阅读说明：本技术 一种基于贝塞尔光的便携式拉曼光谱仪 (Portable Raman spectrometer based on Bessel light ) 是由 陈雪利 任枫 占自银 杨上 王浩宇 曾琦 于 2020-03-31 设计创作，主要内容包括：本发明涉及一种基于贝塞尔光的便携式拉曼光谱仪,包括激光器、贝塞尔光生成模块、样本台、拉曼信号收集模块和光谱仪,其中,激光器,用于通过传输光纤或空间自由光方式发射高斯光束；贝塞尔光生成模块,用于将激光器发射的高斯光束转换成贝塞尔光束,并将贝塞尔光束照射到样本上激发出瑞利散射信号和拉曼散射信号；样本台,用于放置样本,样本被所述贝塞尔光束照射后激发出瑞利散射信号和拉曼散射信号；拉曼信号收集模块,用于收集样本透射的瑞利散射信号和拉曼散射信号,并滤除瑞利散射信号,保留拉曼散射信号,耦合拉曼散射信号到光谱仪；光谱仪,用于接收拉曼信号收集模块收集的拉曼散射信号。本发明的模块化设计,使安装和携带更加方便。(The invention relates to a Bessel light-based portable Raman spectrometer, which comprises a laser, a Bessel light generation module, a sample stage, a Raman signal collection module and a spectrometer, wherein the laser is used for emitting Gaussian beams in a transmission optical fiber or space free light mode; the Bessel light generation module is used for converting the Gaussian beam emitted by the laser into a Bessel beam and irradiating the Bessel beam on the sample to excite a Rayleigh scattering signal and a Raman scattering signal; the sample stage is used for placing a sample, and the sample is irradiated by the Bessel beam and then excited to generate a Rayleigh scattering signal and a Raman scattering signal; the Raman signal collection module is used for collecting a Rayleigh scattering signal and a Raman scattering signal transmitted by the sample, filtering the Rayleigh scattering signal, retaining the Raman scattering signal and coupling the Raman scattering signal to the spectrometer; and the spectrometer is used for receiving the Raman scattering signals collected by the Raman signal collection module. The modular design of the invention makes the installation and carrying more convenient.)

1. A portable Raman spectrometer based on Bessel light is characterized by comprising a laser (1), a Bessel light generation module (2), a sample stage (3), a Raman signal collection module (4) and a spectrometer (5),

the laser (1) is used for emitting Gaussian beams through a transmission optical fiber or a space free light mode;

the Bessel light generation module (2) converts the Gaussian beam emitted by the laser (1) into a Bessel beam and irradiates the Bessel beam to a sample;

the sample stage (3) is used for placing a sample, and the sample is irradiated by the Bessel light beam to excite the Rayleigh scattering signal and the Raman scattering signal;

the Raman signal collection module (4) is used for collecting the Rayleigh scattering signal and the Raman scattering signal transmitted by the sample, filtering the Rayleigh scattering signal, retaining the Raman scattering signal and coupling the Raman scattering signal to the spectrometer (5);

the spectrometer (5) is used for receiving the Raman scattering signals collected by the Raman signal collecting module (4).

2. The Bessel-light-based portable Raman spectrometer according to claim 1, wherein the Bessel-light generation module (2) comprises a first beam quality optimization module (211), a first mirror (212), and a first Bessel-light generation module (213), the first beam quality optimization module (211) and the first mirror (212) being arranged in sequence along an optical path of a first Gaussian beam emitted by the laser (1), the first Bessel-light generation module (213) being arranged along a reflection direction of the first mirror (212), wherein,

the first light beam quality optimization module (211) is used for performing spatial filtering, spectral filtering and beam expanding on the first Gaussian light beam emitted by the laser (1) to obtain a first optimized light beam;

the first mirror (212) for reflecting the first optimized light beam onto the first Bessel light generation module (213);

the first Bessel light generation module (213) is used for converting the first optimized light beam reflected to the first Bessel light generation module (213) into a first Bessel light beam, and the first Bessel light beam irradiates on the sample to excite a first Rayleigh scattering signal and a first Raman scattering signal.

3. The Bessel-light-based portable Raman spectrometer according to claim 2, wherein the Raman signal collection module (4) comprises a first converging lens (411), a second mirror (412), a first filtering module (413), and a first coupling lens (414), the first converging lens (411) and the second mirror (412) being sequentially disposed along the optical paths of the first Rayleigh scattering signal and the first Raman scattering signal, the first filtering module (413) and the first coupling lens (414) being sequentially disposed along the optical paths of the first Rayleigh scattering signal and the first Raman scattering signal reflected by the second mirror (412), wherein,

the first focusing lens (411) for focusing the first Rayleigh scattering signal and the first Raman scattering signal transmitted by the sample onto the second mirror (412);

the second mirror (412) for reflecting the first rayleigh scatter signal and the first raman scatter signal converged on the second mirror (412) onto the first filtering module (413);

the first filtering module (413) is configured to filter the first rayleigh scattering signal reflected to the first filtering module (413) and retain the first raman scattering signal;

the first coupling lens (414) for coupling the first Raman scattered signal to the spectrometer (5).

4. The Bessel-light-based portable Raman spectrometer according to claim 1, characterized in that the Bessel-light generation module (2) comprises a second beam quality optimization module (221) and a second Bessel-light generation module (222), the second beam quality optimization module (221) and the second Bessel-light generation module (222) being arranged in sequence along the optical path of a second Gaussian beam emitted by the laser (1), wherein,

the second light beam quality optimization module (221) is configured to perform spatial filtering, spectral filtering and beam expanding on the second gaussian light beam emitted by the laser (1) to obtain a second optimized light beam;

the second Bessel light generation module (222) is configured to convert the second optimized light beam into a second Bessel light beam, and the second Bessel light beam impinging on the sample excites a second Rayleigh scattering signal and a second Raman scattering signal.

5. The Bessel-light-based portable Raman spectrometer according to claim 4, wherein the Raman signal collection module (4) comprises a second converging lens (421), a third mirror (422), a second filtering module (423), and a second coupling lens (424), the second converging lens (421) and the third mirror (422) being arranged in sequence along the optical paths of the second Rayleigh scattering signal and the second Raman scattering signal, the second filtering module (423) and the second coupling lens (424) being arranged in sequence along the reflection direction of the third mirror (422), wherein,

the second converging lens (421) for converging the second Rayleigh scattered signal and the second Raman scattered signal transmitted by the sample onto the third mirror (422);

the third mirror (422) is used for reflecting the second Rayleigh scattering signal and the second Raman scattering signal converged by the second converging lens (421) to the second filtering module (423);

the second filtering module (423) is configured to filter the second rayleigh scattering signal reflected by the third mirror (422) and retain the second raman scattering signal;

the second coupling lens (424) for coupling the second Raman scattering signal to the spectrometer (5).

6. The Bessel-light-based portable Raman spectrometer according to claim 1, characterized in that the Bessel-light generation module (2) comprises a third coupling lens (231) and a fiber-optic module (232), the third coupling lens (231) and the fiber-optic module (232) being arranged in sequence along the optical path of a third Gaussian beam emitted by the laser (1), wherein,

the third coupling lens (231) is used for coupling the third Gaussian beam emitted by the laser (1) to obtain a fourth Gaussian beam;

the optical fiber module (232) is used for converting the fourth Gaussian beam into a third Bessel beam, and the third Bessel beam irradiates on the sample to excite a third Rayleigh scattering signal and a third Raman scattering signal.

7. The Bessel-light-based portable Raman spectrometer according to claim 6, wherein the Raman signal collection module (4) comprises a third converging lens (431), a fourth reflecting mirror (432), a third filtering module (433) and a fourth coupling lens (434), the third converging lens (431) and the fourth reflecting mirror (432) being arranged in sequence along the optical paths of the third Rayleigh scattering signal and the third Raman scattering signal, the third filtering module (433) and the fourth coupling lens (434) being arranged in sequence along the reflection direction of the fourth reflecting mirror (432), wherein,

the third converging lens (431) for converging the third Rayleigh scattered signal and the third Raman scattered signal transmitted by the sample to the fourth mirror (432);

the fourth mirror (432) is configured to reflect the third rayleigh scattering signal and the third raman scattering signal converged by the third converging lens (431) to the third filtering module (433);

the third filtering module (433) is configured to filter the third rayleigh scattering signal reflected by the fourth mirror (432) and retain the third raman scattering signal;

the fourth coupling lens (434) for coupling the third Raman scattered signal to the spectrometer (5).

Technical Field

The invention belongs to the technical field of Raman spectroscopy, and particularly relates to a Bessel light-based portable Raman spectrometer.

Background

The raman spectrum is a vibration spectrum of molecules, different substances are composed of different chemical structures, and the raman spectrum is reflected that the different substances have different raman spectrum curves, for example, fingerprints of two persons are completely the same in the world, and the raman spectra of the different substances are different. When a sample is analyzed by a Raman spectrum technology, a light source is monochromatic light with a certain frequency, and when the monochromatic light enters a medium, two different scattering processes can be generated, wherein the frequency of one type of scattering light is the same as the frequency of the incident light and is called Rayleigh scattering light; the other type of scattering light has a frequency different from that of incident light and becomes raman scattering light, and the raman spectroscopy technology analyzes a material structure by using the scattering light in which the frequency changes, and is currently applied to the fields of biomedicine, pharmaceutical chemistry, criminal investigation, material science, food safety, environmental monitoring and the like.

The traditional Raman spectrometer needs to be placed in a specific environment for use, so that the influence of ambient light or other interference light sources is avoided, Gaussian beams are adopted to expand and irradiate a sample to acquire signals, and the Raman spectrometer can only focus on the surface of the sample for analysis due to the fact that the Gaussian beams are diffracted in the free space and the influence of a lens.

The traditional Raman detection technology mainly has two problems, namely, the structure is complex, the assembly is complicated, and the carrying is difficult; secondly, the raman spectrometer cannot well perform deep analysis and identification on thick transparent samples, weak scattering samples and millimeter-sized thickness scattering samples.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a portable Raman spectrometer based on Bessel light.

One embodiment of the invention provides a Bessel light-based portable Raman spectrometer comprising a laser, a Bessel light generation module, a sample stage, a Raman signal collection module and a spectrometer, wherein,

the laser is used for emitting Gaussian beams in a transmission optical fiber or space free light mode;

the Bessel light generation module is used for converting the Gaussian beam emitted by the laser into a Bessel beam and irradiating the Bessel beam to a sample;

the sample stage is used for placing a sample, and the sample is irradiated by the Bessel beam to excite the Rayleigh scattering signal and the Raman scattering signal;

the Raman signal collection module is used for collecting the Rayleigh scattering signal and the Raman scattering signal transmitted by the sample, filtering the Rayleigh scattering signal, retaining the Raman scattering signal and coupling the Raman scattering signal to the spectrometer;

the spectrometer is used for receiving the Raman scattering signals collected by the Raman signal collecting module.

In one embodiment of the present invention, the bessel light generation module includes a first beam quality optimization module, a first mirror, and a first bessel light generation module, the first beam quality optimization module and the first mirror are sequentially disposed along an optical path of a first gaussian beam emitted from the laser, the first bessel light generation module is disposed along a reflection direction of the first mirror, wherein,

the first light beam quality optimization module is used for performing spatial filtering, spectral filtering and beam expanding on the first Gaussian light beam emitted by the laser to obtain a first optimized light beam;

the first mirror is used for reflecting the first optimized light beam to the first Bessel light generation module;

the first Bessel light generation module is used for converting the first optimized light beam reflected to the first Bessel light generation module into a first Bessel light beam, and the first Bessel light beam irradiates the sample to excite a first Rayleigh scattering signal and a first Raman scattering signal.

In one embodiment of the present invention, the raman signal collection module comprises a first converging lens, a second reflecting mirror, a first filtering module and a first coupling lens, the first converging lens and the second reflecting mirror are sequentially disposed along the optical paths of the first rayleigh scattering signal and the first raman scattering signal, the first filtering module and the first coupling lens are sequentially disposed along the optical paths of the first rayleigh scattering signal and the first raman scattering signal reflected by the second reflecting mirror, wherein,

the first focusing lens is used for focusing the first Rayleigh scattering signal and the first Raman scattering signal transmitted by the sample to the second reflecting mirror;

the second mirror for reflecting the first rayleigh scattering signal and the first raman scattering signal focused onto the second mirror onto the first filtering module;

the first filtering module is used for filtering the first Rayleigh scattering signal reflected to the first filtering module and retaining the first Raman scattering signal;

the first coupling lens is used for coupling the first Raman scattering signal to the spectrometer.

In one embodiment of the present invention, the bessel light generation module includes a second beam quality optimization module and a second bessel light generation module, which are sequentially disposed along an optical path of a second gaussian beam emitted by the laser, wherein,

the second light beam quality optimization module is used for performing spatial filtering, spectral filtering and beam expanding on the second Gaussian light beam emitted by the laser to obtain a second optimized light beam;

the second bessel light generation module is used for converting the second optimized light beam into a second bessel light beam, and the second bessel light beam irradiates on the sample to excite a second Rayleigh scattering signal and a second Raman scattering signal.

In an embodiment of the present invention, the raman signal collection module includes a second converging lens, a third reflecting mirror, a second filtering module and a second coupling lens, the second converging lens and the third reflecting mirror are sequentially disposed along optical paths of the second rayleigh scattering signal and the second raman scattering signal, the second filtering module and the second coupling lens are sequentially disposed along a reflecting direction of the third reflecting mirror, wherein,

the second converging lens is used for converging the second Rayleigh scattering signal and the second Raman scattering signal transmitted by the sample to the third reflecting mirror;

the third reflector is configured to reflect the second rayleigh scattering signal and the second raman scattering signal converged by the second converging lens to the second filtering module;

the second filtering module is configured to filter the second rayleigh scattering signal reflected by the third mirror and retain the second raman scattering signal;

the second coupling lens is used for coupling the second Raman scattering signal to the spectrometer.

In one embodiment of the invention, the bessel light generation module comprises a third coupling lens and a fiber module, which are arranged in sequence along the optical path of a third gaussian beam emitted by the laser, wherein,

the third coupling lens is used for coupling the third Gaussian beam emitted by the laser to obtain a fourth Gaussian beam;

the optical fiber module is used for converting the fourth Gaussian beam into a third Bessel beam, and the third Bessel beam irradiates a sample to excite a third Rayleigh scattering signal and a third Raman scattering signal.

In an embodiment of the present invention, the raman signal collection module includes a third converging lens, a fourth reflecting mirror, a third filtering module and a fourth coupling lens, the third converging lens and the fourth reflecting mirror are sequentially disposed along optical paths of the third rayleigh scattering signal and the third raman scattering signal, the third filtering module and the fourth coupling lens are sequentially disposed along a reflecting direction of the fourth reflecting mirror, wherein,

the third converging lens is used for converging the third Rayleigh scattering signal and the third Raman scattering signal transmitted by the sample to the fourth reflecting mirror;

the fourth mirror is configured to reflect the third rayleigh scattering signal and the third raman scattering signal converged by the third converging lens to the third filtering module;

the third filtering module is configured to filter the third rayleigh scattering signal reflected by the fourth mirror and retain the third raman scattering signal;

the fourth coupling lens is configured to couple the third raman scattering signal to the spectrometer.

In one embodiment of the invention, the sample stage is a means for holding and holding a sample.

Compared with the prior art, the invention has the beneficial effects that:

the invention provides a Bessel light-based portable Raman spectrometer which comprises a laser, a Bessel light generation module, a sample table, a Raman signal collection module and a spectrometer, wherein the laser, the Bessel light generation module, the sample table, the Raman signal collection module and the spectrometer are simultaneously packaged in the Bessel light-based portable Raman spectrometer, so that the system is modularized, and the assembly and the carrying are more convenient. Meanwhile, by utilizing the nature of no diffraction and self-recovery of the Bessel beam, deeper detection can be performed on thick transparent samples, weak scattering samples and scattering samples with millimeter-scale thickness, and the signal-to-noise ratio of the Raman spectrum of the detected samples is improved.

Drawings

Fig. 1 is a schematic block diagram of a portable raman spectrometer based on bessel light according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a first structure of a Bessel light-based portable Raman spectrometer provided by an embodiment of the present invention;

FIG. 3 is a second structural diagram of a Bessel light-based portable Raman spectrometer according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a third type of a portable raman spectrometer based on bessel light according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the embodiments of the present invention are not limited thereto.