λ)) and a phase spectrum (θ(λ)) of the optical radiation collected by the collection assembly using the following formulae:
R
⁡
(
λ
)
=
(
I
⁡
(
λ
)
-
1
2
⁢
I
0
(
λ
)
)
2
+
(
Q
⁡
(
λ
)
-
1
2
⁢
Q
0
(
λ
)
)
2
⁢
and
Θ
⁡
(
λ
)
=
arctan
⁡
(
Q
⁡
(
λ
)
-
1
2
⁢
Q
0
(
λ
)
I
⁡
(
λ
)
-
1
2
⁢
I
0
(
λ
)
)
.

93 more elements

The multiphase lock-in spectrometer assembly configured to be applied to a modulated source of multi-wavelength optical radiation, said spectrometer assembly comprising a collection assembly configured to collect multi-wavelength optical radiation emitted by the modulated source,

wherein:
the collection assembly comprises at least one collection optic and is configured to output at least four identical source optical radiation beams;
the spectrometer assembly comprises:
a lock-in assembly configured to generate at least one reference signal based on the phase and modulation frequency of the optical radiation emitted by the modulated source,
four spectrometers,
a modulation assembly configured to control, based on the at least one reference signal, an acquisition by each spectrometer of a plurality of spectra,
the spectra comprising information for at least one wavelength range of the optical radiation wavelengths,
each spectrum being measured on N time sections of the source optical radiation beam, N being an integer greater than or equal to one, each time section having a duration corresponding to a period 1/fm and being spaced from a time section of the same type by a period 1/fm, with fm a frequency used to control the modulation assembly-obtained from the at least one reference signal;
a first spectrometer is configured to acquire the spectra (I1i(λ), with i∈{1, . . . , N}) on first time sections, of a first source optical radiation beam, said to be in phase relative to the optical radiation collected by the collection assembly;
a second spectrometer is configured to acquire the spectra (Q1i(λ), with i∈{1, . . . , N}) on second time sections, of a second source optical radiation beam, in phase quadrature and in phase advance relative to the first time sections;
a third spectrometer is configured to acquire the spectra(I2i(λ), with i∈{1, . . . , N}) on third time sections, of a third source optical radiation beam, in phase quadrature and in phase advance relative to the second time sections;
a fourth spectrometer is configured to acquire the spectra (Q2i(λ), with i∈{1, . . . , N}) on fourth time sections, of a fourth source optical radiation beam, in phase quadrature and in phase advance relative to the third time sections;
the spectrometer assembly comprises a low-pass filter unit configured to be applied to the spectra (I1i(λ), with i∈{1, . . . , N}) in order to obtain a spectrum (I1(λ)), to be applied to the spectra (Q1i(λ), with i∈{1, . . . , N}) in order to obtain a spectrum (Q1(λ)), to be applied to the spectra (I2i(λ), with i∈{1, . . . , N}) in order to obtain a spectrum (I2(λ)), and to be applied to the spectra (Q2i(λ), with i∈{1, . . . , N}) in order to obtain a spectrum (Q2(λ));
and
the spectrometer assembly comprises a calculation unit configured to calculate an amplitude spectrum (R(λ)) and a phase spectrum (θ(λ)) of the optical radiation collected by the collection assembly using the following formulae:
R
⁡
(
λ
)
=
(
I
1
(
λ
)
-
I
2
(
λ
)
)
2
+
(
Q
1
(
λ
)
-
Q
2
(
λ
)
)
2
⁢
and
Θ
⁡
(
λ
)
=
arctan
⁡
(
Q
1
(
λ
)
-
Q
2
(
λ
)
I
1
(
λ
)
-
I
2
(
λ
)
)
.

82 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/575,704Filed 20 Jun 2022
Priority: FR 210695829 Jun 2021
Published: US 2024/0337533 A110 Oct 2024
Granted: 6 Jan 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

G01J 3/10
Details: arrangements of light sources specially adapted for spectrometry or colorimetry
G01J 3/433
Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry: modulation spectrometry; Derivative spectrometry
G01J 3/0229
Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows: using masks, aperture plates, spatial light modulators or…
G01J 3/0262
Details: constructional arrangements for removing stray light

Family

US 2024/0337533 A1Pre-grant publication · published 10 Oct 2024
US 12,516,978 B2This patent

From the US filing history. Foreign family members aren’t listed.

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Abstract

wherein:
the collection assembly comprises at least one collection optic and is configured to output at least two identical source optical radiation beams;
the spectrometer assembly comprises:
a lock-in assembly configured to generate at least one reference signal based on the phase and modulation frequency of the optical radiation emitted by the modulated source,
two spectrometers,
a modulation assembly configured to control, based on the at least one reference signal, an acquisition by each spectrometer of a plurality of spectra,
the spectra comprising information for at least one wavelength range of the optical radiation wavelengths,
each spectrum being measured on N time sections of source optical radiation beam, N being an integer greater than or equal to one, each time section having a duration corresponding to a period 1/fm and being spaced from a time section of the same type by a period 1/fm, fm being a frequency used to control the modulation assembly obtained from the at least one reference signal;
a first spectrometer is configured to acquire the spectra (Ii(λ), with i∈{1, . . . , N}) on first time sections, of a first of source optical radiation beam, said to be in phase relative to the optical radiation collected by the collection assembly;
a second spectrometer is configured to acquire the spectra (Qi(λ), with i∈{1, . . . , N}) on second time sections, of a second source optical radiation beam, in phase quadrature relative to the first time sections;
the first spectrometer is configured to measure, without recourse to the modulation assembly, a spectral quantity of the first source optical radiation beam (I0(λ));
the second spectrometer is configured to measure, without recourse to the modulation assembly, a spectral quantity of the second source optical radiation beam (Q0(λ));
the spectrometer assembly comprises a low-pass filter unit configured to be applied to the spectra (Ii(λ), with i∈{1, . . . , N}) in order to obtain a spectrum (I(λ)), and to be applied to the spectra (Qi(λ), with i∈{1, . . . , N}) in order to obtain a spectrum (Q(λ));
and
the spectrometer assembly comprises a calculation unit configured to calculate an amplitude spectrum (R(λ)) and a phase spectrum (θ(λ)) of the optical radiation collected by the collection assembly using the following formulae:
R
⁡
(
λ
)
=
(
I
⁡
(
λ
)
-
1
2
⁢
I
0
(
λ
)
)
2
+
(
Q
⁡
(
λ
)
-
1
2
⁢
Q
0
(
λ
)
)
2
⁢
and
Θ
⁡
(
λ
)
=
arctan
⁡
(
Q
⁡
(
λ
)
-
1
2
⁢
Q
0
(
λ
)
I
⁡
(
λ
)
-
1
2
⁢
I
0
(
λ
)
)
.

94 more elements

Facts

Application

18/575,704Filed 20 Jun 2022

Priority

FR 210695829 Jun 2021

Published

US 2024/0337533 A110 Oct 2024

Granted

6 Jan 2026

Term ends

Not estimatedThe source records don’t support an estimate.

Classification9 codes

G01J 3/10
Details: arrangements of light sources specially adapted for spectrometry or colorimetry
G01J 3/433
Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry: modulation spectrometry; Derivative spectrometry
G01J 3/0229
Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows: using masks, aperture plates, spatial light modulators or…
G01J 3/0262
Details: constructional arrangements for removing stray light