A device for connecting optical fiber bundle and spectrometer

Abstract

The present invention discloses a connection device for an optical fiber bundle and a spectrometer, and relates to the field of spectral technology. The key points of the technical solution are: comprising a connector and a collimation system arranged in the connector and used to convert the light emitted by the optical fiber bundle into parallel light, wherein a light propagation channel is provided in the connector, and the two ends of the connector located at the light propagation channel are respectively set as an optical fiber bundle connection end and a spectrometer connection end, the optical fiber bundle connection end is connected to the optical fiber bundle output end, the spectrometer connection end is connected to the incident end of the spectrometer, and the collimation system is arranged on the light propagation channel between the spectrometer connection end and the optical fiber bundle output end. The present invention can facilitate the spectrometer to receive the light of the optical fiber bundle, and there is no need to strictly align the spectrometer with the optical fiber bundle, and there is no need to strictly process the incident slit of the spectrometer, which has the effect of improving the convenience of operation and use.

Description

Technical Field

[0001] The present invention relates to the field of spectrum technology, and more specifically, to a connecting device for an optical fiber bundle and a spectrometer. Background Art

[0002] Spectroscopy is a technique for measuring the intensity of light in the ultraviolet, visible, near infrared, infrared and other wavelengths. Spectral measurement has a wide range of applications, such as color measurement, concentration measurement of chemical components, electromagnetic radiation analysis, light source luminescence and aerospace spectral analysis.

[0003] Spectrometer is also called spectrometer, and the most widely known one is direct reading spectrometer. It is a device that measures the intensity of different wavelength positions of spectral lines with photodetectors such as photomultiplier tubes. It consists of an entrance slit, a dispersion system, an imaging system and one or more exit slits. The electromagnetic radiation of the radiation source is separated into the required wavelength or wavelength region by the dispersion element, and the intensity is measured at the selected wavelength (or scanning a certain band).

[0004] In the prior art, when the optical fiber bundle emits light to the spectrometer, since the spectrometer is an incident slit, the light emitted by the optical fiber bundle needs to be aligned before it can enter the incident slit of the spectrometer. The common arrangement of the optical fiber bundle output end is pseudo-straight or circular. When the optical fiber bundle output end is arranged in a straight line, the operator needs to strictly align it with the incident slit of the spectrometer. This technology is difficult and the operation process needs to be constantly adjusted, which is very troublesome. If the optical fiber bundle output end is arranged in a circular shape, the center of the optical fiber bundle end face needs to strictly coincide with the center of the slit. This technology is limited by the processing technology of the slit, which is more difficult and more troublesome to operate. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a connecting device between an optical fiber bundle and a spectrometer, which can facilitate the spectrometer to receive the light of the optical fiber bundle, does not require strict alignment of the spectrometer and the optical fiber bundle, and does not require strict processing of the spectrometer's incident slit, thereby having the effect of improving the convenience of operation and use.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A device for connecting an optical fiber bundle and a spectrometer, comprising a connector and a collimation system arranged in the connector and used to convert light emitted by the optical fiber bundle into parallel light, wherein a light propagation channel is opened through the connector, and the connector is located at two ends of the light propagation channel, which are respectively set as an optical fiber bundle connection end and a spectrometer connection end, the optical fiber bundle connection end is connected to the optical fiber bundle output end, the spectrometer connection end is connected to the incident end of the spectrometer, and the collimation system is arranged on the light propagation channel between the spectrometer connection end and the optical fiber bundle output end.

[0008] It is further configured that the field of view angle 2ω of the collimation system is set to 23.0° to 26.6°, the numerical aperture of the optical fiber is set to 0.20 to 0.23, and the total length l≤10.6 mm.

[0009] Further configuration: the field of view angle 2ω of the collimation system is set to 25.4°, and the numerical aperture of the optical fiber is set to 0.22.

[0010] Further configuration: the collimation system includes a first lens, a second lens and a third lens sequentially arranged from the spectrometer connection end to the optical fiber bundle connection end, the second lens is set as a negative optical focal length lens, and the first lens and the third lens are both set as positive optical focal length lenses.

[0011] It is further arranged that the focal length f1 of the first lens, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy the focal length f of the collimating system:

[0012] 1.50<|f1 / f|<1.70, 14.55<|f2 / f|<14.75, 1.90<|f3 / f|<2.10.

[0013] It is further configured that: the surface with a curvature radius r1 of the first lens is a convex surface, and the surface with a curvature radius r2 is a concave surface; the surface with a curvature radius r2 of the second lens is a convex surface, and the surface with a curvature radius r3 is a concave surface or a near-flat surface; the surface with a curvature radius r4 of the third lens is a convex surface, and the surface with a curvature radius r5 is a concave surface.

[0014] It is further configured that: the first lens and the second lens are bonded to form a doublet lens, the r2 surface of the second lens and the r2 surface of the first lens are bonding surfaces, and the two bonding surfaces are both spherical surfaces, and the radii of the two spherical surfaces are equal.

[0015] Further settings: The parameters of the collimation system are as follows:

[0016] 12.6<r1<12.8, 1.15<d1<1.25, 1.82<n1<1.88, 40.5<v1<41.5.

[0017] 10.5<r2<10.9, 1.15<d2<1.25, 1.88<n2<1.93, 20.7<v2<21.6.

[0018] 78.0<r3<78.2, 0.95<d3<1.15.

[0019] 4.5<r4<4.9, 1.15<d4<1.25, 1.78<n3<1.82, 44.9<v3<46.5,

[0020] 6.3<r5<6.5, 5.85<d5<6.10;

[0021] In the formula: r1, r2, r3, r4, r5 are the curvature radii of the corresponding surface number 1 to surface number 5, d1 is the center distance between surface number 1 and surface number 2, d2 is the center distance between surface number 2 and surface number 3, d3 is the center distance between surface number 3 and surface number 4, d4 is the center distance between surface number 4 and surface number 5, d5 is the center distance between surface number 5 and the focus, n1 and v1 are the refractive index and Abbe number of the glass material used for the first lens, n2 and v2 are the refractive index and Abbe number of the glass material used for the second lens, and n3 and v3 are the refractive index and Abbe number of the glass material used for the third lens.

[0022] Further configuration: the spectrometer connection end is provided with a docking joint 1 with internal threads, the docking joint 1 is threadedly connected to the incident end of the spectrometer, and the optical fiber bundle connection end is provided with a docking joint 2 with external threads, the docking joint 2 is threadedly connected to the optical fiber bundle.

[0023] It is further configured that the connector and the light propagation channel are both cylindrical, and a fixing ring for fixing the lens of the collimation system is provided in the light propagation channel.

[0024] By adopting the above technical solution, the present invention has the following advantages compared with the prior art:

[0025] 1. The two ends of the connector are connected to the optical fiber bundle and the spectrometer respectively, so that the light emitted by the optical fiber bundle passes through the light propagation channel and is collimated by the collimation system to form evenly distributed parallel light, so that it is easy to be evenly received by the spectrometer, and it is convenient for the spectrometer to receive the light of the optical fiber bundle. There is no need to strictly align or strictly process the spectrometer and the optical fiber bundle, which has the effect of improving the convenience of operation;

[0026] 2. The field of view angle 2ω is set to 25.4° and the numerical aperture of the optical fiber is set to 0.22, which can match the optical fiber with the collimation system and improve the light coupling efficiency of the optical fiber bundle; by improving the collimation of the collimation system, the uniformity of the light after collimation and parallelization is improved, so that the spectrometer can receive light uniformly and the convenience of operation is improved;

[0027] 3. By using the second lens of the negative power lens and the first lens of the positive power lens and the third lens, it is convenient to convert the light of the optical fiber bundle into parallel light, so that the spectrometer can evenly receive the light and improve the convenience of operation;

[0028] 4. By bonding the first lens and the second lens into a double cemented lens, spherical aberration, coma and axial chromatic aberration can be corrected to achieve higher wavelength resolution, which is beneficial for spectrometer reception;

[0029] 5. By adopting the threaded connection method, it is convenient to disassemble and assemble the spectrometer connection end and the optical fiber bundle connection end on the spectrometer and the optical fiber bundle, thereby improving the convenience of operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the structure of the cutaway connection device between the optical fiber bundle and the spectrometer;

[0031] Figure 2 Schematic diagram of light propagation in the collimation system.

[0032] In the figure: 1. connector; 11. light propagation channel; 12. optical fiber bundle connection end; 121. docking connector 2; 13. spectrometer connection end; 131. docking connector 1; 2. collimation system; 21. first lens; 22. second lens; 23. third lens; 3. fixing ring. DETAILED DESCRIPTION

[0033] Reference Figure 1 to Figure 2 The connection device between the optical fiber bundle and the spectrometer is further described.

[0034] A device for connecting an optical fiber bundle to a spectrometer, such as Figure 1 As shown, it includes a connector 1 and a collimation system 2 arranged in the connector 1. The collimation system 2 is used to convert the light emitted by the optical fiber bundle into parallel light so as to be uniformly absorbed by the spectrometer.

[0035] like Figure 1 and Figure 2 As shown, a light propagation channel 11 is provided through the connector 1, and both the connector 1 and the light propagation channel 11 are set to be cylindrical, so as to ensure that when the connector 1 rotates, the extension route of the internal light propagation channel 11 is not affected. The connector 1 is provided with a fiber bundle connection end 12 and a spectrometer connection end 13 at both ends of the light propagation channel 11, respectively. The fiber bundle connection end 12 is connected to the output end of the fiber bundle, and the spectrometer connection end 13 is connected to the incident end of the spectrometer. The collimation system 2 is provided on the light propagation channel 11 between the spectrometer connection end 13 and the output end of the fiber bundle, so that the light emitted by the fiber bundle is formed into parallel light by the collimation system 2, and then output to the spectrometer by the spectrometer connection end 13, so that it is evenly received by the spectrometer, which facilitates the light of the fiber bundle to enter the spectrometer and improves the convenience of operation.

[0036] like Figure 1 As shown, a fixing ring 3 for fixing the lens of the collimation system 2 is provided at a position of the light propagation channel 11 near the spectrometer connection end 13, so as to facilitate the installation of the collimation system 2 and make the collimation system 2 close to the spectrometer connection end 13 to reduce the distance of the light emitted into the spectrometer, so as to facilitate the spectrometer to evenly receive the light.

[0037] like Figure 1As shown, further, the spectrometer connection end 13 is provided with a docking joint 131 with an internal thread, and the docking joint 131 is threadedly connected to the incident end of the spectrometer, and the optical fiber bundle connection end 12 is provided with a docking joint 121 with an external thread, and the docking joint 121 is threadedly connected to the optical fiber bundle, so as to facilitate the installation of the connector 1 between the optical fiber bundle and the spectrometer, so as to facilitate the use of the connecting device to dock the optical fiber bundle and the spectrometer, facilitate the uniform reception of light by the spectrometer, and facilitate the disassembly and assembly of the connector 1 to improve the convenience of operation and use.

[0038] like Figure 1 and Figure 2 As shown, specifically, the collimation system 2 includes a first lens 21, a second lens 22 and a third lens 23 which are sequentially arranged from the spectrometer connection end 13 to the optical fiber bundle connection end 12. The second lens 22 is set as a negative optical focal lens, and the first lens 21 and the third lens 23 are both set as positive optical focal lenses, so as to convert the light into parallel light for emission. Among them, the curvature radius r1 surface of the first lens 21 is convex, and the curvature radius r2 surface is concave, the curvature radius r2 surface of the second lens 22 is convex, and the curvature radius r3 surface is concave or nearly flat, and the curvature radius r4 surface of the third lens 23 is convex, and the curvature radius r5 surface is concave. The focal length f1 of the first lens 21, the focal length f2 of the second lens 22 and the focal length f3 of the third lens 23 satisfy the focal length f of the collimation system 2:

[0039] 1.50<|f1 / f|<1.70, 14.55<|f2 / f|<14.75, 1.90<|f3 / f|<2.10

[0040] The light emitted from the optical fiber bundle is refracted by the first lens 22, the second lens 23 and the third lens 24 to form evenly distributed parallel light, which is convenient for the spectrometer to receive evenly.

[0041] Furthermore, the first lens 21 and the second lens 22 are bonded to form a double lens, and the r2 surface of the second lens 22 and the r2 surface of the first lens 21 are bonded surfaces, and the two bonded surfaces are both set to be spherical surfaces, and the radii of the two spherical surfaces are equal. The first lens 21 and the second lens 22 use different types of optical glass to correct spherical aberration, coma and axial chromatic aberration, etc., so that the wavelength resolution is higher, which is conducive to uniform reception of the spectrometer.

[0042] like Figure 1 As shown, the field angle 2ω of the collimation system 2 is set to 23.0° to 26.6°, the numerical aperture of the optical fiber is set to 0.20 to 0.23, the total length l≤10.6 mm, and the parameters of the collimation system 2 are as follows:

[0043] 12.6<r1<12.8, 1.15<d1<1.25, 1.82<n1<1.88, 40.5<v1<41.5.

[0044] 10.5<r2<10.9, 1.15<d2<1.25, 1.88<n2<1.93, 20.7<v2<21.6.

[0045] 78.0<r3<78.2, 0.95<d3<1.15.

[0046] 4.5<r4<4.9, 1.15<d4<1.25, 1.78<n3<1.82, 44.9<v3<46.5,

[0047] 6.3<r5<6.5, 5.85<d5<6.10

[0048] In the formula: r1, r2, r3, r4, r5 are the curvature radii of the corresponding surface number 1 to surface number 5, d1 is the center distance between surface number 1 and surface number 2, d2 is the center distance between surface number 2 and surface number 3, d3 is the center distance between surface number 3 and surface number 4, d4 is the center distance between surface number 4 and surface number 5, d5 is the center distance between surface number 5 and the focus, n1 and v1 are the refractive index and Abbe number of the glass material used for the first lens 21, n2 and v2 are the refractive index and Abbe number of the glass material used for the second lens 22, and n3 and v3 are the refractive index and Abbe number of the glass material used for the third lens 23.

[0049] By selecting the above parameters, the light can be evenly diverged into parallel light after passing through the collimation system 2, so as to improve the light collimation effect and facilitate the spectrometer to evenly receive the light.

[0050] Working principle: by connecting the optical fiber bundle to the second docking connector 121 and the spectrometer to the first docking connector 131, the optical fiber bundle connection end 12 and the spectrometer connection end 13 are respectively docked to the optical fiber bundle and the spectrometer, so that the light emitted by the optical fiber bundle enters the light propagation channel 11, and after being collimated by the collimation system 2, uniformly distributed parallel light is emitted, which is uniformly received by the spectrometer, so that the light emitted by the optical fiber bundle is uniformly received by the spectrometer, and there is no need to calibrate the optical fiber bundle and the spectrometer, and the center of the end face of the optical fiber bundle does not have to coincide with the center of the incident slit of the spectrometer, which facilitates the assembly of the optical fiber bundle and the spectrometer, and has the effect of improving the convenience of operation.

[0051] The following is an example of lens parameters of the collimation system provided in the embodiment of the present invention.

[0052] Embodiment 1: The field angle 2ω of the collimation system 2 is set to 25.4°, the numerical aperture of the optical fiber is set to 0.22, and the optical transfer function MTF value of the collimation system 2 is greater than 0.5 at 60 lp / mm.

[0053] The data of the curvature radius r, center thickness d, refractive index n, and Abbe constant v of each lens are shown in Table 1:

[0054] Table 1

[0055] Face number Radius of curvature r Thickness d Refractive index n Abbe number v 1 12.7085 1.23 1.86 41.01 2 10.8302 1.23 1.92 21.51 3 78.0880 1.10 4 4.7870 1.23 1.80 46.20 5 6.4416 6.05

[0056] It should be noted that the face numbers in Table 1 are Figure 2 In the schematic diagram of the collimation system structure shown, the lens surface numbers from left to right.

[0057] By reasonably selecting the surface shapes and parameter values ​​of the first lens 21, the second lens 22 and the third lens 23, the collimation system can disperse the light incident from the optical fiber bundle through the third lens 23, and then disperse it into uniformly distributed parallel light after refraction by the second lens 22 and the first lens 21, thereby improving the collimation effect of the collimation system 2 so as to facilitate uniform absorption by the spectrometer.

[0058] Embodiment 2: The difference between this embodiment and embodiment 1 is that the field angle 2ω of the collimation system 2 is set to 23.0°, the optical fiber numerical aperture is set to 0.18, and the optical transfer function MTF value of the collimation system 2 is greater than 0.55 at 60lp / mm.

[0059] The data of the curvature radius r, center thickness d, refractive index n, and Abbe constant v of each lens are shown in Table 2:

[0060] Table 2

[0061]

[0062]

[0063] It should be noted that the face numbers in Table 2 are Figure 2 In the schematic diagram of the collimation system structure shown, the lens surface numbers from left to right.

[0064] By selecting the above parameters, the collimation system can disperse the light incident from the optical fiber bundle through the third lens 23, and then disperse it into uniformly distributed parallel light after refraction by the second lens 22 and the first lens 21, thereby improving the collimation effect of the collimation system 2 so as to facilitate uniform absorption by the spectrometer.

[0065] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A device for connecting an optical fiber bundle to a spectrometer, characterized in that: The invention comprises a connector (1) and a collimation system (2) arranged in the connector (1) and used for converting light emitted by an optical fiber bundle into parallel light, wherein the collimation system (2) comprises a first lens (21), a second lens (22) and a third lens (23) arranged in sequence from a spectrometer connection end (13) to an optical fiber bundle connection end (12), wherein the second lens (22) is a negative optical power lens, and the first lens (21) and the third lens (23) are both positive optical power lenses; a light propagation channel (11) is provided through the connector (1), and the connector (1) is provided with an optical fiber bundle connection end (12) and a spectrometer connection end (13) at two ends of the light propagation channel (11), respectively; the optical fiber bundle connection end (12) is connected to an optical fiber bundle output end, and the spectrometer connection end (13) is connected to an incident end of a spectrometer, and the collimation system (2) is provided on the light propagation channel (11) between the spectrometer connection end (13) and the optical fiber bundle output end.

2. The device for connecting an optical fiber bundle to a spectrometer according to claim 1, characterized in that: The field angle 2ω of the collimation system (2) is set to 23.0° to 26.6°, the numerical aperture of the optical fiber is set to 0.20 to 0.23, and the total length l is ≤10.6 mm.

3. The device for connecting an optical fiber bundle to a spectrometer according to claim 2, characterized in that: The field angle 2ω of the collimation system (2) is set to 25.4°, and the numerical aperture of the optical fiber is set to 0.

22.

4. The device for connecting an optical fiber bundle to a spectrometer according to claim 1, characterized in that: The focal length f1 of the first lens (21), the focal length f2 of the second lens (22), and the focal length f3 of the third lens (23) satisfy the following relationship with the focal length f of the collimating system (2): 1.50<|f1 / f|<1.70, 14.55<|f2 / f|<14.75, 1.90<|f3 / f|<2.

10.

5. The device for connecting an optical fiber bundle to a spectrometer according to claim 1, characterized in that: The surface with a curvature radius r1 of the first lens (21) is a convex surface, and the surface with a curvature radius r2 is a concave surface; the surface with a curvature radius r2 of the second lens (22) is a convex surface, and the surface with a curvature radius r3 is a concave surface or a near-flat surface; the surface with a curvature radius r4 of the third lens (23) is a convex surface, and the surface with a curvature radius r5 is a concave surface.

6. The device for connecting an optical fiber bundle to a spectrometer according to claim 5, characterized in that: The first lens (21) and the second lens (22) are bonded to form a doublet lens, the r2 surface of the second lens (22) and the r2 surface of the first lens (21) are bonded surfaces, and both of the two bonded surfaces are set as spherical surfaces, and the radii of the two spherical surfaces are equal.

7. The device for connecting an optical fiber bundle to a spectrometer according to claim 5, characterized in that: The parameters of the collimation system (2) are as follows: 12.6<r1<12.8, 1.15<d1<1.25, 1.82<n1<1.88, 40.5<v1<41.5; 10.5<r2<10.9, 1.15<d2<1.25, 1.88<n2<1.93, 20.7<v2<21.6; 78.0＜r3＜78.2，0.95＜d3＜1.15； 4.5<r4<4.9, 1.15<d4<1.25, 1.78<n3<1.82, 44.9<v3<46.5, 6.3＜r5＜6.5，5.85＜d5＜6.10； Wherein: r1, r2, r3, r4, r5 are the curvature radii of the corresponding surface number 1 to surface number 5, d1 is the center distance between surface number 1 and surface number 2, d2 is the center distance between surface number 2 and surface number 3, d3 is the center distance between surface number 3 and surface number 4, d4 is the center distance between surface number 4 and surface number 5, d5 is the center distance between surface number 5 and the focus, n1 and v1 are the refractive index and Abbe number of the glass material used for the first lens (21), n2 and v2 are the refractive index and Abbe number of the glass material used for the second lens (22), and n3 and v3 are the refractive index and Abbe number of the glass material used for the third lens (23).

8. A device for connecting an optical fiber bundle to a spectrometer according to any one of claims 1 to 7, characterized in that: The spectrometer connection end (13) is provided with a first butt joint (131) having an internal thread, and the first butt joint (131) is threadedly connected to the incident end of the spectrometer. The optical fiber bundle connection end (12) is provided with a second butt joint (121) having an external thread, and the second butt joint (121) is threadedly connected to the optical fiber bundle.

9. The device for connecting an optical fiber bundle to a spectrometer according to claim 1, characterized in that: The connector (1) and the light propagation channel (11) are both cylindrical, and a fixing ring (3) for fixing the lens of the collimation system (2) is provided in the light propagation channel (11).

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