CN210401221U

CN210401221U - Multi-hot-spot excitation primary feedback Raman spectrum testing device in liquid environment

Info

Publication number: CN210401221U
Application number: CN201920635517.6U
Authority: CN
Inventors: 张新平; 刘淼
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2019-05-06
Filing date: 2019-05-06
Publication date: 2020-04-24
Anticipated expiration: 2029-05-06

Abstract

A multi-hot-spot excitation primary feedback Raman spectrum testing device in a liquid environment belongs to the technical field of optical sensors for environmental protection and environmental monitoring. Comprises multiple concave reflectors, wherein along the propagation direction of light path, the excitation light is collimated by optical filtering and then incident on the first concave reflector in liquid, the reflected light beam forms a first focus, and a distance r is arranged behind the first focus along the light path₁The rear part is a second concave reflector, the second concave reflector reflects the light beam to form a second focus, and the like, n concave reflectors are arranged; the light reflected by the n-1 th concave reflector forms the n-1 focus, the nth concave reflector is vertical to the incident beam; the reflected light from the previous concave mirror is used as the incident light from the next concave mirror. The utility model discloses introduce raman spectrum testing arrangement with multifocal optical system, increase the number of hot spots, promote raman spectrum test performance and reach the level that the trace detected.

Description

Multi-hot-spot excitation primary feedback Raman spectrum testing device in liquid environment

Technical Field

The utility model belongs to the technical field of optical sensor towards environmental protection and environmental monitoring, a spectroscopic testing arrangement towards liquid environment, especially trace material detection in environmental water is related to.

Background

The raman spectrum is a scattering spectrum containing information on the vibration and rotation of a substance molecule. Each molecule has its own unique spectral "fingerprint" which can be used to perform chemical identification, compositional analysis, etc. on solid, liquid, and gaseous sample molecules. As a rapid, simple, repeatable and nondestructive quantitative and qualitative analysis tool, the quantitative and qualitative analysis tool is widely applied to the fields of biology, chemistry, physics and the like. The improvement of the detection sensitivity, the repetition rate and the signal to noise ratio of the target object is the core content of related research and device development.

The raman spectrum testing device is generally a single hot spot excitation device, i.e. the output excitation light is focused to one point, and the raman scattering spectrum signals are collected on the original path. But only the interaction between the light at the focus of the exciting light and the sample is utilized, and the utilization rate of the liquid to-be-measured object and the energy of the exciting light is low. The volume or distance of interaction of liquid and exciting light can be obviously enhanced by constructing a plurality of hot spot excitations, so that the intensity and the signal to noise ratio of Raman scattering signals are obviously improved, and online high-sensitivity sample detection is realized. The utility model discloses just based on above-mentioned consideration, propose to introduce raman spectrum testing arrangement with multifocal optical system, increase the number of hotspots, promote raman spectrum testing performance and reach the level that the trace detected. On the basis, a portable Raman spectrum detection instrument with good stability and high sensitivity is developed.

SUMMERY OF THE UTILITY MODEL

The utility model provides a raman spectroscopy testing arrangement that is applicable to liquid environment's many hot spot arouses, former way feedback. The method has the advantages that the multiplication of a feedback mechanism and excitation efficiency is realized by constructing a plurality of Raman spectrum excitation hot spots, the accumulated multiplication of Raman spectra is realized by utilizing multiple focusing of excitation light and original feedback, and the intensity of Raman spectrum signals is obviously enhanced, so that the detection sensitivity of a target object in a liquid substance is improved, and a new technical method is provided for the detection of a solution.

The utility model provides a be suitable for liquid environment's a raman spectroscopy testing arrangement based on many hot spot arouses, former way feedback mechanism, a serial communication port, including a plurality ofThe concave reflector is used for emitting the excitation light to a first concave reflector in the liquid after the excitation light is collimated by optical filtering along the propagation direction of the light path, the reflected light beam forms a first focus, and a distance r is arranged behind the first focus along the light path₁A second concave reflector for reflecting the light beam to form a second focus at a distance r behind the second focus along the light path₂The third concave reflector is arranged behind the first concave reflector, and n concave reflectors are obtained by analogy in sequence; the light reflected by the (n-2) th concave mirror forms an (n-2) th focal point, which is a distance r behind the (n-2) th focal point_n-2The rear part is an n-1 th concave reflector, light reflected by the n-1 th concave reflector forms an n-1 th focal point, and the n-th concave reflector is vertical to an incident light beam; the reflected light from the previous concave mirror is used as the incident light from the next concave mirror.

Preferably, n concave reflectors are arranged in two rows, the concave surfaces of the concave reflectors face the middle of the two rows, and the concave reflectors in the two rows are arranged in a crossed manner; each focus is located between two rows.

The curvature and radius of each concave reflector can be the same or different, and the incident light can be reflected by 100% among the n concave reflectors;

a distance r behind the ith focal point_iThe focal length is 1 time longer than that of the (i + 1) th concave reflector, and i is 1 to n-1;

by adopting the structure, 100% of light reflected by the n-1 th concave reflector can be reflected back in the original path while the last concave reflector, namely the nth concave reflector, takes the light reflected by the n-1 th concave reflector as incident light beams; the excitation light beam is focused for multiple times by the concave reflecting mirror and then fed back in the original path, and 2(n-1) focuses are formed. The intensity of the Raman scattered light signal is 2(n-1) times that of a common single-focus test device. In theory, n may be any natural number. Considering practical situations, n is generally less than 6.

The concave reflector is formed by plating a high-reflectivity film on a concave curved surface, so that high-efficiency reflection and focusing of visible-near infrared light are realized. The reflecting film material can be gold, silver, copper, aluminum and other metal materials, and is a single-layer or multi-layer dielectric film.

During the test, will the device arrange the liquid that awaits measuring in, in incidenting liquid after the optical filtering collimation of excitation light on the concave surface of the first concave surface speculum of device, collect raman scattering spectral signal through the original road, then test.

The utility model has the advantages of:

1) the utility model discloses utilize concave surface speculum to focus exciting light many times, realized that a plurality of hotspots arouse the liquid that awaits measuring simultaneously, add up the raman scattering spectrum that each focus produced to with raman spectrum signal intensity reinforcing multifold.

2) The original feedback realizes that exciting light is reflected by 100 percent, so that the focus of the exciting light is doubled, and the intensity of a Raman spectrum signal is doubled accordingly.

3) The method has the advantages of simple and compact design, no influence on integration miniaturization, strong practicability and no strict requirement on objective conditions.

Drawings

Fig. 1 is a schematic view of the optical path of the "multi-hot-spot excitation original-path feedback" method of the present invention.

① incident excitation beam (solid line), ② reflected excitation beam and raman scattered light (dashed line), ③ concave mirror.

FIG. 2 is a schematic diagram showing the optical path and dimensions of the "multi-hot spot excitation primary feedback" method in example 1;

a. b and c respectively correspond to the first two or three concave reflectors.

Detailed Description

The present invention will be further described with reference to the following examples, but the present invention is not limited to the following examples.

Example 1

The first, second and third concave reflectors have the same size and focal length. The parallel excitation beam is incident, reflected by the first concave mirror and focused on the focus of the first concave mirror. The second concave reflector is at the position twice the focal length behind the first focal point, and the light beam is focused at the position twice the focal length after being reflected by the second concave reflector. The third concave reflector is placed perpendicular to the light beam at the position twice as far as the focal length behind the second focal point, and the light beam returns along the original path after being reflected by the third reflector. The excitation beam is focused 4 times under the reflection of three concave mirrors. The raman scattering spectral signal intensity is enhanced to 4 times.

Claims

1. a multi-hot spot excitation original path feedback Raman spectroscopy test device in a liquid environment, is characterized in that, comprises a plurality of concave mirrors, along the optical path propagation direction, the excitation light is incident on the No. 1 liquid in the liquid after optical filtering and collimation. On a concave mirror, the reflected beam will form the first focal point, and a distance r ₁ behind the first focal point along the optical path will be the second concave mirror, and the reflected beam from the second concave mirror will form the second focal point , a distance r ₂ behind the second focus along the optical path is the third concave mirror, and so on, there are n concave mirrors in total; the light reflected by the n-2th concave mirror will form the n-2th focus , a distance r _n-2 behind the n-2th focus is the n-1th concave mirror, the light reflected by the n-1th concave mirror will form the n-1th focus, and the nth concave reflection The mirror is perpendicular to its incident beam; the light reflected from the previous concave mirror acts as the incident light for the next concave mirror.

2. The multi-hot spot excitation original path feedback Raman spectroscopy testing device in a liquid environment according to claim 1, wherein the n concave mirrors are arranged in two rows, and the concave surface of the concave mirror is toward the middle of the two rows , the two rows of concave mirrors are arranged in a crossed manner; the respective focal points are located between the two rows.

3. The multi-hot spot excitation original path feedback Raman spectroscopy testing device in a liquid environment according to claim 1, wherein the curvature and the radius of each concave mirror are the same or different, and make Incident light can be 100% reflected between n concave mirrors.

4. according to the multi-hot spot excitation original path feedback Raman spectroscopy test device in a kind of liquid environment according to claim 1, it is characterized in that, a distance ri behind the _i -th focus is greater than the i+1 concave mirror. 1x focal length, i is 1 to n-1.

5 . The multi-hot spot excitation original path feedback Raman spectroscopy test device in a liquid environment according to claim 1 , wherein n is less than 6. 6 .

6. The multi-hot spot excitation original path feedback Raman spectroscopic testing device in a liquid environment according to claim 1, characterized in that, adopting the above-mentioned structure in the last concave mirror, that is, the nth concave mirror, The light reflected by n-1 concave mirrors can be used as the incident beam and can also be reflected back 100% in the same way; the concave mirror is used to focus the excitation beam for many times and then the original way is fed back, forming a total of 2(n-1) focal points; The intensity of the Raman scattered light signal is 2(n-1) times that of the single-focus test device.