US 2025/0085164 A1 · WAVELENGTH CALIBRATION METHOD FOR GRATING SPECTROMETERS

Abstract

A wavelength calibration method for a grating spectrometer is provided, including: moving a plurality of characteristic peaks of a calibration light source to a central position of a detector of the spectrometer respectively, and determining a functional relationship between a grating rotation angle of the rotatable grating and a central wavelength; and determining parameters γ, f, a, b, c in the following physical model, the physical model being used to calculate a corresponding wavelength at each pixel within an imaging range of the detector when the central wavelength is determined, λ ′ = sin ⁢ ( Ψ - γ 2 ) + sin ⁢ ( Ψ + γ 2 + arctan ⁢ ( a ⁡ ( n ⁢ x ) 2 + b ⁡ ( n ⁢ x ) + c f ) ) 1 ⁢ 0 - 6 · m · N wherein Ψ is the grating rotation angle corresponding to the central wavelength as determined via the functional relationship, γ is built-in angle of the spectrometer, f is a focal distance of the spectrometer, m is grating diffraction order, N is the number of grating rulings (unit: line/mm), nx is a distance between a corresponding pixel and a central pixel.

Claims20

Dependent claims

A wavelength calibration method for a spectrometer, the spectrometer comprising a rotatable grating, the method comprising:

by rotating the rotatable grating, moving a plurality of characteristic peaks of a calibration light source to a central position of a detector of the spectrometer respectively, and determining a functional relationship between a grating rotation angle of the rotatable grating and a central wavelength;
and
by analyzing a plurality of spectrograms obtained under a plurality of central wavelengths, determining parameters γ, f, a, b, c in the following physical model, the physical model being used to calculate a corresponding wavelength at each pixel within an imaging range of the detector when the central wavelength is determined,
λ
′
=
sin
⁢
(
Ψ
-
γ
2
)
+
sin
⁢
(
Ψ
+
γ
2
+
arctan
⁢
(
a
⁡
(
n
⁢
x
)
2
+
b
⁡
(
n
⁢
x
)
+
c
f
)
)
1
⁢
0
-
6
·
m
·
N
wherein, Ψ is the grating rotation angle corresponding to the central wavelength as determined via the functional relationship, γ is a built-in angle of the spectrometer, f is a focal distance of the spectrometer, m is a grating diffraction order, N is the number of grating rulings (unit:
line/mm), nx is a distance between a corresponding pixel and a central pixel, and a, b, c are distance optimization parameters.

55 more elements

An apparatus for wavelength calibration of a spectrometer, comprising:

a storage, configured to store computer programs;
and
a processor, coupled to the storage, when the computer programs are executed by the processor, the processor being configured to execute the method comprising:
by rotating the rotatable grating, moving a plurality of characteristic peaks of a calibration light source to a central position of a detector of the spectrometer respectively, and determining a functional relationship between a grating rotation angle of the rotatable grating and a central wavelength;
and
by analyzing a plurality of spectrograms obtained under a plurality of central wavelengths, determining parameters γ, f, a, b, c in the following physical model, the physical model being used to calculate a corresponding wavelength at each pixel within an imaging range of the detector when the central wavelength is determined,
λ
′
=
sin
⁢
(
Ψ
-
γ
2
)
+
sin
⁢
(
Ψ
+
γ
2
+
arctan
⁡
(
a
⁡
(
n
⁢
x
)
2
+
b
⁡
(
n
⁢
x
)
+
c
f
)
)
1
⁢
0
-
6
·
m
·
N
wherein, Ψ is the grating rotation angle corresponding to the central wavelength as determined via the functional relationship, γ is a built-in angle of the spectrometer, f is a focal distance of the spectrometer, m is a grating diffraction order, N is the number of grating rulings (unit:
line/mm), nx is a distance between a corresponding pixel and a central pixel, and a, b, c are distance optimization parameters.

58 more elements

A computer readable storage medium, on which a program code is stored, when the program code is executed by a processor, enabling the processor to execute the method comprising:

by rotating the rotatable grating, moving a plurality of characteristic peaks of a calibration light source to a central position of a detector of the spectrometer respectively, and determining a functional relationship between a grating rotation angle of the rotatable grating and a central wavelength;
and
by analyzing a plurality of spectrograms obtained under a plurality of central wavelengths, determining parameters γ, f, a, b, c in the following physical model, the physical model being used to calculate a corresponding wavelength at each pixel within an imaging range of the detector when the central wavelength is determined,
λ
′
=
sin
⁢
(
Ψ
-
γ
2
)
+
sin
⁢
(
Ψ
+
γ
2
+
arctan
⁡
(
a
⁡
(
n
⁢
x
)
2
+
b
⁡
(
n
⁢
x
)
+
c
f
)
)
1
⁢
0
-
6
·
m
·
N
wherein, Ψ is the grating rotation angle corresponding to the central wavelength as determined via the functional relationship, γ is a built-in angle of the spectrometer, f is a focal distance of the spectrometer, m is a grating diffraction order, N is the number of grating rulings (unit:
line/mm), nx is a distance between a corresponding pixel and a central pixel, and a, b, c are distance optimization parameters.

55 more elements

Dependencies are inferred from the claim text.

Wavelength calibration method for grating spectrometers

Life of this patent

Wavelength calibration method for grating spectrometers

Life of this patent

Abstract

Claims20