CN113390854B

CN113390854B - High-density optical fiber bundle scattered light guide assembly

Info

Publication number: CN113390854B
Application number: CN202110938376.7A
Authority: CN
Inventors: 丁贤根; 汪小丹; 丁远彤
Original assignee: Harbour Star Health Biology Shenzhen Co ltd
Current assignee: Harbour Star Health Biology Shenzhen Co ltd
Priority date: 2021-08-16
Filing date: 2021-08-16
Publication date: 2022-01-25
Anticipated expiration: 2041-08-16
Also published as: CN113390854A

Abstract

The high-density optical fiber bundle scattered light guide assembly adopts an optical fiber bundle composed of a plurality of optical fibers, and comprises a planar window and a slit window, wherein the planar window collects scattered light flux as much as possible, the scattered light flux is grouped to form the slit window through an optical fiber bundle grouping method, and is directly transmitted to a subsequent spectrometer, the planar window is arranged into a regular hexagon below the optical fiber number (such as 61) with moderate number, the planar window is arranged into a circle or other shapes, the slit window is arranged into a single-row or multi-row vertical bar array, a slit required by the subsequent spectrometer is formed by a double CPC reflector or a cylindrical lens, or the slit window is directly generated by the vertical bar array under the condition that the diameter of a fiber core is combined with the slit required by the subsequent spectrometer. The invention can improve the collection efficiency of scattered light, improve the sensitivity of the spectrometer by 2 orders of magnitude, and can be used for the Raman spectrum detection of human bodies and the high-sensitivity detection of fluorescent scattered light and Rayli reflected light.

Description

High-density optical fiber bundle scattered light guide assembly

Technical Field

The invention relates to the technical field of optics and laser and the field of optical fiber elements, in particular to scattered light detection and a sensor, and particularly relates to a high-density optical fiber bundle scattered light guide assembly based on Raman spectrum detection, which is mainly used for improving detection sensitivity and reducing the intensity of exciting light in a spectrometer system so as to reduce the damage of the exciting light to living tissues.

Background

The optical fiber is used as an element for connecting the detection light and the optical splitter in the spectrometer system, and is one of essential key elements in the spectrometer, a single optical fiber is usually adopted in the prior art, and the spectrometer system is used for measuring the material property through light splitting, so that the principle and the variety are more. Among them, in the aspect of high-precision measurement, the spectrum detection based on fluorescence and based on raman effect is widely applied. According to the research findings of the inventor, the prior art of the optical fiber device is as follows:

optical fiber and absorption rate

Numerical aperture of optical fiber

Light incident on the end face of an optical fiber is not transmitted entirely by the optical fiber, but only light incident within a certain angle range. The sine of the angle α is called the numerical aperture (NA ═ sin α) of the optical fiber, and the range of the NA of the multimode optical fiber is generally between 0.18 and 0.23, so that sin α ═ α is generally available, i.e., the numerical aperture NA of the optical fiber is α. Sometimes, for convenience of expression, the numerical aperture is also expressed as follows: NA ═ nsin α, and n is the refractive index of the medium. The numerical apertures of optical fibers produced by different manufacturers are different.

Absorption of scattered light

According to the research of the inventor, the scattered light is radiated outwards by a 360-degree sphere from the point light source, and the absorptivity of the scattered light is defined as the percentage of the total energy of the light which is effectively absorbed and emitted by the sensor and is sensed by the point light source. For a scattered light detection system, the higher the overall absorbance, the better the detection performance of the system. In all the components of the whole channel, such as scattered light detection, transmission, photoelectric conversion, and the like, the total absorption rate is proportional to the product of the absorption rates of the respective components. The light guiding element combines both detection and transmission functions, and therefore its absorption is of utmost importance. The specific analysis is as follows:

for a single fiber:

based on the optical principle of optical fiber total reflection, the light entering the optical fiber port is required to have a normal incidence angle larger than the critical angle of the normal of the optical fiber, which is for hemispherical 180 × 360 omnidirectional scattered light, the energy of the scattered light outside the cone has no communication contribution as for the total reflection cone which really plays a communication role of the optical fiber. Therefore, the penalty for this situation needs to be calculated. Calculated as the critical angle of the normal plus or minus 13 degrees, the theoretical efficiency of absorption of a single optical fiber for scattered light is about 0.5% relative to plus or minus 90 degrees.

For a fiber bundle:

in far field optical calculation, the total absorption rate of the optical fiber bundle is approximately equal to the number of optical fibers in the optical fiber bundle multiplied by a single optical fiber, so that the more the number of optical fibers is, the higher the absorption rate is.

Most of the existing spectrometer systems adopt a single optical fiber to connect scattered light to a beam splitter, and in the measurement based on the fluorescence principle, because the intensity of fluorescence scattering is far greater than that of Raman scattering, the difference is greater than 3 orders of magnitude! Therefore, in the raman measurement based device, especially for the measurement of low concentration, the sensitivity of the single optical fiber is very deficient.

Two, a slit

The slit is one of the core components of the spectrometer. The slit window of the present invention is intended to make this function. The national mechanical industry administration publishes and implements the slit for spectrometer industry standard JB/T9331-1999 in 1 month 1/2000.

Specifically, the slit is a narrow and long slit hole with adjustable width. The slit has a fixed slit, an asymmetric slit with an adjustable single side and a symmetric slit with an adjustable double side. Each spectral line of the optical radiation after dispersion and splitting by the spectrometer is an image of the incident slit. The radiant energy entering or exiting the monochromator is regulated by the slit width. In modern spectrometers, the slit is automatically adjustable by rotational coupling of the grating. The slit width is in units of μm and the maximum width is 2 mm.

For a spectrometer based on the raman principle, the width of the slit is typically between 10 μm and 50 μm, the narrower the slit, the higher the resolution of the spectrometer. However, since the scattered light of the raman effect is extremely weak, the narrower the slit, the weaker the scattered light, and the longer the integration time required, the worse the signal-to-noise ratio in this case, in consideration of the sensitivity of the subsequent photoelectric sensor. Therefore, not only a slit of appropriate width but also more light flux absorption is required, and the solution is to increase the number of optical fibers in the optical fiber bundle.

Regarding the adjustment of the slit width, in practical applications, it is mostly used in the research process of specific products, and in practical products, a fixed width is usually used in order to simplify the design and reduce the complexity and cost thereof.

In the conventional Raman spectrum detection, the concentration of ultra-low concentration substances, such as human blood sugar, is very difficult to monitor, and the concentration is between 2.2mmol/L and 35 mmol/L.

Third, the optical filter

A filter is a lens that blocks light of a given frequency from passing through and passes light of other frequencies. The method specifically comprises the following steps:

1. and the low-pass filter prevents light rays with the frequency higher than the specified frequency from passing through, and allows light rays with the frequency lower than the specified frequency to pass through.

2. And the high-pass filter prevents light rays with the frequency less than the specified frequency from passing through and releases light rays with the frequency greater than the specified frequency from passing through.

3. And the band-pass filter is used for allowing light rays with the light ray frequency within a specified range to pass and preventing light rays with other frequencies from passing.

4. The band-stop filter prevents light rays with the light ray frequency within a specified range from passing through, and allows light rays with other frequencies to pass through.

5. The polarizer eliminates the glistening reflection formed by the light on the surface of the object.

In systems based on the raman principle, a low-pass filter is usually employed behind the slit of the optical path.

Sensitivity of Raman spectrometer

The existing Raman spectrometer can not realize the measurement for some special measurements, such as the in-vitro measurement of the blood sugar of a human body, because the sensitivity of the Raman spectrometer is seriously insufficient.

The method of the prior art is not sufficient

Based on the above analysis, the inventors believe that the prior art and methods suffer from the following disadvantages:

1. the scattered light absorption rate of a single optical fiber is only 0.5%, the sensitivity is seriously insufficient, and the monitoring of low-concentration substances cannot be realized.

2. The single optical fiber has a simple structure, and cannot realize the organization of the optical path, such as the formation of a slit.

3. Based on the recognition of the enhanced photoelectric conversion, the power of the excitation light source needs to be enhanced, which causes damage to human tissue.

Objects and purposes of the invention

The inventors have proposed a high-density optical fiber bundle scattering light guide assembly through long-term observation, experiment and study, and the object and intention of the present invention are:

1. by adopting the high-density optical fiber bundle, the absorption rate of scattered light is greatly improved, so that the sensitivity of a subsequent spectrometer is improved by 1-2 orders of magnitude.

2. By the grouping method for the optical fiber bundles, the scattered light can be effectively programmed, and the efficiency of the slit is improved.

3. The design of the integrated scattered light guide assembly is realized, the structure of the spectrometer is simplified, and the cost is reduced.

Advantageous effects of the invention

1. The absorption rate of scattered light and the measurement sensitivity of a subsequent spectrometer are greatly improved, and the estimated value can reach 1-2 orders of magnitude.

2. The absorption of the planar light spot and the conversion of the slit light spot are realized.

3. The effect of enhancing the sensitivity and the resolution is achieved by the grouping method of the optical fiber bundle.

4. The design of the integrated scattered light guide assembly is realized, the structure of the spectrometer is simplified, and the cost is reduced.

Disclosure of Invention

1. Description of the basic aspects

A high-density optical fiber bundle scattered light guide component comprises an optical fiber bundle, a planar window, a slit window and an optical fiber bundle grouping method, wherein:

the optical fiber bundle comprises an optical fiber bundle which is composed of more than one optical fibers and used for gathering and transmitting scattered light with specific wavelength.

In some embodiments, the fiber optic bundle is comprised of 7, 19, 37, 61, or even hundreds or thousands of fibers.

The planar window is formed by cutting a closed plane formed by arranging one end of an optical fiber bundle, comprises a circular, oval and polygonal section and is formed by fastening a planar window accessory.

In some embodiments, the planar window may be circular, square.

The slit window is formed by cutting the other end of the optical fiber bundle according to the vertical bar arrangement, is formed by fastening slit window accessories and is connected with a cylindrical lens or a reflector to form a slit.

The slit window is used for matching with a subsequent spectrometer, and if the core diameter of the optical fiber is small, for example, less than 100 μm, the optical fiber with closely arranged vertical bars can be directly used as the slit window. If the core diameter of the fiber is large, e.g., 100 μm or more, or if a narrow slit is required, then lens or mirror focusing is required.

The optical fiber bundle grouping method comprises an arrangement method of the position of each optical fiber in the optical fiber bundle from the planar window to the position in the slit window so as to be suitable for the application scene of the scattered light.

As a scattered light spectrometer device, the fiber bundle grouping herein mainly maps the position in the planar window to the position in the slit window, and specifically includes that the central point of the planar window (i.e. the focus of the condensed scattered light) corresponds to the central point of the slit window, and the strong scattered light point of the planar window corresponds to the central point of the slit window.

Scattered light enters the optical fiber bundles from the planar window, and is transmitted to the slit window to be output according to the optical fiber bundle grouping method.

In the invention, the light guide component is a high-density optical fiber bundle scattered light guide component with fixed mode, low cost and small volume, and can be classified as a sensor. The application objects are the detection of human blood sugar (such as CGM blood sugar measurement), hormone and special trace substances, and the detected substances are fixed and are not like general substance detection equipment to measure a plurality of substances.

For another design example, a focusing mode and a large light spot mode can be mixed and applied, the focusing mode provides high precision, the large light spot mode provides variation trend and measurement comfort, and the focusing mode is adopted to calibrate the large light spot mode, so that the device is particularly suitable for being used as human IVD (in vitro visual detection) equipment.

In applications similar to multispectral detection, additional embodiments may be devised in accordance with the present invention.

2. Description of the fiber bundle

On the basis of the technical scheme, the method comprises the following steps or the combination of the steps:

the optical fiber bundle comprises an optical fiber bundle which is composed of more than one optical fibers and used for gathering and transmitting scattered light with specific wavelength, wherein:

the specific wavelength includes an infrared wavelength, a near-infrared wavelength, a visible wavelength, an ultraviolet wavelength, or a designated wavelength.

For example, in some applications, specific excitation light wavelengths of 532nm, 785nm, 1063nm are selected.

The material, structure, size and numerical aperture of the optical fiber bundle meet the transmission requirement of the specific wavelength.

The convergent transmission scattered light comprises light rays with any incident angle which are emitted to the planar window, and can be converged and transmitted by the optical fiber bundle under the premise of conforming to the numerical aperture of the optical fiber bundle.

The optical fiber is made of glass, quartz or plastic.

3. Description of the fiber bundle

On the basis of the technical scheme, the method specifically comprises the following steps, points or a combination thereof:

the optical fibers in the optical fiber bundle further comprise different numbers, different materials, different structures, different sizes and different numerical apertures on the premise of conforming to the specific wavelength scattered light convergence transmission so as to form the optical fiber bundle with different characteristics, and the specific characteristics comprise:

the convergence rate of the optical fiber bundles is in direct proportion to the number of the optical fibers, when the number of the optical fibers is within 61, the optical fiber bundles are closely arranged at the planar window end according to a regular hexagon solid, and when the number of the optical fibers is more than 61, the optical fiber bundles are closely arranged according to a polygon or a round solid.

In the present invention, the number of optical fibers constituting the optical fiber bundle can be completely more, for example, hundreds or even thousands of optical fibers, and the optical fiber bundle can be used not only for narrow slit windows but also for matrix windows of imaging type.

In some embodiments, the planar window of the light guide assembly is installed in the receiving focal plane of the ellipsoid or the receiving focal plane of the compound parabolic reflector, and the shape and size of the planar window should be matched with the receiving focal plane to increase the convergence rate of the optical fiber bundle as much as possible.

The convergence rate of the optical fiber bundle is proportional to the square of the ratio of the inner core diameter of the optical fiber to the total diameter of the optical fiber, wherein the ratio of the inner core diameter of the optical fiber to the total diameter of the optical fiber is greater than 0.5.

The core diameter of an optical fiber is generally referred to as the core diameter, and the overall diameter of the optical fiber is the diameter including the core and the cladding, since one of the core features of the present invention is to increase the effective transmission rate (i.e., the rate of convergence or the rate of absorption) for scattered light, while only the core actually is capable of effectively transmitting scattered light, the smaller the thickness of the cladding, the better.

It is to be noted here that the choice of the core diameter requires reference to the wavelength of the scattered light, which is particularly important for single mode optical fibres.

The convergence rate of the optical fiber bundle is in direct proportion to the ratio of the total area of the inner cores in the optical fiber bundle to the total area of the optical fiber bundle, and the ratio of the total area of the inner cores in the optical fiber bundle to the total area of the optical fiber bundle is larger than 0.2.

The convergence rate of the fiber bundle is proportional to the total equivalent numerical aperture of the fiber bundle.

4. Description of planar window

the planar window is a cross section obtained by making a vertical section at the planar window of the optical fiber bundle and is used for receiving the scattered light.

And adopting the planar transparent material to cling to the tangent plane of the optical fiber bundle to form a protection window.

The protection window also comprises a transparent material, a lens and a filter lens which are arranged in a planar shape.

The planar window attachment further includes a mounting attachment for fixing the component, a protection tube for protecting the optical fiber bundle, and an adjusting attachment for adjusting displacement of the cross section on the optical axis.

The adjusting accessory comprises an adjusting screw rod, an adjusting screw and an indicating scale.

The adjustment attachment further comprises a stepper motor and control means to support electrical and manual adjustment of the displacement of the cross-section on the optical axis.

The size and standard of the planar window support the standard optical interface of the universal spectrometer, including but not limited to SMA905, GBIC, LC, SC, and other standards.

5. Description of slit Window

and the section of the optical fiber bundle, which is obtained by making a vertical section at the slit window, becomes a vertical slit, the scattered light is output, and a transparent material is adopted to be tightly attached to the section of the optical fiber bundle to form a protection window.

The slit window also comprises a cylindrical lens or a reflector which is connected and fastened by the slit window accessory, and a filter lens and a collimating mirror according to the application scene of the scattered light.

The width of the slit window can be manually adjusted or electrically adjusted within the range of 2 mu m-2 mm.

The size and standard of the slit window support the standard optical interface of the universal spectrometer, including but not limited to SMA905, GBIC, LC, SC, and other standards.

6. Description of the cylindrical lens

and adopting a condensing lens to condense and reduce the width of the slit under the condition that the diameter of the fiber core of the optical fiber is larger than the width of the slit.

The condensing lens comprises a single cylindrical lens which is used for focusing the light rays emitted by the vertical bar slit into strip-shaped light spots according to the vertical bar direction, wherein the width of each strip-shaped light spot is within the range of 2 mu m-2 mm, the length of each strip-shaped light spot is between 1 mm and 100 mm, and the focal length of each strip-shaped light spot is between 2mm and 100 mm.

The condensing lens further comprises a composite cylindrical lens, and the composite cylindrical lens condenses light to the central line vertical to the vertical bar along the direction of the vertical bar on the basis of the single cylindrical lens so as to control the length of the light spot of the vertical bar to be between 1 mm and 100 mm.

7. Description of the mirrors

under the condition that the diameter of the fiber core of the optical fiber is larger than the width of the slit, adopting a reflector to condense light to reduce the width of the slit;

the reflector comprises 2 curved reflectors which are arranged in parallel face to face, one end of each reflector is connected with the vertical strip slit, the other end of each reflector forms a slit with the width ranging from 2 mu m to 2mm, and the length of each slit ranges from 1 mm to 100 mm.

The curved surface mode of the curved surface reflector comprises a paraboloid, a spherical surface, a hyperboloid and a plane.

The curved surface reflector adopts a compound parabolic condenser mode, wherein the small side of a first compound parabolic reflector is connected with the small side of a second compound parabolic reflector, the large side of the first compound parabolic reflector is tightly connected with the section of the optical fiber of the slit window, after the light rays are emitted from the section, the light rays are converged by the first compound parabolic reflector, enter the small side of the second compound parabolic reflector, are reflected and converged by the second compound parabolic reflector again, and are output from the large side of the second compound parabolic reflector, so that the light rays emitted from the section of the optical fiber are narrowed and converged into light spots with reduced width.

8. Description of the method for organizing optical fiber bundles

the optical fiber bundle grouping method is a method for corresponding the position of each optical fiber in the optical fiber bundle in the planar window and the position in the slit window, and specifically includes:

the center-single layer grouping method comprises the steps that optical fibers in the slit window are closely arranged according to a single solid layer, a linear projection perpendicular to the planar window is established, the positions of all points in the linear projection and the positions of all points in the slit window are in corresponding relation, and the specific corresponding relation of each optical fiber is established by taking the center point of the planar window and the center point of the slit window as corresponding base points.

The spiral-single layer grouping method comprises the steps that optical fibers in the slit window are closely arranged according to a single-layer solid, an inside-out spiral line is established in the planar window by taking a central point as a starting point until all the optical fibers are traversed, and in the slit window, the optical fibers are numbered according to a singular sequence 1, 3, 5, 7 and … upwards by taking the central point as the starting point 1 and are numbered according to an even sequence 2, 4, 6 and the like downwards by taking an even sequence 2,

8.…, until all fibers are numbered, establishing specific relationships for each fiber in the order of fibers on the helix, corresponding to the numbering.

The center-multi-level grouping method includes closely arranging the optical fibers in the slit window in more than one solid layer, and the other steps establish the specific relationship of each optical fiber according to the center-single-level grouping method.

The spiral-multilayer grouping method includes closely packing the optical fibers in the slit window in more than one layer of solids, and the other steps establish the specific relationship of each optical fiber in the spiral-single layer grouping method.

The multi-layer imaging refers to that the arrangement of scattered light imaging is formed according to the fact that the arrangement position of optical fibers in the planar window corresponds to the arrangement position of optical fibers in the slit window one by one, the width of the slit window is increased at the moment, and the slit window is consistent with the shape of the planar window.

9. Description of optical elements

the width of the slit window can be manually adjusted or electrically adjusted within the range of 2 mu m-2 mm, and the slit window specifically comprises the following components:

the manual adjustment adopts the speculum mode 2 install the continuously adjustable part that constitutes by mechanical component on the curved surface speculum, adopt including the rotating member that screw rod, gear constitute, manual rotation the rotating member to change 2 the clearance of curved surface speculum in slit department.

The electric adjustment adopts the speculum mode 2 install the continuously adjustable part that constitutes by step motor and mechanical component on the curved surface speculum, step motor is controlled by control circuit, control circuit includes control signal input interface, receives outside control signal, accomplishes to the regulation of 2 curved surface speculums at the clearance of slit department.

The filter is a lens which prevents light rays in a specific wavelength range from passing through and allows light rays with other wavelengths to pass through, and comprises a low-pass filter, a band-pass filter and a high-pass filter.

The central wavelength of the excitation light used here is determined depending on the substance detected by raman spectroscopy or fluorescence spectroscopy, for example, 535nm, 785nm, 1064nm, and the like. Similarly, the selection of the low-pass filter, the high-pass filter and the band-stop filter is selected according to the central wavelength, which is particularly important in the detection based on the Raman scattering spectrum. A low-pass filter or a band-pass filter is typically selected to block the wavelength of the excitation light emitted by the light emitter.

10. Combination of

the outer part of the optical fiber bundle is packaged by a spring type solenoid sheath, and two ends of the optical fiber bundle are fixed with the planar window accessory and the slit window accessory so as to protect the optical fiber bundle.

The planar light spot of the optical fiber bundle is connected with a light-gathering cover, exciting light irradiates to a detection substance where a detection window is located, and the light-gathering cover gathers the exciting light generated by the detection substance to the planar window of the optical fiber bundle to generate an ellipsoidal light-gathering cover and a compound paraboloid light-gathering cover.

Drawings

FIG. 1: principle diagram of high-density optical fiber bundle scattered light guide assembly

FIG. 2: double CPC slit window structure diagram

FIG. 3: double CPC slit optical window path diagram

FIG. 4: structure of planar window

FIG. 5: structure of slit window of cylindrical lens

FIG. 6: double CPC connection light path diagram

FIG. 7: example of fiber bundle applications

The purpose and intention of the invention are realized by adopting the technical scheme of the following embodiment:

the first embodiment is as follows: light guide assembly of CPC high-power Raman spectrometer

One of the application embodiments of the high-efficiency scattered light condensing assembly is a high-power Raman spectrometer light guide assembly which is connected with a condenser and a spectrometer, so that the detection sensitivity of the system is greatly improved. Especially for the detection of ultra-low content substances and the trace detection of mixed substances, the sensitivity of the system can be improved by 1-3 orders of magnitude. Such as for human In Vitro Diagnostic products including but not limited to IVD (In Vitro Diagnostic products, abbreviated IVD, chinese) and other raman spectroscopy detection devices with high sensitivity. In the present embodiment, the method of the present invention is described only, and is not intended as a complete design of an actual system or as a limitation of the present invention.

1. Description of the drawings

FIG. 1: a schematic diagram of a high-density optical fiber bundle scattering light guide component.

The principle schematic diagram of the high-density optical fiber bundle scattering light guide assembly mainly comprises a planar window and a slit window. Here, 1001 denotes an optical fiber, and also denotes a cross section after cutting of the optical fiber in the planar window. 1002. 1003 is a protective sleeve for the bundle of optical fibers, which is made of a hard material at both ends of the bundle of optical fibers, i.e., near the planar window and the slit window, to complete the protection of the bundle of optical fibers, and between both ends of the bundle of optical fibers, a protective sleeve with a bending protection for the bundle of optical fibers, such as a spring sleeve and a soft plastic, is used for the protection. 1004 is a deformation protection sleeve at the joint slit window. It should be noted that the planar window and the slit window both include parameters required by the optical fiber interface designed as standard, and the standard at least includes SMA905, GBIC, etc. 1005 is a bracket of the slit window, and the optical fiber at the slit window is fixed by the bracket in a single row or in a multi-beat vertical bar shape. 1006 is the fiber at the slit window and its cut section. It should be noted that the cutting of the optical fiber at the planar window and the slit window includes vertical cutting, oblique cutting, round cutting and polishing.

FIG. 2: the double CPC slit window structure diagram.

This is one of the design schemes of the slit window in the present invention, i.e. the dual CPC docking mode is used. The scattered light emerging from the optical fiber of the slit window is collected to form a light image of the precise slit required by the spectrometer. Where 2001 is the core of the fiber, 2002 is the cladding of the fiber, 2003 is the cut section of the fiber at the slit window, 2004 and 2005 are two first CPC mirrors, respectively, that compress the light exiting the fiber section from the fiber diameter dimension to a dimension less than the fiber diameter in order to make the slit width narrower. 2007 and 2008 are two second CPC reflectors, respectively, which are used to collect the light from the first CPC, so that the exit angle is greatly reduced, and the light collection function is achieved. 2009 is where the slit is located. The CPC mount 2006 and the CPC mount 2010 are fasteners for attaching the slotted optical fiber.

FIG. 3: double CPC slit light window path schematic.

This is based on the optical path and working principle of the CPC. Wherein: 3001 is a slotted-window fiber bundle jacket, 3002 is the cladding of a vertical row of fibers, and 3003 is the core. 3004 and 3005 are each two first CPC mirrors that compress light exiting a cross-section of the fiber from a dimension of the fiber diameter to a dimension smaller than the fiber diameter in order to make the width of the slit narrower. 3006 and 3007 are two second CPC reflectors, respectively, which are used to collect the light from the first CPC, so that the emergent angle is greatly reduced to collect the light. 3008 the light emitted from the core reaches 3007 after reflection of 3004, and changes direction after reflection of 3007, thus showing convergence.

It should be noted that the double-CPC mirror is mounted end-to-end, and the first CPC compresses the width of the slit, so that the width of the light coming out of the tail of the first CPC is smaller than the diameter of the fiber core. The second CPC acts to focus and straighten the light at the entrance.

FIG. 4: planar window structure diagram.

This is the structure of the planar window of the present invention, in which the optical fibers in the optical fiber bundle are arranged in a regular polygon or a circle, and are bundled and fixed. 4001 is an optical fiber and cut section, 4002 is a sheath, 4003 is a protection made of transparent material, 4004 is a mounting fixture for a planar window, and 4005 is an adjuster for adjusting the axial movement of the cut section of the optical fiber bundle, the adjuster being intended to adjust the focal point or focal plane of the cut section of the optical fiber bundle to the focus of the focus when the planar window is mounted to the focus.

FIG. 5: cylindrical lens slit window structure diagram.

This is the second design scheme of the slit window in the present invention, i.e. the cylindrical lens slit pattern is used. Where 5001 and 5002 are vertical bars of aligned fibers in a slit window, 5001 is the core and 5002 is the cladding. 5003 is a cylindrical lens, which converges the light 5005 emitted from the plurality of vertically arranged optical fibers into a strip-shaped

light spot

5006, 5007 is a slit baffle, which is installed at the strip-shaped light spot formed by the cylindrical lens to strengthen the boundary of the slit. 5008 is a cross-sectional view of an optical fiber.

FIG. 6: double CPC connection light path diagram

This is an enlarged view of the junction of the front and back two-stage CPCs showing the details of the optical path. Wherein 6001 and 6002 are the upper and lower mirrors of the first-stage CPC, 6003 and 6004 are the upper and lower mirrors of the second-stage CPC, 6005 is the interface of the two-stage CPC, and PQ is the optical axis plane of the two-stage CPC. For example, the following steps are carried out: a ray 6006 reflects as 6007 via the CPC mirror at 6002, passes through the junction 6005, reflects as 6008 from the CPC mirror at 6003, and exits the second-stage CPC as a slit.

FIG. 7: example of fiber bundle applications

The invention is an application example in a Raman spectrometer or a fluorescence spectrometer, wherein a scattered light sensor uses laser as excitation light, a detected substance in a detection window is irradiated in an off-axis mode, generated scattered light is converged in a planar window of a light guide assembly of the invention, is transmitted to a slit window by an optical fiber bundle, is accessed to the spectrometer, is subjected to spectral analysis by the spectrometer, and is subjected to spectral analysis by a computer and software. The method comprises the following steps: 7001 is a detection window, 7002 is a scattered light sensor, 7003 is a planar window of an optical fiber bundle, 7004 is an optical fiber bundle, 7005 is a slit window of an optical fiber bundle, 7006 is a spectrometer or a spectrometer, 7007 is a display, 7008 is a computer, 7009 is an external power supply, and 7010 is a power supply converter.

2. Protocol and procedure

2.1: description of the basic aspects

In some embodiments, the planar window may be circular, square.

The optical fiber bundle grouping is mainly used for mapping the position in the planar window of the Fagaku to the position in the slit window, and specifically comprises that the central point (namely the focus of the converged scattered light) of the planar window corresponds to the central point of the slit window, and the strong scattered light point of the planar window corresponds to the central point close to the slit window.

2.2 bundle description of

The optical fiber is made of glass, quartz or plastic.

2.3 description of fiber bundle

In some embodiments, the planar window of the light guide assembly is mounted in the receiving focal plane of an ellipsoid or the receiving focal plane of a compound parabolic mirror, where the shape and size of the planar window is smaller than that of the receiving focal plane to increase the convergence rate of the fiber bundle as much as possible.

2.4 description of Flat Window

It is emphasized here that the shape of the cross-section needs to be matched to the shape and support of the receiving focal plane in order to increase the convergence rate of the fiber bundle as much as possible.

It is emphasized here that the transparent material is chosen to be suitable for the wavelength to be transmitted by the fiber bundle, and for infrared-polarized light, for example, quartz glass can be chosen. The lens may be a convex lens for focusing light, and indeed a reflective condenser may be used if the configuration permits. The filter may be a low pass filter, a band pass filter, a high pass filter. It is noted that in high precision spectrometers, the filter is preferably mounted behind the slit window, since the transmission of scattered light by the fiber will introduce wavelength distortions.

In fact, another function of the planar window attachment is to mount and secure the fiber bundle, which should be strong enough to support the cutting, positioning and securing of the fiber bundle.

The adjustment here includes adjusting the fiber bundle cross-section to be positioned at the receiving focal plane.

The control part of the stepping motor and the control part receives an external electric signal instruction or a manual signal, drives the stepping motor, the adjusting screw rod, the adjusting screw and the indicating scale, and completes the positioning of the section of the optical fiber bundle and the receiving focal plane.

The dimensions and standards of the facet window support standard optical interfaces of universal spectrometers including, but not limited to, SMA905, GBIC, LC, SC.

2.5 slit Window description

The dimensions and standards of the slit window support standard optical interfaces of universal spectrometers including, but not limited to, SMA905, GBIC, LC, SC.

It should be noted here that each optical fiber at the slit window comes from the optical fiber of the planar window of the optical fiber bundle, and the optical fiber bundle changes the planar light spot into the strip-shaped light spot at the slit by the constraint of the optical fiber. The optical fibers are arranged at the slit window depending on the diameter and number of optical fibers in the bundle. If the diameter of the fiber core of the optical fiber is enough to meet the requirements of a spectrometer system, the fiber core is directly cut to form a cross section, and the fiber core is encapsulated and protected by a transparent material without a subsequent cylindrical mirror or a reflector.

The arrangement of the optical fibers in the slit window can be single row or multiple rows.

As a general assembly, the size and standard of the planar window and the slit window support optical fiber interface standards including SMA905, GBIC, LC, SC and the like.

If the optical fiber is used as a special component and designed together with the subsequent straight mirror, the grating and the photoreceptor, the optical fiber is not limited by the standard of an optical fiber interface, and only the optical path of the slit, the straight mirror, the grating and the photoreceptor is considered to be reasonable.

2.6 cylindrical lens description

It should be noted here that if the core diameter of the optical fiber is larger than the required width of the slit, a single cylindrical mirror or a compound cylindrical mirror must be used to converge to the required width of the slit. Otherwise, the single cylindrical mirror or the compound cylindrical mirror may not be used.

2.7 description of the mirrors

As a typical example, the 2-piece curved reflector is a Compound Parabolic Concentrator (CPC), the CPC has a structure including a large side, a reflector and a small side, the width of the large side is greater than or equal to the width of the fiber core, the width of the small side is the width of the slit, the length of the small side is equal to the length of the slit window, and the inner surface can be plated with gold to increase the scattering light reflection efficiency.

2.8 description of fiber bundle grouping method

The spiral-single layer grouping method comprises the steps that optical fibers in the slit window are closely arranged according to a single layer solid, a spiral line from inside to outside is established in the planar window by taking a central point as a starting point until all the optical fibers are traversed, in the slit window, the central point is taken as the starting point 1, the optical fibers are numbered upwards according to a singular sequence of 1, 3, 5, 7 and … and are numbered downwards according to an even sequence of 2, 4, 6, 8 and … until all the optical fibers are numbered, and the specific corresponding relation of each optical fiber is established according to the optical fiber sequence on the spiral line and corresponding to the number.

Those skilled in the art will appreciate that the design concept of the present invention for fiber groupings can be based on secondary design to make the optical path more suitable for use in a scene.

It should be noted here that the grouping method may also group according to the type of the optical path in front of the planar window, and may also perform a targeted adjustment according to the subsequent size of the grating type and the parameter size of the photoelectric converter (such as CCD or CMOS), so as to optimize the receiving and converting efficiency.

2.9 description of optical elements

The electrical control also includes a telecommunications interface and an interface communication protocol.

The internal reflection cavity of the reflector is translated to the length of the slit window by adopting a multiple power path function, the internal reflection cavity is formed by processing a hard material, the left and the right sheets are symmetrically arranged, the width of a large side is designed to be larger than or equal to the width of an optical fiber core, the width of a small side is designed to be the width of the slit, the length of the small side is equal to the length of the slit window, and the internal surface can adopt a gold plating process so as to increase the scattered light reflection efficiency.

The multiple power function comprises a first-level parabolic function or a multi-level parabolic function with more than two levels.

The optical filter is a band-pass optical filter, which is particularly important in detection based on Raman scattering spectrum. The bandpass wavelengths are typically selected to be wavelengths suitable for raman scattered light spectral detection, such as 535nm, 785nm, 1064nm, and the like.

The low-pass filter, the high-pass filter and the band-stop filter are used, and are particularly important in detection based on Raman scattering spectrum. The low pass filter is typically selected to block the wavelength of the excitation light emitted by the light emitter, e.g., 535nm, 785nm, 1064nm, etc.

2.10, combinations

Depending on the application and the design of the optical light path, a person skilled in the art can carry out the relevant combinations according to the invention, according to the terms of the claims of the present invention. For example, the slit not only adopts a reflector of a CPC mode, but also can adopt a cylindrical lens as a simplified design, and if the fiber core diameter of the optical fiber is smaller, the slit design can be cancelled, and the optical fiber array in tree-shaped arrangement is directly adopted. Even with large diameter cores, it is possible to use mechanical slits directly without using cylindrical lenses and CPCs to focus light.

Example two: cylindrical mirror high power Raman spectrometer light guide assembly

1. Brief introduction to the drawings

This embodiment is a case of a design of the present invention that uses cylindrical lenses to form slit windows.

2. Description of the drawings

The slit window is shown in fig. 4.

3. Description of differentiation

The same points as the first embodiment are not described here, but the differences are: the slit window adopts a cylindrical lens structure as shown in fig. 4.

Example three: light guide assembly of fine high-power Raman spectrometer

This embodiment is an example of the present invention, which directly uses a thinner optical fiber, and the difference is that, as in the first embodiment, it is not described here: an optical fiber with a core diameter of 10 μm, which is already small enough, will here dispense with a CPC or cylindrical lens for focusing and will work directly as a slit window.

Claims

1. The high-density optical fiber bundle scattered light guide component comprises an optical fiber bundle, a planar window and a slit window, wherein the optical fiber bundle is grouped according to a grouping method, wherein:

the optical fiber bundle is an optical fiber bundle which is composed of more than one optical fibers and used for gathering and transmitting scattered light with specific wavelength;

the planar window is formed by arranging one end of an optical fiber bundle to form a closed plane, is formed by cutting, comprises a circular, oval and polygonal section and is formed by fastening a planar window accessory;

the slit window is formed by cutting the other end of the optical fiber bundle according to the vertical bar arrangement, is formed by fastening slit window accessories and is connected with the reflector to form a slit;

the reflector adopts a two-stage compound parabolic condenser mode, wherein the small side of a first compound parabolic reflector is connected with the small side of a second compound parabolic reflector, the large side of the first compound parabolic reflector is closely connected with the section of the optical fiber of the slit window, after being emitted from the section, light rays are converged by the first compound parabolic reflector, enter the small side of the second compound parabolic reflector, are reflected and converged by the second compound parabolic reflector again, and are output from the large side of the second compound parabolic reflector, so that the light rays emitted from the section of the optical fiber are narrowed and converged into light spots with reduced width;

the optical fiber bundle grouping method comprises an arrangement method of the position of each optical fiber in the optical fiber bundle from the planar window to the position in the slit window so as to be suitable for the application scene of the scattered light;

2. The high-density fiber-optic bundle dispersive light guide assembly according to claim 1, wherein:

the optical fiber bundle is an optical fiber bundle which is composed of more than one optical fibers and used for gathering and transmitting scattered light with specific wavelength, wherein:

the specific wavelength comprises an infrared wavelength or a near infrared wavelength or a visible light wavelength or an ultraviolet wavelength;

the material, structure, size and numerical aperture of the optical fiber bundle meet the transmission requirement of the specific wavelength;

the convergent transmission scattered light refers to light rays with any incident angle, which are emitted to the planar window, can be converged and transmitted by the optical fiber bundle on the premise of meeting the numerical aperture of the optical fiber bundle;

the optical fiber is made of glass, quartz or plastic.

3. The high-density fiber-optic bundle dispersive light guide assembly according to claim 2, wherein:

the convergence rate of the optical fiber bundles is in direct proportion to the number of the optical fibers, when the number of the optical fibers is within 61, the optical fiber bundles are closely arranged at the planar window end according to a regular hexagon solid, and when the number of the optical fibers is more than 61, the optical fiber bundles are closely arranged according to a polygon or a round solid;

the convergence rate of the optical fiber bundle is proportional to the square of the ratio of the inner core diameter of the optical fiber to the total diameter of the optical fiber, wherein the ratio of the inner core diameter of the optical fiber to the total diameter of the optical fiber is greater than 0.5;

the convergence rate of the optical fiber bundle is in direct proportion to the ratio of the total area of the inner cores in the optical fiber bundle to the total area of the optical fiber bundle, and the ratio of the total area of the inner cores in the optical fiber bundle to the total area of the optical fiber bundle is more than 0.2;

4. The high-density fiber-optic bundle dispersive light guide assembly according to claim 1, wherein:

the planar window is a cross section obtained by making a vertical section on the planar window of the optical fiber bundle and is used for receiving the scattered light;

forming a protection window on the section of the optical fiber bundle;

the protection window also comprises a mounting surface-shaped transparent material or a lens or a filter lens;

the planar window accessory also comprises a mounting accessory for fixing the component, a protection tube for protecting the optical fiber bundle and an adjusting accessory for adjusting the displacement of the section on the optical axis;

the adjusting accessory comprises an adjusting screw rod, an adjusting screw and an indicating scale;

the adjustment accessory further comprises a stepper motor and a control component to support electrical and manual adjustment of the displacement of the cross section on the optical axis;

the size and standard of the facet window support the standard optical interface of the universal spectrometer, including SMA905 or GBIC or LC or SC, and the filter is a lens which prevents the light rays in a specific wavelength range from passing through and allows the light rays in other wavelengths to pass through, and includes a low-pass filter or a band-pass filter or a high-pass filter.

5. The high-density fiber-optic bundle dispersive light guide assembly according to claim 1, wherein:

the section of the optical fiber bundle, which is obtained by making a vertical section at the slit window, becomes a vertical slit, the scattered light is output, and a transparent material is adopted to be tightly attached to the section of the optical fiber bundle to form a protection window;

the slit window also comprises a reflector which is connected and fastened by the slit window accessory, and a filter lens and a collimating mirror according to the application scene of the scattered light;

the width of the slit formed by the slit window can be manually adjusted or electrically adjusted within the range of 2 mu m-2 mm;

the size and standard of the slit window support the standard optical interface of a universal spectrometer, including SMA905 or GBIC or LC or SC, and the filter is a lens which prevents light rays in a specific wavelength range from passing through and allows light rays in other wavelengths to pass through, and includes a low-pass filter, a band-pass filter and a high-pass filter.

6. The high-density fiber-optic bundle dispersive light guide assembly according to claim 5,

7. The high-density optical fiber bundle scattering light guide assembly as claimed in claim 1, wherein the optical fiber bundle grouping method is a corresponding method for the position of each of the optical fibers in the optical fiber bundle in the facet window and the slit window, and specifically comprises:

the center-single layer grouping method comprises the steps that optical fibers in the slit window are closely arranged according to a single solid layer, a linear projection perpendicular to the planar window is established, the positions of all points in the linear projection are in corresponding relation with the positions of all points in the slit window, and the specific corresponding relation of each optical fiber is established by taking the center point of the planar window and the center point of the slit window as corresponding base points; or the like, or, alternatively,

the spiral-single layer grouping method comprises the steps that optical fibers in a slit window are tightly arranged according to single-layer solids, a spiral line from inside to outside is established in a planar window by taking a central point as a starting point until all the optical fibers are traversed, in the slit window, the central point is taken as the starting point 1, the optical fibers are numbered upwards according to a singular sequence of 1, 3, 5, 7 and … and are numbered downwards according to an even sequence of 2, 4, 6, 8 and … until all the optical fibers are numbered, and the specific corresponding relation of each optical fiber is established according to the sequence of the optical fibers on the spiral line and corresponding to the number; or the like, or, alternatively,

the center-multilayer grouping method comprises the steps that optical fibers in the slit window are closely arranged according to more than one layer of solid, and the other steps are used for establishing the specific corresponding relation of each optical fiber according to the center-single-layer grouping method; or the like, or, alternatively,

the spiral-multilayer grouping method comprises closely arranging the optical fibers in more than one layer of solid in the slit window, and establishing the specific corresponding relation of each optical fiber according to the spiral-single-layer grouping method; or the like, or, alternatively,

8. The high-density fiber bundle dispersive light guide assembly according to claim 6, wherein:

the slit width formed by the slit window can be manually adjusted or electrically adjusted within the range of 2 mu m-2 mm, and the method specifically comprises the following steps:

the manual adjustment is to adopt the reflectors, install a continuously adjustable component consisting of mechanical components on 2 curved reflectors, adopt a rotating part consisting of a screw and a gear, and manually rotate the rotating part so as to change the gaps of the 2 curved reflectors at the slits;

the electric adjustment adopts the speculum 2 install the continuously adjustable part that constitutes by step motor and mechanical component on the curved surface speculum, step motor is controlled by control circuit, control circuit includes control signal input interface, receives outside control signal, accomplishes right the regulation of 2 curved surface speculums at the clearance of slit department.

9. The high-density optical fiber bundle scattering light guide member according to any one of claims 1 to 8, characterized in that:

10. The high-density optical fiber bundle scattering light guide member according to any one of claims 1 to 8, characterized in that:

the planar window of the optical fiber bundle is connected with a light-gathering cover, exciting light irradiates to a detection substance where the detection window is located, the light-gathering cover gathers the exciting light generated by the detection substance to the planar window of the optical fiber bundle, and the light-gathering cover comprises an ellipsoidal light-gathering cover and a compound parabolic light-gathering cover.