A micro-region adjustable optical path model for an angle-resolved spectroscopy system

Abstract

The utility model relates to the field of spectral detection technology especially, and more particularly to a kind of micro-region adjustable light path model for angle-resolved optical spectrum system.It solves the optical model of traditional angle-resolved optical spectrum measurement system There is significant performance contradiction, i.e.the angle measurement range of traditional optical model and micro area excitation are incompatible.The utility model increases multiple adjusting mechanism in light path model, and aperture diaphragm is increased between objective and double cemented lens, to limit the influence of mechanical installation error on spot size, and excitation spot is compressed to 20 microns level, and the adjustment of diaphragm position is realized simultaneously through two-dimensional adjusting frame.Long working distance objective is simultaneously matched, to provide the basis on physical size for wide range angle measurement, through excitation end unit and collection end unit are completely symmetrical except exclusive element, the fiber diameter of first optical fiber is 50 microns, the fiber diameter of second optical fiber is 1000 microns, achromatic double cemented lens, to realize the directional excitation of light path.

Description

Technical Field

[0001] This invention relates to the field of spectral detection technology, and in particular to a micro-region adjustable optical path model for an angle-resolved spectral system. Background Technology

[0002] In SPs-related research, it is typically necessary to irradiate the metal-medium interface with light waves to achieve effective excitation of surface plasmons. Different surface plasmon structures have different resonance wavelengths and resonance angles, exhibiting strong directional characteristics during measurement (requiring directional excitation and collection). Different resonance wavelengths correspond to different resonance angles; therefore, to explore applications under different resonance conditions, spectral instruments with angle resolution are required for measurement.

[0003] Currently, common optical models for angle-resolved spectroscopy measurement systems mainly fall into two categories: those mounted on macroscopic rotating arms and those based on the back focal plane imaging principle of microscopes. Both have their own drawbacks. Optical systems mounted on macroscopic rotating arms can measure larger angles but produce larger output spots; systems based on the back focal plane imaging principle of microscopes produce micrometer-sized output spots but have a smaller measurement angle range. These two types of optical models exhibit significant performance contradictions: traditional optical models either possess large-angle measurement capabilities but cannot achieve micro-area excitation, or they can achieve micrometer-sized micro-area measurements but have limited angular coverage.

[0004] Therefore, there is an urgent need for a micro-region adjustable optical path model for angle-resolved spectral systems that can be directly mounted on a macroscopic rotating arm system, has a large measurement angle range, and allows the output spot diameter of the optical path model to reach the micrometer level, enabling micro-region angle-resolved measurements. Utility Model Content

[0005] Therefore, to address the aforementioned problems, this invention proposes a micro-region adjustable optical path model for angle-resolved spectroscopy systems. This model resolves the significant performance contradictions inherent in traditional angle-resolved spectroscopy measurement systems, which either possess large-angle range measurement capabilities but cannot achieve micro-region excitation, or can achieve micrometer-level micro-region measurement but have limited angular coverage.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: it includes an excitation end unit and a collection end unit, wherein the optical paths of the excitation end unit and the collection end unit have a convergence point;

[0007] The excitation end unit sequentially includes a light source device, a first optical fiber for light transmission, a first optical fiber collimator connected to the light source device via the first optical fiber, a polarizer for converting light into a specific polarization state to excite surface plasmons, a first cemented doublet lens for numerical aperture matching and focusing the light output from the first optical fiber collimator onto the imaging surface of the objective lens, a first objective lens for focusing the light spot projected onto its imaging surface by the first cemented doublet lens onto the sample surface at a single magnification to achieve spot micro-regioning, and an aperture stop disposed between the first cemented doublet lens and the first objective lens.

[0008] The collection unit includes, in sequence, a spectrometer, a second optical fiber, a second optical fiber collimator connected to the spectrometer via an optical fiber, a second cemented doublet lens, and a second objective lens for collecting light emitted from the sample.

[0009] The collecting end unit and the excitation end unit are symmetrically distributed, and except for the polarizer, aperture and light source device installed in the excitation end unit, and the spectrometer connected to the collecting end unit, the other optical elements of the excitation end unit and the collecting end unit are completely identical.

[0010] Furthermore, the light source device includes a 250W bulb, which is a 250W spherical high-pressure, short-arc xenon lamp.

[0011] Furthermore, both the excitation end unit and the collection end unit are provided with adjustment mechanisms, which include a five-dimensional adjustment frame for adjusting the position of the fiber collimator and a four-dimensional adjustment frame for adjusting the position of the cemented doublet lens.

[0012] Furthermore, the five-dimensional adjustment frame is equipped with an optical fiber collimator adapter, and the first optical fiber collimator and the second optical fiber collimator are respectively fixed through the corresponding optical fiber collimator adapter; the four-dimensional adjustment frame is equipped with a cemented doublet lens mounting adapter ring, and the first cemented doublet lens and the second cemented doublet lens are respectively fixed through the corresponding cemented doublet lens mounting adapter ring.

[0013] Furthermore, the excitation end unit is also provided with a two-dimensional adjustment frame, which is located between the four-dimensional adjustment frame and the objective lens, and between the first cemented doublet lens and the aperture; the aperture is fixedly installed on the bearing surface of the two-dimensional adjustment frame, and the two-dimensional adjustment frame can drive the aperture to translate and adjust along the X-axis and Y-axis directions in a plane perpendicular to the optical axis of the optical path.

[0014] Furthermore, the aperture of the aperture is 20 micrometers.

[0015] Furthermore, the excitation end unit also includes a rotating mirror frame, which is disposed between the five-dimensional adjustment frame and the four-dimensional adjustment frame, and is located between the first fiber collimator and the polarizer.

[0016] The polarizer is fixedly mounted on the bearing surface of the rotating frame. The rotating frame can drive the polarizer to rotate around the optical axis of the optical path to adjust the polarization angle.

[0017] Furthermore, both the first and second optical fibers are made of quartz multimode fiber and the cladding is made of fluorine-doped quartz material. The diameter of the first optical fiber is 50 micrometers and the diameter of the second optical fiber is 1000 micrometers. The numerical aperture of the first optical fiber is 0.12 and the numerical aperture of the second optical fiber is 0.22.

[0018] Furthermore, both the first cemented doublet and the second cemented doublet are achromatic cemented doublets.

[0019] Furthermore, the achromatic cemented doublet has a diameter of 10mm and a focal length of 20mm, and the wavelength range of the achromatic cemented doublet is 400-1000nm.

[0020] Furthermore, both the first and second objectives are long working distance objectives.

[0021] By adopting the aforementioned technical solution, the beneficial effects of this utility model are:

[0022] This invention adds multiple adjustment mechanisms to the optical path model and an aperture stop between the objective lens and the cemented doublet lens to limit the influence of mechanical installation errors on the spot size and compress the excitation spot to the 20-micrometer level.

[0023] Simultaneously, the long working distance objective lens provides a physical dimensional basis for wide-range angular measurements. Furthermore, by ensuring complete symmetry between the excitation and collection units (excluding dedicated components), and by using a 50-micrometer diameter first fiber, a 1000-micrometer diameter second fiber, and an achromatic cemented doublet lens, the influence of component differences and wavelength deviations on the light spot quality is avoided. Through the arrangement of various optical components and adjustment mechanisms, the light spot diameter output by this optical path model reaches the micrometer level, enabling micro-area angular resolution measurements. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a micro-region adjustable optical path model for an angle-resolved spectral system according to the present invention;

[0025] Figure 2 This is an enlarged schematic diagram of the structure of the excitation end unit and the collection end unit of this utility model;

[0026] Figure 3 This is a schematic diagram of the optical transmission structure of a micro-region adjustable optical path model for an angle-resolved spectral system according to the present invention.

[0027] In the figure: Excitation end unit-1, Collection end unit-2, Light source device-10, First optical fiber-11, First optical fiber collimator-12, Polarizer-13, First cemented doublet lens-14, First objective lens-15, Aperture stop-16, Spectrometer-17, Second optical fiber-20, Second optical fiber collimator-21, Second cemented doublet lens-22, Second objective lens-23, Five-dimensional adjustment frame-3, Four-dimensional adjustment frame-4, Fiber collimator adapter-5, Cemented doublet lens mounting adapter ring-6, Two-dimensional adjustment frame-7, Rotating mirror frame-8. Detailed Implementation

[0028] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0029] refer to Figures 1-3 This embodiment provides a micro-region adjustable optical path model for an angle-resolved spectroscopy system. Its structure includes an excitation unit 1 and a collection unit 2, and the optical paths of the excitation unit 1 and the collection unit 2 have a convergence point.

[0030] The excitation end unit 1 includes, in sequence, a light source device 10, a first optical fiber 11 for light transmission, a first optical fiber collimator 12 connected to the light source device 10 through the first optical fiber 11, a polarizer 13 for converting light into a specific polarization state to excite surface plasmons, a first cemented doublet lens 14 for numerical aperture matching and focusing the light output from the first optical fiber collimator 12 onto the imaging surface of the objective lens, a first objective lens 15 for focusing the light spot projected by the first cemented doublet lens 14 onto the sample surface at a single magnification to achieve spot micro-regioning, and an aperture 16 disposed between the first cemented doublet lens 14 and the first objective lens 15.

[0031] The collection unit 2 includes, in sequence, a spectrometer 17, a second optical fiber 20, a second optical fiber collimator 21 connected to the spectrometer 17 via an optical fiber, a second cemented doublet lens 22, and a second objective lens 23 for collecting the light emitted by the sample.

[0032] The collecting end unit 2 and the excitation end unit 1 are symmetrically distributed, and except for the polarizer 13, aperture 16 and light source device 10 installed in the excitation end unit 1, and the spectrometer 17 connected to the collecting end unit 2, the other optical elements of the excitation end unit 1 and the collecting end unit 2 are completely identical.

[0033] This optical path model mainly uses the symmetrical distribution of the collection end unit 2 and the excitation end unit 1, with their optical paths converging at a point that ultimately falls on the sample surface. This ensures that the "excitation light action area" and the "collection light acquisition area" completely overlap, avoiding the problem of low light signal collection efficiency caused by misalignment of the excitation and collection areas. With the above optical element setup, the output light spot diameter reaches the micrometer level, enabling micro-area angular resolution measurement.

[0034] When using

[0035] Specifically, during the installation of optical instruments, even a 0.1mm deviation can significantly impact the final optical path performance. To mitigate the effects of mechanical installation errors, this optical path model is further improved by incorporating adjustment mechanisms in both the excitation unit 1 and the collection unit 2. These mechanisms include a five-dimensional adjustment frame 3 for adjusting the position of the fiber collimator and a four-dimensional adjustment frame 4 for adjusting the position of the cemented doublet lens. The excitation unit 1 also includes a two-dimensional adjustment frame 7, positioned between the four-dimensional adjustment frame 4 and the objective lens, and between the first cemented doublet lens 14 and the aperture 16. The aperture 16 is fixedly mounted on the support surface of the two-dimensional adjustment frame 7, which can drive the aperture 16 to translate along the X and Y axes in a plane perpendicular to the optical axis of the path. The addition of the aperture 16, with an aperture diameter of 20 micrometers, between the objective lens and the cemented doublet lens, helps to limit the size of the light spot.

[0036] Meanwhile, the five-dimensional adjustment frame 3 is equipped with fiber optic collimator adapters 5, and the first fiber optic collimator 12 and the second fiber optic collimator 21 are fixed through their respective fiber optic collimator adapters 5. The five-dimensional adjustment frame 3 can perform "full-dimensional fine-tuning" of the position and angle of the fiber optic collimator, calibrating the optical axis direction of the light emitted by the fiber optic collimator to ensure complete alignment with the optical axis of the subsequent polarizer and cemented doublet lens, avoiding spot shift or energy loss caused by optical axis misalignment. The four-dimensional adjustment frame 4 is equipped with cemented doublet lens mounting adapter rings 6, and the first cemented doublet lens 14 and the second cemented doublet lens 22 are fixed through their respective cemented doublet lens mounting adapter rings 6.

[0037] Since SPR excitation requires converting light into a specific polarization state, this application incorporates a polarizer 13 into the excitation unit 1 to convert light into specific polarized light, preparing for effective excitation of surface plasmons. Specifically, the excitation unit 1 also includes a rotating mirror frame 8, which is positioned between the five-dimensional adjustment frame 3 and the four-dimensional adjustment frame, and between the first fiber collimator 12 and the polarizer 13. The polarizer 13 is fixedly mounted on the bearing surface of the rotating mirror frame 8. The rotating mirror frame 8 can drive the polarizer 13 to rotate around the optical axis of the optical path to adjust the polarization angle, specifically enabling 360° rotation adjustment of the polarizer 13.

[0038] The first optical fiber 11 has a diameter of 50 micrometers. This 50-micrometer diameter reduces the initial diameter of the incident light spot. Furthermore, to improve the coupling efficiency between the optical fiber and the device, enhance optical transmission stability, and reduce optical signal fluctuations, the second optical fiber 20 has a diameter of 1000 micrometers. Both the first optical fiber 11 and the second optical fiber 20 are made of quartz multimode fiber with a fluorine-doped quartz cladding. The numerical aperture of the first optical fiber 11 is 0.12, and the numerical aperture of the second optical fiber 20 is 0.22. The fiber optic interface of the first optical fiber 11 is SMA905-SMA905, and the fiber optic interface of the second optical fiber 20 is SMA905-FC / APC.

[0039] Furthermore, both the first cemented doublet 14 and the second cemented doublet 22 are achromatic cemented doublets, which are used for numerical aperture matching and act as relay lenses to focus the light from the fiber collimator onto the imaging surface of the objective lens, preventing the light spot from spreading continuously during long-distance transmission. Specifically, the diameter of the achromatic cemented doublet is 10mm, its focal length is 20mm, and the wavelength range of the achromatic cemented doublet is 400-1000nm.

[0040] Meanwhile, the first objective lens 15 and the second objective lens 23 are long-working-distance objectives, providing a physical dimension basis for large-range angle measurements. Specifically, in this embodiment, the first objective lens 15 and the second objective lens 23 use a single magnification, mainly to ensure that the size of the excitation spot is consistent with the size of the front-projected spot, thus guaranteeing the spot size. In specific operations, the appropriate magnification can be selected based on actual conditions, but it must be ensured that the effect after use is consistent with the above.

[0041] The light source device 10 includes a 250W bulb, which is a 250W spherical high-pressure, short-arc xenon lamp.

[0042] Specifically, this optical path model also includes a coaxial rotating arm. In practical applications, the excitation end unit 1 and the collection end unit 2 are respectively installed at the two ends of the symmetrical arm of the coaxial rotating arm, symmetrically distributed around the rotation axis of the coaxial rotating arm, and can move synchronously and coaxially around the rotation axis. During the movement, the optical path angle between the two remains symmetrical, and the intersection of the optical paths is always located on the sample surface. The coaxial rotating arm allows the excitation end and the collection end to move synchronously and coaxially around the rotation axis, ensuring that the optical path angle between the two remains symmetrical during the movement (e.g., when the incident angle is θ, the receiving angle is also θ), avoiding "excitation and collection mismatch" caused by asymmetrical angles (e.g., incident θ, receiving φ ≠ θ), and accurately achieving angle-resolved detection.

[0043] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims, and all such changes shall be within the scope of protection of the present invention.

Claims

1. A micro-region adjustable optical path model for an angle-resolved spectral system, characterized in that, It includes an excitation end unit and a collection end unit, and the optical paths of the excitation end unit and the collection end unit have a convergence point; The excitation end unit sequentially includes a light source device, a first optical fiber for light transmission, a first optical fiber collimator connected to the light source device via the first optical fiber, a polarizer for converting light into a specific polarization state to excite surface plasmons, a first cemented doublet lens for numerical aperture matching and focusing the light output from the first optical fiber collimator and the polarizer onto the imaging surface of the objective lens, a first objective lens for focusing the light spot projected onto its imaging surface by the first cemented doublet lens at a single magnification onto the sample surface to achieve spot micro-regioning, and an aperture stop disposed between the first cemented doublet lens and the first objective lens. The collection unit includes, in sequence, a spectrometer, a second optical fiber, a second optical fiber collimator connected to the spectrometer via an optical fiber, a second cemented doublet lens, and a second objective lens for collecting light emitted from the sample. The collecting end unit and the excitation end unit are symmetrically distributed, and except for the polarizer, aperture and light source device installed in the excitation end unit, and the spectrometer connected to the collecting end unit, the other optical elements of the excitation end unit and the collecting end unit are completely identical.

2. The micro-region adjustable optical path model for an angle-resolved spectral system according to claim 1, characterized in that: The light source device includes a 250W bulb, which is a 250W spherical high-pressure, short-arc xenon lamp.

3. The micro-region adjustable optical path model for an angle-resolved spectral system according to claim 1, characterized in that: Both the excitation end unit and the collection end unit are equipped with adjustment mechanisms, which include a five-dimensional adjustment frame for adjusting the position of the fiber collimator and a four-dimensional adjustment frame for adjusting the position of the cemented doublet lens. The five-dimensional adjustment frame is equipped with an optical fiber collimator adapter, and the first optical fiber collimator and the second optical fiber collimator are fixed by their respective optical fiber collimator adapters; the four-dimensional adjustment frame is equipped with a cemented doublet lens mounting adapter ring, and the first cemented doublet lens and the second cemented doublet lens are fixed by their respective cemented doublet lens mounting adapter rings.

4. The micro-region adjustable optical path model for an angle-resolved spectral system according to claim 1, characterized in that: The excitation end unit is also provided with a two-dimensional adjustment frame, which is located between the four-dimensional adjustment frame and the objective lens, and between the first cemented doublet lens and the aperture. The aperture is fixedly installed on the bearing surface of the two-dimensional adjustment frame, and the two-dimensional adjustment frame can drive the aperture to translate and adjust along the X-axis and Y-axis in a plane perpendicular to the optical axis of the optical path.

5. The micro-region adjustable optical path model for an angle-resolved spectral system according to claim 1, characterized in that: The aperture of the aperture is 20 micrometers.

6. The micro-region adjustable optical path model for an angle-resolved spectral system according to claim 1, characterized in that: The excitation end unit also includes a rotating mirror frame, which is located between the five-dimensional adjustment frame and the four-dimensional adjustment frame, and between the first fiber collimator and the polarizer. The polarizer is fixedly mounted on the bearing surface of the rotating frame. The rotating frame can drive the polarizer to rotate around the optical axis of the optical path to adjust the polarization angle.

7. The micro-region adjustable optical path model for an angle-resolved spectral system according to claim 1, characterized in that: Both the first and second optical fibers are made of quartz multimode fiber and the cladding is made of fluorine-doped quartz material. The diameter of the first optical fiber is 50 micrometers and the diameter of the second optical fiber is 1000 micrometers. The numerical aperture of the first optical fiber is 0.12 and the numerical aperture of the second optical fiber is 0.

22.

8. The micro-region adjustable optical path model for an angle-resolved spectral system according to claim 1, characterized in that: Both the first cemented doublet and the second cemented doublet are achromatic cemented doublets.

9. The micro-region adjustable optical path model for an angle-resolved spectral system according to claim 8, characterized in that: The achromatic cemented doublet has a diameter of 10mm and a focal length of 20mm, and the wavelength range of the achromatic cemented doublet is 400-1000nm.

10. The micro-region adjustable optical path model for an angle-resolved spectral system according to claim 1, characterized in that: Both the first objective and the second objective are long working distance objectives.

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