High-resolution liquid drop spectrophotometer

Abstract

The invention relates to a high-resolution liquid drop light splitting spectrometer, relates to the technical field of spectrometers, and solves the technical problem that a spectrometer in the prior art is difficult to realize low-cost and high-precision spectrum detection. The high-resolution liquid drop spectrophotometer comprises a lens coupling system, an optical fiber, a diaphragm, a liquid carrying sheet, a point detector and a signal acquisition and processing unit, a liquid drop generation device is arranged near the liquid carrying sheet and is used for accurately controlling the volume and the generation frequency of liquid drops generated on the liquid carrying sheet. The high-resolution liquid drop spectrophotometer is suitable for application occasions with strict requirements on cost and high resolution, such as the fields of biomedical detection, environmental monitoring, material analysis and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of spectrometers, and particularly to a high-resolution droplet spectroscopic spectrometer. Background Art

[0002] A spectrum refers to a pattern formed by arranging a composite light in sequence according to its wavelength or frequency after being split by a spectroscope. The spectral range and spectral resolution are the key indicators for evaluating the spectral performance of a spectrometer: the larger the spectral range, the broader the detected spectrum; the higher the spectral resolution, the finer the detected spectrum. High spectral resolution and wide spectral range both mean more spectral bands and richer spectral information. Therefore, it is very meaningful to simultaneously achieve a larger spectral range and a higher spectral resolution.

[0003] Most of the spectrometers in the prior art are designed based on spectroscopic elements such as gratings and prisms, including: interferometric spectrometers based on Michelson interferometers and spatial modulation interferometric imaging, prism spectrometers, Fourier transform spectrometers, etc. Among them, interferometric spectrometers have strict requirements for the machining accuracy and transmission accuracy of mechanical structures, poor anti-vibration ability, and poor real-time performance. Prism spectrometers have poor linearity of spectral resolution and large volume; Fourier transform spectrometers have complex structures and high costs. The spectrometers in the prior art are difficult to achieve low-cost and high-precision spectral detection, and their cost and volume are the main reasons hindering the widespread civilian use of spectrometers. Summary of the Invention

[0004] The present invention aims to solve the technical problem that spectrometers in the prior art are difficult to achieve low-cost and high-precision spectral detection, and provides a high-resolution droplet spectroscopic spectrometer.

[0005] To solve the above technical problems, the technical solution of the present invention is specifically as follows:

[0006] A high-resolution droplet spectroscopic spectrometer includes, in sequence along the optical path direction: a lens coupling system, an optical fiber, a diaphragm, a liquid carrier sheet, a point detector, and a signal acquisition and processing unit; a droplet generation device is provided near the liquid carrier sheet, and this droplet generation device is used to precisely control the volume and generation frequency of the droplets generated on the liquid carrier sheet;

[0007] The lens coupling system is used to collimate and focus the incident light to ensure that the light enters the optical fiber at an appropriate angle and intensity;

[0008] The optical fiber is used to guide the light to the droplet position;

[0009] The diaphragm is arranged at the end of the optical fiber and is used to precisely control the spot size and shape of the light entering the droplets on the liquid carrier sheet;

[0010] The point detector is used to capture the spectral signals of the light emitted by the droplets on the liquid carrier sheet;

[0011] The signal acquisition and processing unit is used to quickly acquire and digitally process the electrical signals output by the point detector.

[0012] In the above technical solution, the surface of the liquid carrier sheet is coated with a neutral material coating having chemical stability and low surface energy characteristics.

[0013] In the above technical solution, the droplet generating device is a high-precision micro-injection pump.

[0014] In the above technical solution, the spectral response range of the point detector includes: 400 - 800 nm.

[0015] In the above technical solution, a high-speed data acquisition card is equipped in the signal acquisition and processing unit.

[0016] In the above technical solution, the liquid material used to generate droplets is: isopropyl alcohol, ethanol, water, cyclohexasiloxane or fluorinated liquid.

[0017] The present invention has the following beneficial effects:

[0018] The high-resolution droplet spectro-spectrometer of the present invention uses the self-evaporation process of the liquid as the key step for the spectrometer to split light; the spectrometer collects the scattered light from the outside, and after collection, it is transmitted to the self-evaporating liquid. Since the liquid is volatile, the slope of each region changes regularly. The light beam is focused on a certain region of the liquid. Through continuous curvature changes, the spectral distribution on the image plane will move continuously with the evaporation of the liquid. The point detector can record the spectral energy distribution of the wide band within a very short liquid evaporation time (120 s), so as to achieve excellent performance and be able to complete accurate spectral detection with a spectral resolution of 2 nm in the wavelength range of 400 - 800 nm.

[0019] The high-resolution droplet spectro-spectrometer of the present invention is applicable to application scenarios with strict requirements for both cost and high resolution, such as biomedical detection, environmental monitoring, and material analysis and other fields.

[0020] The high-resolution droplet spectro-spectrometer of the present invention uses the liquid as a special key optical device of the spectrometer, which can solve the complex optical path of the traditional spectrometer while meeting the requirements of low cost, high spectral resolution, and flexible tuning.

[0021] The high-resolution droplet spectro-spectrometer of the present invention introduces a self-evaporating liquid as the key light-splitting device, and a point detector is sufficient, so that the instrument can be small in size, short in spectral acquisition time, and low in price. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0023] Figure 1 This is a schematic structural diagram of the high-resolution droplet spectroscope of the present invention.

[0024] Figure 2 This is a schematic diagram for comparing the dispersion rates of volatile liquids.

[0025] Figure 3 This is a schematic diagram of the change in the liquid surface cut angle (angle of incidence) at the incident point during spectral detection using the high-resolution droplet spectroscope of the present invention.

[0026] Figure 4 This is a schematic diagram of the change in the angle of incidence within 120 s at different wavelengths during spectral detection using the high-resolution droplet spectroscope of the present invention.

[0027] The reference signs in the figure are as follows:

[0028] 1 - lens coupling system; 2 - optical fiber; 3 - aperture; 4 - liquid carrier sheet; 5 - point detector; 6 - signal acquisition and processing unit; 7 - droplet generation device; 8 - droplet. Detailed implementation manners

[0029] The inventive concept of the present invention is as follows:

[0030] The high-resolution droplet spectroscope of the present invention is based on the characteristic of droplet evaporation, and uses the subtle change in the shape of the liquid surface during the evaporation process of the droplet to achieve spectral splitting. When the spectral lines after spectral splitting cause the liquid surface to move due to the continuous change of the liquid surface, a point detector is used to collect the moving spectral information, thereby achieving spectral detection with high spectral resolution and low cost.

[0031] Specifically, the high-resolution droplet spectroscope of the present invention is based on the refraction and dispersion phenomena of light. When light enters the droplet, due to the different refractive indices of the droplet material (such as alcohol) for light of different wavelengths, light of different wavelengths undergoes dispersion. As the droplet evaporates, its shape gradually changes, and the curvature and inclination angle of the liquid surface also change accordingly, causing the propagation path of the dispersed light to change and resulting in the separation of light of different wavelengths in space. The spectral lines after spectral splitting move on the image plane due to the change of the liquid surface, and the point detector is accurately arranged on the path of the spectral movement. The high-resolution droplet spectroscope of the present invention resolves complete spectral information by continuously collecting spectral signals that change with time and using the "time - wavelength" correspondence relationship.

[0032] For the high-resolution droplet spectroscope of the present invention, liquids with many excellent properties such as alcohol are selected for droplet evaporation. Such liquids have a good linearity of the dispersion curve, and have the characteristics of easy evaporation, no irritation, non-toxicity, and relatively high transmittance in the visible and near-infrared bands.

[0033] The present invention will be described in detail below with reference to the accompanying drawings.

[0034] As Figure 1 shown, the high-resolution droplet spectro-spectrometer of the present invention includes, successively arranged in the optical path direction: a lens coupling system 1, an optical fiber 2, a diaphragm 3, a liquid carrier sheet 4, a point detector 5, and a signal acquisition and processing unit 6; a droplet generation device 7 is provided near the liquid carrier sheet 4, and the droplet generation device 7 is used to precisely control the volume and generation frequency of the droplets 8 generated on the liquid carrier sheet 4;

[0035] The lens coupling system 1 is used to collimate and focus the incident light to ensure that the light enters the optical fiber 2 at an appropriate angle and intensity;

[0036] The optical fiber 2 is used to guide the light to the position of the droplet 8;

[0037] The diaphragm 3 is arranged at the end of the optical fiber 2 and is used to precisely control the spot size and shape of the light entering the droplet 8 on the liquid carrier sheet 4;

[0038] The point detector 5 is used to capture the spectral signal of the light emitted by the droplet 8 on the liquid carrier sheet 4;

[0039] The signal acquisition and processing unit 6 is used to quickly acquire and digitally process the electrical signal output by the point detector 5.

[0040] Specifically:

[0041] The lens coupling system 1 adopts a lens group with high light transmittance and low aberration, such as a 4f system, to efficiently collimate and focus the incident light, ensure that the light enters the optical fiber 2 at an appropriate angle and intensity, and improve the light transmission efficiency.

[0042] The optical fiber 2 adopts an optical fiber with low loss and core diameter adaptation to ensure that the optical signal has the minimum loss during transmission and can precisely guide the light to the position of the droplet 8.

[0043] The diaphragm 3 is an adjustable diaphragm, which can precisely control the spot size and shape of the light entering the droplet 8, optimize the light incident conditions, and reduce the interference of stray light.

[0044] The surface of the liquid carrier sheet 4 is coated with a neutral material coating of polydimethylsiloxane (PDMS) material to reduce the interaction between the droplet 8 and the stage 4 and ensure the stability and repeatability of the evaporation process of the droplet 8. The coating material of the neutral material coating has characteristics such as chemical stability and low surface energy.

[0045] The droplet generation device 7 is a high-precision micro-injection pump, which can precisely control the volume and generation frequency of the droplet 8 to ensure the consistency of the initial conditions of the droplet 8 in each experiment.

[0046] The point detector 5 has high sensitivity and a wide spectral response range, such as a photomultiplier tube or a high-performance photodiode, to ensure that weak spectral signals can be accurately captured and the target wavelength range of 400 - 800 nm is covered.

[0047] The signal acquisition and processing unit 6 is equipped with a high-speed data acquisition card, which is used to quickly acquire and digitally process the electrical signals output by the point detector 5, and perform real-time analysis, processing, and display on the acquired data to obtain the final spectral results.

[0048] The liquid material used to generate the droplet 8 can be selected from isopropanol, ethanol, water, cyclohexasiloxane, or fluorinated liquid. In this embodiment, alcohol is selected as the liquid material for the droplet 8. Alcohol has a good linearity of the dispersion curve, which is beneficial to achieving precise spectral separation; the volatile property of alcohol enables obvious changes in the liquid surface shape to occur within a short time, meeting the requirements of rapid spectral detection; alcohol is non-irritating and non-toxic, ensuring the safety of the experimental environment; the high transmittance in the visible near-infrared band guarantees the effective transmission of optical signals. In other specific embodiments, other liquid materials can be flexibly selected according to the specific requirements of the experimental conditions, such as Figure 2 as shown in Table 1, which will not be elaborated here.

[0049] Table 1 Selection of Liquid Materials

[0050]

[0051] The specific working process of the high-resolution droplet spectroscopic spectrometer of the present invention is as follows:

[0052] The incident light is first coupled by the lens in the lens coupling system 1 and smoothly enters the optical fiber 2.

[0053] Subsequently, the light emerging from the optical fiber 2 passes through the aperture 3 and precisely reaches a position at a certain distance from the center of the droplet 8.

[0054] As the droplet 8 continuously volatilizes, the angle between the liquid surface section at this position and the liquid-carrying sheet 4 coated with a neutral material coating continuously decreases, and this change causes the spectroscopically separated spectrum to move on the image plane over time; the spectral signals are continuously and stably acquired by the point detector 5, and high-precision detection of spectral information is achieved using the signal acquisition and processing unit 6.

[0055] Such as Figure 3As shown, the self-volatile droplet 8, which is a key spectroscopic device, shows an approximately linear change in the angle between the tangent plane of the liquid surface and the liquid-carrying surface as it continuously volatilizes. This indicates that the high-resolution droplet spectroscopic spectrometer of the present invention has excellent uniformity in spectral resolution. In a short period of time, the change in the angle between the tangent plane of the liquid surface and the liquid-carrying surface is approximately linear, and the spectral distribution on the image plane gradually moves. Exactly, all the optical signals are collected by the point detector 5. Moreover, except under harsh conditions, the high-resolution droplet spectroscopic spectrometer of the present invention has strong practicability, is inexpensive, and has a small volume.

[0056] As Figure 4 shown, because the point detector 5 has a response time, within one unit of response time, the change in the detection wavelength corresponding to the movement of the spectral distribution on the image plane is the spectral resolution. Through Figure 4 calculation, it can be obtained that if the focal length is selected as 60 mm, the spectral resolution can be better than 2 nm. More remarkably, the spectral resolution is very uniform. When a larger focal length is selected, the spectral resolution is better. However, energy should be considered. After some energy transmission calculations, it is most appropriate to select a focal length of 60 mm.

[0057] The high-resolution droplet spectroscopic spectrometer of the present invention uses the self-volatile process of the liquid as the key step for spectroscopic splitting of the spectrometer. The spectrometer collects the scattered light from the outside, and after collection, it is transmitted to the self-volatile liquid. Since the liquid is volatile, the slope of each region changes regularly. The light beam is focused on a certain region of the liquid. Through continuous curvature changes, the spectral distribution on the image plane will continuously move as the liquid volatilizes. The point detector can record the spectral energy distribution of the broadband within a very short liquid volatilization time (120 s), thus achieving excellent performance and being able to complete precise spectral detection with a spectral resolution of 2 nm within the wavelength range of 400 - 800 nm.

[0058] The high-resolution droplet spectroscopic spectrometer of the present invention is applicable to application scenarios with strict requirements for both cost and high resolution, such as biomedical detection, environmental monitoring, and material analysis.

[0059] The high-resolution droplet spectroscopic spectrometer of the present invention uses the liquid as a special key optical device of the spectroscopic instrument. It can solve the complex optical path of the traditional spectrometer while meeting the requirements of low cost, high spectral resolution, and flexible tuning.

[0060] The high-resolution droplet spectroscopic spectrometer of the present invention introduces a self-volatile liquid as the key spectroscopic device, and a point detector is sufficient for the detector, thereby enabling the instrument to have a small volume, a short spectral acquisition time, and a low price.

[0061] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims

1. A high-resolution droplet spectroscopic spectrometer, characterized in that, Including, arranged successively in the optical path direction: a lens coupling system (1), an optical fiber (2), a diaphragm (3), a liquid-carrying sheet (4), a point detector (5), and a signal acquisition and processing unit (6); near the liquid-carrying sheet (4), there is a droplet generation device (7), and this droplet generation device (7) is used to precisely control the volume and generation frequency of the droplets (8) generated on the liquid-carrying sheet (4); The lens coupling system (1) is used to collimate and focus the incident light to ensure that the light enters the optical fiber (2) at an appropriate angle and intensity; The optical fiber (2) is used to guide the light to the position of the droplet (8); The diaphragm (3) is arranged at the end of the optical fiber (2) and is used to precisely control the spot size and shape of the light entering the droplet (8) on the liquid-carrying sheet (4); The point detector (5) is used to capture the spectral signal of the light emitted by the droplet (8) on the liquid-carrying sheet (4); The signal acquisition and processing unit (6) is used to quickly acquire and digitally process the electrical signal output by the point detector (5).

2. The high-resolution droplet spectroscopic spectrometer according to claim 1, wherein The surface of the liquid-carrying sheet (4) is coated with a neutral material coating with chemical stability and low surface energy characteristics.

3. The high-resolution droplet spectroscopic spectrometer according to claim 1, characterized in that, The droplet generation device (7) is a high-precision micro-injection pump.

4. The high-resolution droplet spectroscope according to claim 1, wherein The spectral response range of the point detector (5) includes: 400 - 800 nm.

5. The high-resolution droplet spectro-spectrometer according to claim 1, characterized in that, The signal acquisition and processing unit (6) is equipped with a high-speed data acquisition card.

6. The high-resolution droplet spectroscope according to claim 1, characterized in that, The liquid material used to generate the droplet (8) is: isopropyl alcohol, ethanol, water, cyclohexasiloxane, or a fluorinated liquid.

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