CN117629405A - Spectrometer - Google Patents

Abstract

A spectrometer, comprising: an optical input member configured to receive and transmit a probe light, the probe light beam being introduced into a spectrometer; a specular reflection surface disposed parallel to an optical axis of the light incident member and spaced apart from the light incident member by a predetermined distance, and configured to specularly reflect a first light beam of the probe light output from the light incident member, the first light beam interfering with a second light beam of the probe light, wherein the second light beam is not reflected by the specular reflection surface; a lens module disposed on a traveling path of the first and second light beams and configured to converge the first and second light beams; and a detector, disposed at a side of the lens module away from the light incident component and the specular reflection surface, configured to receive interference light signals of the first light beam and the second light beam and generate an electrical signal.

Description

Spectrometer

Technical Field

The disclosure relates to the technical field of spectrometers, in particular to a spectrometer.

Background

The spectrometer is also called as a spectrometer, which is a device for measuring the intensities of different wavelength positions of a spectrum by using light detectors such as a photomultiplier tube, a CCD sensor and the like. It consists of an entrance slit, a dispersion system, an imaging system and an exit slit or sensor. The electromagnetic radiation of the radiation source is separated by a dispersive element into the desired wavelength or wavelength region and intensity measurements are made at selected wavelengths (or scanning a band of wavelengths). Conventional grating spectrometers typically require large area gratings, complex optical path designs, complex structures, and wavelength resolution subject to the structural dimensions of the instrument. The fourier transform spectrometer uses a different principle from the conventional grating spectrometer, and can realize measurement with high wavelength resolution, but because it needs to mechanically scan interference signals under different optical path differences, the measurement speed is slow.

Disclosure of Invention

The present disclosure provides a spectrometer comprising:

an optical input member configured to receive and transmit a probe light, the probe light beam being introduced into a spectrometer;

a specular reflection surface disposed parallel to an optical axis of the light incident member and spaced apart from the light incident member by a predetermined distance, and configured to specularly reflect a first light beam of the probe light output from the light incident member, the first light beam interfering with a second light beam of the probe light, wherein the second light beam is not reflected by the specular reflection surface;

a lens module disposed on a traveling path of the first and second light beams and configured to converge the first and second light beams; and

and the detector is arranged on one side of the lens module, which is far away from the light inlet component and the mirror reflection surface, and is configured to receive interference light signals of the first light beam and the second light beam and generate an electric signal.

In some embodiments, the lens module includes:

a first lens, a first optical axis of the first lens being parallel to the specular reflection surface, an entrance pupil surface of the first lens being spaced a first distance from the light entrance component;

the second lens is arranged on one side of the first lens far away from the light inlet component, a second optical axis of the second lens is coaxial with the first optical axis, and an exit pupil plane of the second lens is separated from the detector by a second distance.

In some embodiments, the detector comprises a photodetector that generates an electrical signal that satisfies the following equation with the spectral radiance of the probe light:

i (lambda) represents a light beam having a wavelength lambda in the probe lightSpectral radiance, I (x) denotes the electrical signal at the pixel at photodetector x, C denotes the instrument constant, h denotes the predetermined distance between the light-entering component and the specular reflecting surface, f ₂ Representing the second distance.

In some embodiments, the first lens comprises a first plano-convex lens with its convex surface facing the light-entering component; and

the second lens comprises a second plano-convex lens which is arranged on one side of the first plano-convex lens away from the light-entering component and is arranged in parallel with the first plano-convex lens, the convex surface of the second plano-convex lens faces away from the light-entering component,

the first focal length of the first plano-convex lens is equal to the first distance, the second focal length of the second plano-convex lens is equal to the second distance, and the first focal length is equal to the second focal length.

In some embodiments, the spectrometer further comprises:

and a linear polarizer disposed between the first lens and the second lens, configured to allow transmission of polarized light having a polarization direction parallel to the plane of the paper and perpendicular to the specular reflection surface, and to absorb polarized light having a polarization direction perpendicular to the plane of the paper.

In some embodiments, the spectrometer further comprises:

and a third lens disposed at an output end of the light-entering part and configured to reduce a divergence angle of the detection light output by the light-entering part.

In some embodiments, the output end of the light-in component is located at the ziming point of the third lens and is configured to reduce aberration of the detection light output by the light-in component.

In some embodiments, the third lens includes a hemispherical portion and a cylindrical portion, an end surface of the cylindrical portion remote from the hemispherical portion facing the output end of the light entrance member, the third lens satisfying the following relationship:

where d denotes the height of the cylindrical portion, r denotes the radius of the hemispherical portion, and n denotes the refractive index of the third lens.

In some embodiments, the first lens comprises a first plano-convex lens with its convex surface facing the light-entering component; and

the second lens comprises a second plano-convex lens which is arranged on one side of the first plano-convex lens away from the light-entering component and is arranged in parallel with the first plano-convex lens, the convex surface of the second plano-convex lens faces away from the light-entering component,

the first focal length of the first plano-convex lens is equal to the second distance, the second focal length of the second plano-convex lens is equal to the second distance,

the second distance and the first distance satisfy the following relationship:

wherein f ₁ Represents a first distance, f ₂ The second distance r denotes the radius of the hemispherical portion and n denotes the refractive index of the third lens.

In some embodiments, the light entry component comprises an optical fiber or a slit.

With respect to the related art, embodiments of the present disclosure have at least the following technical effects:

the spectrometer in the disclosure adopts the light inlet component to match with the specular reflection surface, so that part of the detection light output by the light inlet component is reflected by the specular reflection surface to form interference with the other part of the detection light, and is received and detected by the detection after being focused by the lens group. Compared with a grating spectrometer, the spectrometer in the present disclosure has high wavelength resolution under the limitation of the same volume; compared with a Fourier transform spectrometer, the spectrometer disclosed by the invention has the advantages of no moving parts, simple structure and high measurement speed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description, serve to explain the principles of the disclosure. It will be apparent to those of ordinary skill in the art that the drawings in the following description are merely examples of the disclosure and that other drawings may be derived from them without undue effort. In the drawings:

FIG. 1 is a schematic diagram of a spectrometer provided in some embodiments of the present disclosure;

FIG. 2 is a schematic diagram of the lens module of FIG. 1;

FIG. 3 is a schematic view of a spectrometer according to other embodiments of the present disclosure;

fig. 4 is a schematic structural view of the third lens shown in fig. 3.

Detailed Description

For a clearer description of the objects, technical solutions and advantages of the present disclosure, embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It will be apparent that the described embodiments are merely some, but not all embodiments of the present disclosure. Based on the embodiments in this disclosure, all other embodiments that a person of ordinary skill in the art would obtain without making any inventive effort are within the scope of protection of this disclosure. It is to be understood that the following description of the embodiments is intended to illustrate and explain the general concepts of the disclosure and should not be taken as limiting the disclosure. In the description and drawings, the same or similar reference numerals refer to the same or similar parts or components. For purposes of clarity, the drawings are not necessarily drawn to scale and some well-known components and structures may be omitted from the drawings.

Unless defined otherwise, technical or scientific terms used in this disclosure should be given the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The terms "first," "second," and the like, as used in this disclosure, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms "a" or "an" do not exclude a plurality. The word "comprising" or "comprises", and the like, means that elements or items preceding the word are included in the element or item listed after the word and equivalents thereof, but does not exclude other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", "top" or "bottom" and the like are used only to indicate a relative positional relationship, which may be changed accordingly when the absolute position of the object to be described is changed. When an element is referred to as being "on" or "under" another element, it can be "directly on" or "under" the other element or intervening elements may be present.

In the art, a conventional grating spectrometer generally needs a large-area grating and a complex optical path design, for example, a collimation system and a focusing system with complex structures, is complex in structure and difficult to manufacture, and generally has a moving component, is easy to damage and has poor reliability.

To overcome the above problems, the present disclosure provides a spectrometer including: an optical input member configured to receive and transmit a probe light, the probe light beam being introduced into a spectrometer; a specular reflection surface disposed parallel to the light incident member and spaced apart from the light incident member by a predetermined distance, configured to specularly reflect a first light beam of the detection light output from the light incident member, and interfere with a second light beam of the detection light of the first light beam, wherein the second light beam is not reflected by the specular reflection surface; a lens module disposed on a traveling path of the first and second light beams and configured to converge the first and second light beams; and a detector, disposed at a side of the lens module away from the light incident component and the specular reflection surface, configured to receive interference light signals of the first light beam and the second light beam and generate an electrical signal.

The spectrometer in the present disclosure adopts the light-entering component to match the specular reflection surface so that a part of the detection light output by the light-entering component is reflected by the specular reflection surface to form interference with another part of the detection light, and is received and detected by the detection after focusing by the lens group.

The spectrometer of the present disclosure is specifically described below.

Fig. 1 is a schematic structural diagram of a spectrometer according to some embodiments of the present disclosure, and fig. 1 is a schematic sectional diagram. As shown in fig. 1, some embodiments of the present disclosure provide a spectrometer 100, the spectrometer 100 including an light-entering component 10, a specular reflection surface 20, a lens module 30, and a detector 40.

The light-entering means 10 is configured to receive and transmit a probe light, the probe light is introduced into the spectrometer from outside the spectrometer, the probe light is emitted by an external light source, or the probe light is reflected by an external object, the probe light output by the light-entering means 10 is a slit light beam, in other embodiments, the probe light output by the light-entering means 10 may be a circular end surface of a single-mode fiber, which is constrained to be a slit light beam by a slit, and in other embodiments, the probe light output by the light-entering means 10 may be a spot light beam.

The specular reflection surface 20 is disposed parallel to the light incident component 10 and spaced apart from the light incident component 10 by a predetermined distance d, and the specular reflection surface 20 is configured to specularly reflect a first light beam L1 of the detection light output from the light incident component, and the first light beam L1 interferes with a second light beam L2 of the detection light, wherein the second light beam is not reflected by the specular reflection surface 20. The specular reflection surface 20 is, for example, a surface on which a metal reflection layer having a high reflectance is deposited, and has a very small surface roughness, and light incident on the specular reflection surface 20 is substantially specularly reflected without loss.

Since the first light beam L1 and the second light beam L2 are both derived from the probe light output from the light-entering unit 10 at the same time, the first light beam L1 and the second light beam L2 vibrate at the same frequency and in the same direction. After the first light beam L1 is reflected by the mirror reflection surface 20, its transmission path is substantially parallel to the transmission path of the second light beam L2, and the phase difference between the two is constant, so that the two meet the interference condition.

The first light flux L1 can be regarded as a light flux output from the light entrance member 10 with respect to the image of the specular reflection surface 20, and at this time, the light entrance member 10 and the image of the specular reflection surface 20 thereof can be regarded as forming double-slit interference.

In some embodiments of the present disclosure, the first light beam L1 and the second light beam L2 refer to any wavelength of the detected light, where the detected light may include multiple wavelengths of light, and for any wavelength of light, the light incident component 10 and the specular reflection surface 20 may be used to form interference.

The lens module 30 is disposed on a traveling path of the first light beam L1 and the second light beam L2, and configured to condense the first light beam L1 and the second light beam L2. The lens module 30 includes, for example, a lens or a lens group having a converging function such that interference fringes formed by interference of the first light beam L1 and the second light beam L2 are formed on a focal plane of the lens module 30, while interference fringes formed by interference of the first light beam L1 and the second light beam L2 are prevented from being formed in a distant place, resulting in an oversized spectrometer.

The detector 40 is disposed on a side of the lens module 30 away from the light entrance member 10 and the specular reflection surface 20, and is configured to receive the interference optical signals of the first light beam L1 and the second light beam L2 and generate an electrical signal. The detector 40 is, for example, a photodetector, whose light sensing surface receives the interference light signals of the first light beam L1 and the second light beam L2, that is, interference fringes, and the detector 40 converts the received interference light signals into electrical signals. Based on the electrical signal generated by the detector 40, the distribution of the light intensity of each wavelength in the detection light can be determined.

The spectrometer in the embodiment of the disclosure adopts the light inlet component to be matched with the specular reflection surface, so that one part of the detection light output by the light inlet component is interfered with the other part of the detection light after being reflected by the specular reflection surface, and is received and detected by the detection after being focused by the lens group.

In some embodiments, fig. 2 is a schematic structural diagram of the lens module in fig. 1. As shown in fig. 1 and 2, the lens module 30 includes a first lens 31 and a second lens 32. The first optical axis of the first lens 31 is parallel to the specular reflection surface 20, and the entrance pupil surface of the first lens is spaced apart from the light entrance member 10 by a first distance f ₁ . Specifically, the first lens 31 faces the light emitting direction of the light-in component 10, and the entrance pupil plane of the first lens is located at the output end of the light-in component 10Spaced a first distance f in a direction parallel to the specular reflection surface 20 ₁ 。

A second lens 32 is disposed on the side of the first lens 31 away from the light-entering component 10, the second optical axis of the second lens 32 is coaxial with the first optical axis of the first lens 31, and the exit pupil plane of the second lens 32 is spaced apart from the detector 40 by a second distance f ₂ . Specifically, the first lens 31 and the second lens 32 are arranged side by side with their optical axes coaxial, and the exit pupil plane of the second lens 32 is spaced apart from the photosurface of the detector 40 by a second distance f in a direction parallel to the specular reflection surface 20 ₂ 。

The lens module 30 composed of the first lens 31 and the second lens 32 forms interference fringes formed by interference of the first light beam L1 and the second light beam L2 on a focal plane of the lens module 30, and avoids interference fringes formed by interference of the first light beam L1 and the second light beam L2 from being formed in a distant place, resulting in an oversized spectrometer.

In some embodiments, the detector 40 includes a photodetector that generates an electrical signal that satisfies the following equation with the spectral radiance of the detection light:

i (lambda) represents the spectral radiance of the light beam with the wavelength lambda in the detection light, I (x) represents the electric signal on the pixel at the position of the photoelectric detector x, C represents the instrument constant, h represents the preset distance between the light inlet component and the specular reflection surface, and f ₂ Representing the second distance. Wherein the instrument constant C is related to an index of a particular optical device, such as the transmittance of the lens, the response of the detector, etc., and may be determined by a calibration procedure.

The intensity of the optical signal of the detection light at different positions of the sensor can be determined according to the electric signal generated by the detector 40, and then the spectral radiance of any wavelength beam can be obtained through the relation between the electric signal and the optical signal described in the above formula, that is, the distribution of each wavelength beam in the detection light can be determined.

In some embodiments, as shown in fig. 1 and 2, the first lens 31 includes a first plano-convex lens, hereinafter also referred to as a first plano-convex lens 31, and a convex surface of the first plano-convex lens 31 faces the light entrance member 10. The second lens 32 includes a second plano-convex lens, hereinafter also referred to as a second plano-convex lens 32, the second plano-convex lens 32 is disposed on a side of the first plano-convex lens 31 away from the light-incident member 10 and is disposed in parallel with the first plano-convex lens 31, and a convex surface of the second plano-convex lens 32 faces away from the light-incident member 10, i.e., a convex surface of the second plano-convex lens 32 faces the light-sensitive surface of the detector 40.

The first focal length of the first plano-convex lens 31 is equal to the first distance f ₁ The second focal length of the second plano-convex lens is equal to the second distance f ₂ And the first focal length is equal to the second focal length. At this time a first distance f ₁ From a second distance f ₂ Equal. For example, the first plano-convex lens 31 and the second plano-convex lens 32 are identical plano-convex lenses, and are disposed with their planes facing each other, as shown in fig. 2.

So designed, the output end of the light-entering component 10 is disposed on the focal plane of the first plano-convex lens 31, and the photosurface of the detector 40 is disposed on the focal plane of the first plano-convex lens 31. With this design, based on the mutual symmetry of the two plano-convex lenses, the aberration, particularly coma, of the imaging system constituted by the two lenses can be reduced

Specifically, in some embodiments, the first distance f ₁ For example 200mm, a second distance f ₂ For example, 200mm, and h is for example, 0.5mm, where the electrical signal generated by the photodetector and the spectral radiance of the detected light satisfy the following relationship:

where integration is the integration of all pixels of the detector, the instrument constant C is determined by scaling.

In some embodiments, as shown in fig. 1, the spectrometer 100 further includes a linear polarizer 50, where the linear polarizer 50 is disposed between the first lens 31 and the second lens 32, and configured to allow polarized light having a polarization direction parallel to the paper surface and perpendicular to the specular reflection surface to be transmitted, and absorb polarized light having a polarization direction perpendicular to the paper surface. That is, the linear polarizer 50 allows polarized light having a polarization direction parallel to the Y direction in the XY coordinate plane in fig. 1 to pass therethrough, and blocks and absorbs polarized light having a polarization direction perpendicular to the XY coordinate plane in fig. 1. After the polarized light in two polarization directions is reflected by the mirror reflection surface, a relative phase difference is generated, so that interference fringes finally formed by the two polarized light are not overlapped, and in order to avoid the phenomenon, only light in one polarization direction is allowed to pass through by the linear polaroid 50 to ensure accurate detection.

Fig. 3 is a schematic structural view of a spectrometer according to other embodiments of the present disclosure, and fig. 3 is a schematic sectional view. As shown in fig. 3, some embodiments of the present disclosure provide a spectrometer 100, the spectrometer 100 including a light-entering component 10, a specular reflection surface 20, a lens module 30, a detector 40, and a third lens 60.

The light-entering means 10 is configured to receive and transmit a probe light, the probe light is introduced into the spectrometer from outside the spectrometer, the probe light is emitted by an external light source, or the probe light is reflected by an external object, the probe light output by the light-entering means 10 is a slit light beam, in other embodiments, the probe light output by the light-entering means 10 may be a circular end surface of a single-mode fiber, which is constrained to be a slit light beam by a slit, and in other embodiments, the probe light output by the light-entering means 10 may be a spot light beam.

The specular reflection surface 20 is disposed parallel to the light incident component 10 and spaced apart from the light incident component 10 by a predetermined distance d, and the specular reflection surface 20 is configured to specularly reflect a first light beam L1 of the detection light output from the light incident component, and the first light beam L1 interferes with a second light beam L2 of the detection light, wherein the second light beam is not reflected by the specular reflection surface 20. The specular reflection surface 20 is, for example, a surface on which a metal reflection layer having a high reflectance is deposited, and has a very small surface roughness, and light incident on the specular reflection surface 20 is substantially specularly reflected without loss.

Since the first light beam L1 and the second light beam L2 are both derived from the probe light output from the light-entering unit 10 at the same time, the first light beam L1 and the second light beam L2 vibrate at the same frequency and in the same direction. After the first light beam L1 is reflected by the mirror reflection surface 20, its transmission path is substantially parallel to the transmission path of the second light beam L2, and the phase difference between the two is constant, so that the two meet the interference condition.

The first light flux L1 can be regarded as a light flux output from the light entrance member 10 with respect to the image of the specular reflection surface 20, and at this time, the light entrance member 10 and the image of the specular reflection surface 20 thereof can be regarded as forming double-slit interference.

In some embodiments of the present disclosure, the first light beam L1 and the second light beam L2 refer to any wavelength of the detected light, where the detected light may include multiple wavelengths of light, and for any wavelength of light, the light incident component 10 and the specular reflection surface 20 may be used to form interference.

As shown in fig. 3, the spectrometer 100 further includes a third lens 60, the third lens 60 being disposed at the output end of the light-entering part 10, configured to reduce the divergence angle of the detection light output by the light-entering part 10 without losing the light intensity. The third lens 60 is, for example, a converging lens, and can reduce the divergence angle of the output end of the light incident member 10 to 1/2 to 1/3 as it is.

The lens module 30 is disposed on a traveling path of the first light beam L1 and the second light beam L2, and configured to condense the first light beam L1 and the second light beam L2. The lens module 30 includes, for example, a lens or a lens group having a converging function such that interference fringes formed by interference of the first light beam L1 and the second light beam L2 are formed on a focal plane of the lens module 30, while interference fringes formed by interference of the first light beam L1 and the second light beam L2 are prevented from being formed in a distant place, resulting in an oversized spectrometer.

The detector 40 is disposed on a side of the lens module 30 away from the light entrance member 10 and the specular reflection surface 20, and is configured to receive the interference optical signals of the first light beam L1 and the second light beam L2 and generate an electrical signal. The detector 40 is, for example, a photodetector, whose light sensing surface receives the interference light signals of the first light beam L1 and the second light beam L2, that is, interference fringes, and the detector 40 converts the received interference light signals into electrical signals. Based on the electrical signal generated by the detector 40, the distribution of the light intensity of each wavelength in the detection light can be determined.

The spectrometer in the embodiment of the disclosure adopts the light inlet component to be matched with the specular reflection surface, so that one part of the detection light output by the light inlet component is interfered with the other part of the detection light after being reflected by the specular reflection surface, and is received and detected by the detection after being focused by the lens group.

In some embodiments, as shown in fig. 3, the output end 11 of the light-entering component 10 is located at the parceling point of the third lens 60, and is configured to reduce the aberration of the detection light output by the light-entering component 10.

Fig. 4 is a schematic structural view of the third lens shown in fig. 3, and as shown in fig. 4, the third lens 60 includes a hemispherical portion 61 and a cylindrical portion 62, and an end surface of the cylindrical portion 62 away from the hemispherical portion 61 faces the output end 11 of the light entrance member 10. The radius of the hemispherical portion 61 is the same as the radius of the cylindrical portion 62, both of which are of unitary construction. The arcuate surface of hemispherical portion 61 faces lens module 30.

The third lens 60 satisfies the following relationship:

where d denotes the height of the cylindrical portion, r denotes the radius of the hemispherical portion, and n denotes the refractive index of the third lens.

With this design, the output end 11 of the light entrance component 10 is located at the bright point of the third lens 60, so as to reduce the spherical aberration and coma aberration generated by the third lens.

In some embodiments, the lens module of fig. 3 also adopts the structure of the lens module of fig. 2. As shown in fig. 2 to 4, the lens module 30 includes a first lens 31 and a second lens 32. The first optical axis of the first lens 31 is parallel to the specular reflection surface 20, and the entrance pupil surface of the first lens is spaced apart from the light entrance member 10 by a first distance f ₁ . Specifically, the first lens 31 faces the light-emitting direction of the light-entering member 10, andthe entrance pupil plane of the first lens is spaced apart from the output end of the light-entering component 10 by a first distance f in a direction parallel to the specular reflection surface 20 ₁ 。

A second lens 32 is disposed on the side of the first lens 31 away from the light-entering component 10, the second optical axis of the second lens 32 is coaxial with the first optical axis of the first lens 31, and the exit pupil plane of the second lens 32 is spaced apart from the detector 40 by a second distance f ₂ . Specifically, the first lens 31 and the second lens 32 are arranged side by side with their optical axes coaxial, and the exit pupil plane of the second lens 32 is spaced apart from the photosurface of the detector 40 by a second distance f in a direction parallel to the specular reflection surface 20 ₂ 。

The lens module 30 composed of the first lens 31 and the second lens 32 forms interference fringes formed by interference of the first light beam L1 and the second light beam L2 on a focal plane of the lens module 30, and avoids interference fringes formed by interference of the first light beam L1 and the second light beam L2 from being formed in a distant place, resulting in an oversized spectrometer.

In some embodiments, as shown in fig. 2 to 4, the first lens 31 includes a first plano-convex lens, hereinafter also referred to as a first plano-convex lens 31, and a convex surface of the first plano-convex lens 31 faces the light entrance member 10. The second lens 32 includes a second plano-convex lens, hereinafter also referred to as a second plano-convex lens 32, the second plano-convex lens 32 is disposed on a side of the first plano-convex lens 31 away from the light-incident member 10 and is disposed in parallel with the first plano-convex lens 31, and a convex surface of the second plano-convex lens 32 faces away from the light-incident member 10, i.e., a convex surface of the second plano-convex lens 32 faces the light-sensitive surface of the detector 40.

The first focal length of the first plano-convex lens is equal to the second distance f ₂ The second focal length of the second plano-convex lens is equal to the second distance f ₂ The second and first distances satisfy the following relationship:

wherein f ₁ Representing the entrance of the first lensA first distance f between the pupil plane and the light entrance component ₂ The exit pupil plane of the second lens is spaced from the photosurface of the detector by a second distance in a direction parallel to the specular reflection surface, r represents the radius of the hemispherical portion, and n represents the refractive index of the third lens.

For example, the first plano-convex lens 31 and the second plano-convex lens 32 are identical plano-convex lenses, and are disposed with their planes facing each other, as shown in fig. 2. So designed, the virtual image generated by the output end of the light-entering component 10 passing through the third lens is arranged on the focal plane of the first plano-convex lens 31, and the photosurface of the detector 40 is arranged on the focal plane of the first plano-convex lens 31. With this design, based on the mutual symmetry of the two plano-convex lenses, it is possible to reduce aberration, particularly coma, of the imaging system constituted by the two lenses.

In some embodiments, the detector 40 includes a photodetector that generates an electrical signal that satisfies the following equation with the spectral radiance of the detection light:

i (lambda) represents the spectral radiance of the light beam with the wavelength lambda in the detection light, I (x) represents the electric signal on the pixel at the position of the photoelectric detector x, C represents the instrument constant, h represents the preset distance between the light inlet component and the specular reflection surface, and f ₂ Representing the second distance. Wherein the instrument constant C is related to an index of a particular optical device, such as the transmittance of the lens, the response of the detector, etc., and may be determined by a calibration procedure.

As described above, the structure of the embodiment shown in fig. 3 is similar to that of the embodiment shown in fig. 1, except that the third lens is added, compared to the embodiment shown in fig. 1, and the first distance f between the entrance pupil plane of the first lens and the light entrance component is further reduced while ensuring the detection effect ₁ So that the size of the spectrometer can be further limited.

In some embodiments, a standard light source of known spectral distribution, such as a blackbody light source of a certain temperature, may be used to illuminate the optical component 10, where I (lambda) is known, and the instrument constant C is determined by measuring the light intensity distribution on the detector, by the following formula.

In some embodiments, the light-entering component 10 includes an optical fiber or a slit, such as a single slit, and the detection light output by the light-entering component 10 is, for example, a slit of a light beam passing through the slit, such as perpendicular to the XY plane.

In summary, the spectrometer provided by the disclosure adopts the light incidence component to match the mirror reflection surface so that part of the detection light output by the light incidence component is interfered with the other part of the detection light after being reflected by the mirror reflection surface, and is received and detected by detection after being focused by the lens group.

Finally, it should be noted that: in the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. The system or the device disclosed in the embodiments are relatively simple in description, and the relevant points refer to the description of the method section because the system or the device corresponds to the method disclosed in the embodiments.

The above embodiments are merely for illustrating the technical solution of the present disclosure, and are not limiting thereof; although the present disclosure has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present disclosure.

Claims (10)

1. A spectrometer, comprising:

an optical input member configured to receive and transmit a probe light, the probe light beam being introduced into a spectrometer;

a specular reflection surface disposed parallel to an optical axis of the light incident member and spaced apart from the light incident member by a predetermined distance, and configured to specularly reflect a first light beam of the probe light output from the light incident member, the first light beam interfering with a second light beam of the probe light, wherein the second light beam is not reflected by the specular reflection surface;

a lens module disposed on a traveling path of the first and second light beams and configured to converge the first and second light beams; and

and the detector is arranged on one side of the lens module, which is far away from the light inlet component and the mirror reflection surface, and is configured to receive interference light signals of the first light beam and the second light beam and generate an electric signal.

2. The spectrometer of claim 1, wherein the lens module comprises:

a first lens, a first optical axis of the first lens being parallel to the specular reflection surface, an entrance pupil surface of the first lens being spaced a first distance from the light entrance component;

the second lens is arranged on one side of the first lens far away from the light inlet component, a second optical axis of the second lens is coaxial with the first optical axis, and an exit pupil plane of the second lens is separated from the detector by a second distance.

3. The spectrometer of claim 2, wherein the detector comprises a photodetector that generates an electrical signal that satisfies the following equation with the spectral radiance of the probe light:

i (lambda) represents the spectral radiance of the light beam with the wavelength lambda in the detection light, I (x) represents the electrical signal on the pixel at the photo detector x,c represents an instrument constant, h represents a predetermined distance between the light-entering member and the specular reflection surface, f ₂ Representing the second distance.

4. A spectrometer according to claim 2 or 3, wherein,

the first lens comprises a first plano-convex lens, and the convex surface of the first plano-convex lens faces the light inlet component; and

the second lens comprises a second plano-convex lens which is arranged on one side of the first plano-convex lens away from the light-entering component and is arranged in parallel with the first plano-convex lens, the convex surface of the second plano-convex lens faces away from the light-entering component,

the first focal length of the first plano-convex lens is equal to the first distance, the second focal length of the second plano-convex lens is equal to the second distance, and the first focal length is equal to the second focal length.

5. A spectrometer according to claim 2 or 3, wherein the spectrometer further comprises:

and a linear polarizer disposed between the first lens and the second lens, configured to allow transmission of polarized light having a polarization direction parallel to the plane of the paper and perpendicular to the specular reflection surface, and to absorb polarized light having a polarization direction perpendicular to the plane of the paper.

6. A spectrometer according to claim 2 or 3, wherein the spectrometer further comprises:

and a third lens disposed at an output end of the light-entering part and configured to reduce a divergence angle of the detection light output by the light-entering part.

7. The spectrometer of claim 6, wherein an output end of the light-in component is located at a zimine point of the third lens configured to reduce aberration of the detection light output by the light-in component.

8. The spectrometer of claim 6 or 7, wherein the third lens comprises a hemispherical portion and a cylindrical portion, an end face of the cylindrical portion remote from the hemispherical portion facing an output end of the light entry component, the third lens satisfying the following relationship:

where d denotes the height of the cylindrical portion, r denotes the radius of the hemispherical portion, and n denotes the refractive index of the third lens.

9. The spectrometer of claim 7, wherein the first lens comprises a first plano-convex lens having a convex surface facing the light entrance component; and

the second lens comprises a second plano-convex lens which is arranged on one side of the first plano-convex lens away from the light-entering component and is arranged in parallel with the first plano-convex lens, the convex surface of the second plano-convex lens faces away from the light-entering component,

the first focal length of the first plano-convex lens is equal to the second distance, the second focal length of the second plano-convex lens is equal to the second distance,

the second distance and the first distance satisfy the following relationship:

wherein f ₁ Represents a first distance, f ₂ The second distance r denotes the radius of the hemispherical portion and n denotes the refractive index of the third lens.

10. A spectrometer according to any of claims 1 to 3, wherein the light entry component comprises an optical fiber or slit.