CN103471716B - Interface full-spectrum imaging analytical instrument system - Google Patents

Abstract

The invention discloses an interface full-spectrum imaging analysis instrument system, which includes a laser light source control module, a positioning platform module, an interface full-spectrum signal light-splitting module, an interface full-spectrum signal acquisition and detection module, and a host computer; the system is highly integrated and applicable Strong and multi-functional system, it can obtain quasi-interface infrared, Raman and sum-frequency optical signals at the same time. Through this system, the quasi-interface infrared, Raman and sum-frequency optical signals can be converted into electrical signals at the same time, and processed by the host computer The spectral information and three-dimensional images of the three are obtained, and the physical and chemical information such as molecular structure, orientation, adsorption and thermodynamics are revealed in detail.

Description

An interface full-spectrum imaging analysis instrument system

technical field

The invention relates to an interface full-spectrum imaging analysis instrument system.

Background technique

The interface of matter is the area of separation and transition between phases, and the scientific research related to the interface of matter is collectively referred to as interface science. The interface layer is generally composed of one or several molecular (or atomic) layers. Due to the different properties of the phases, the physical and chemical properties of the interface molecules (or atoms) are the same as those of the molecules (or atoms) in the separated two phases. Are not the same. It is the special properties of these interface molecules (or atoms) that endow the interface with special functions and the challenges of interface science research.

The acquisition of information such as the physical and chemical properties of interfaces is the basis of interface science research. The acquisition of these information is based on the understanding of the interface microstructure information. However, accurate acquisition of interface structure information is very difficult. Compared with the ontology of the research object, the particularity of the interface mainly lies in its sensitivity and selectivity. There are many methods for structural analysis, but there are very few characterization methods suitable for interface research. At present, the characterization methods of single phase structure mainly include: electron spectroscopy technology, near-field detection technology, high-energy ray technology, etc. For most research objects, the amount of interface information detected by the existing characterization techniques is very small compared with the ontology, so it is necessary to distinguish the contribution of the interface and the ontology in the process of data processing, which must be done through complex calculations and analysis In order to obtain the information of interface molecules. Therefore, the above-mentioned structural characterization methods do not have the property of interface selection.

For most interface studies, on the basis of obtaining interface structure information, it is more valuable to further monitor the physical and chemical changes that occur at the interface, that is to say, interface dynamics and thermodynamics research is more scientifically attractive , the scientific problems that can be solved are also more critical. Therefore, the ability to study interface structures is a higher-level requirement for detection methods in addition to interface selectivity, and it also has more scientific value and practical significance. Therefore, the research and development of detection instruments and methods with interface selectivity is an important practical demand in the field of interface science research.

With the advancement of optical technology, especially laser technology, linear optical methods and nonlinear optical methods such as infrared spectroscopy and Raman spectroscopy have been greatly developed. Different from other structural analysis methods, the optical method has the advantages of in-situ detection and no damage to the material itself of the research system, which can better meet the needs of interface research. However, since interface molecules have only one or a few molecular layers, strictly speaking, for macroscopic research objects, linear optical methods such as infrared and Raman spectroscopy mainly obtain bulk information or "quasi-interface" information. The second-order nonlinear optical method developed in recent years, such as the sum-frequency spectroscopy method, solves the problem of interface/bulk signal separation in principle, and has unique interface selectivity and interface monolayer sensitivity, which can be used in laser equipment With the cooperation, the information of the interface monolayer can be obtained, which greatly exceeds the existing interface research methods in terms of accuracy.

In the process of sum-frequency spectrum analysis, two incident lasers, usually tunable infrared light and visible light, generate three optical signals after the interface overlaps, one of which is a nonlinear sum-frequency optical signal, and the other two are interface reflections. visible light and infrared light signals. Based on the principle of sum-frequency light generation, it can be determined that the reflected visible light, infrared light and sum-frequency light originate from the same location. So far, in the process of collecting and processing the sum-frequency optical signal, the visible light and infrared light reflected at the same position on the interface are filtered as noise. However, if these signals are collected at the same time, it will be possible to combine the characteristics of linear and nonlinear spectral analysis to obtain complementary information at the same position and time of the interface (quasi-interface), which is more conducive to judging the physical and chemical properties and changing laws of the research object. Similar to total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and conventional Raman spectroscopy, collecting the infrared spectrum and visible spectrum (Raman spectrum) in the reflection direction can obtain the information of "quasi-interface". Compared with light only responding to interface structure information, infrared and Raman spectroscopy can provide structure information at different interface depths at the same position. The development of full-spectrum analysis on the basis of sum-frequency spectrum analysis is not only a synthesis of information, but also provides an innovative comparative research method of interface-quasi-interface. Therefore, taking the generation of the sum-frequency optical signal as the basis for judgment, full-spectrum analysis (infrared and Raman spectroscopy) at the same time and at the same position can be realized in the true sense.

However, the current sum-frequency spectrum detection technology and detection instruments are not yet mature, and the use is relatively complicated, time-consuming and labor-intensive. In terms of comprehensive comparison on a global scale, the level of instrument research and application cannot meet the objective needs of basic research in interface science at all, and can only achieve single-spectrum testing.

Contents of the invention

The invention provides an interface full-spectrum imaging analysis instrument system, which aims to overcome the prior art that can only test a single spectrum of the interface, and at the same time provide the full-spectrum information of the interface at the same position.

An interface full-spectrum imaging analysis instrument system, including a laser light source control module, a positioning platform module, an interface full-spectrum signal splitting module, an interface full-spectrum signal acquisition and detection module, and a host computer;

The laser light source control module is controlled by the host computer;

The interface full-spectrum signal spectroscopic module includes a primary spectroscopic unit and a secondary spectroscopic unit, the primary spectroscopic unit includes a light-condensing sheet group and a reflective grating, and the secondary spectroscopic unit includes components for Raman light, infrared light and A filter set for filtering with frequency light, as well as a secondary grating and amplifying film set;

The laser light source control module is used to generate visible laser and infrared laser with adjustable frequency. After the two lasers intersect and reflect on the interface fixed on the positioning platform module, they reach the reflective grating through the light-condensing sheet group, and the reflective grating outputs The reflected light passes through the filter group of Raman light and infrared light and the amplifier group of sum-frequency light to output optical signals to the interface full-spectrum signal acquisition and detection module; the interface full-spectrum signal acquisition and detection module communicates with the host computer ;

The positioning platform module is fixed below the interface, and the micro-motion control platform in the prior art is used to electrically control the interface in the three directions of x, y and z;

The interface full-spectrum signal acquisition and detection module includes a CCD array unit, a CCD front-end amplifier, an ADC acquisition unit, an ADC control processing unit, a processor, and a clock drive unit. The CCD array unit includes three CCD arrays, three CCD arrays Respectively set opposite to the filter groups of Raman light, infrared light and sum frequency light, the CCD array, CCD front-end amplifier, ADC acquisition unit, ADC control processing unit and processor are connected in sequence, and the clock drive unit is connected to the CCD The arrays are connected, the clock driving unit is controlled by the processor, and the processor is connected to the host computer.

The laser light source control module is a laser controller in the prior art, its near-infrared fundamental frequency energy output stability is less than 3%; the laser frequency modulation system outputs visible light laser spectrum with a resolution of less than 6cm ^-1 , a stability of less than 10%, and a polarization For linear polarization, the degree of polarization can be selected to be >1:100; the difference frequency generator outputs far-infrared laser spectrum with a resolution of less than 6cm ^-1 and a stability of less than 10%.

The closed-loop control resolution of the driving controller in the positioning platform module is ≤1 μm, and the precision is ≤5 μm.

The grating density of the reflective grating in the primary spectroscopic unit is 1200 lines/mm, the wavelength range is 355nm-10μm, the resolution is 0.1nm, the curvature radius is 199.99nm, and the line dispersion rate is 2.08nm/mm.

The processor of the interface full-spectrum signal acquisition and detection module adopts FPGA processor, the CCD array pixels are greater than 2048, the spectral range is 200nm-10μm, the quantum efficiency is greater than 70%, and the signal-to-noise ratio is greater than 2000:1.

Beneficial effect

The invention provides an interface full-spectrum imaging analysis instrument system, including a laser light source control module, a positioning platform module, an interface full-spectrum signal splitting module, an interface full-spectrum signal acquisition and detection module, and a host computer; the system is highly integrated and applicable Strong and multi-functional system, it can obtain quasi-interface infrared, Raman and sum-frequency optical signals at the same time. Through this system, the quasi-interface infrared, Raman and sum-frequency optical signals can be converted into electrical signals at the same time, and processed by the host computer The spectral information and three-dimensional images of the three are obtained, and the physical and chemical information such as molecular structure, orientation, adsorption and thermodynamics are revealed in detail.

Description of drawings

Figure 1 is a schematic diagram of the system structure of the interface full-spectrum imaging analysis instrument;

Fig. 2 is a schematic diagram of an interface full-spectrum signal spectroscopic detection module;

Fig. 3 is a control structure diagram of the CCD array in the interface full-spectrum signal acquisition and detection module.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

The full-spectrum technology is adopted, and the interface full-spectrum imaging analysis instrument system provided by the invention is used to detect and analyze the change of the microstructure and composition of the electrode process interface in situ.

As shown in Figure 1, it is a schematic structural diagram of the interface full-spectrum imaging analysis instrument system of the present invention, including a laser light source control module, a positioning platform module, an interface full-spectrum signal splitting module, an interface full-spectrum signal acquisition and detection module, and a host computer;

The laser light source control module is controlled by the host computer;

As shown in Figure 2, the interface full-spectrum signal light-splitting module includes a primary light-splitting unit and a secondary light-splitting unit, and the primary light-splitting unit includes a light-condensing sheet group and a reflective grating. The first-level light splitting unit includes a filter group for filtering Raman light, infrared light and sum frequency light, as well as a secondary grating and amplifying film group;

The laser light source control module is used to generate visible laser and infrared laser with adjustable frequency. After the two lasers intersect and reflect on the interface fixed on the positioning platform module, they reach the reflective grating through the light-condensing sheet group, and the reflective grating outputs The reflected light passes through the filter group of Raman light and infrared light and the amplifier group of sum-frequency light to output optical signals to the interface full-spectrum signal acquisition and detection module; the interface full-spectrum signal acquisition and detection module communicates with the host computer ;

The positioning platform module is fixed below the interface, and the micro-motion control platform in the prior art is used to electrically control the interface in the three directions of x, y and z;

As shown in Figure 3, the interface full-spectrum signal acquisition and detection module includes a CCD array unit, a CCD front-end amplifier, an ADC acquisition unit, an ADC control processing unit, a processor, and a clock drive unit, and the CCD array unit includes three CCD Array, three CCD arrays are set opposite to the filter groups of Raman light, infrared light and sum frequency light respectively, and the CCD array, CCD front-end amplifier, ADC acquisition unit, ADC control processing unit and processor are connected in sequence, so The clock driving unit is connected with the CCD array, the clock driving unit is controlled by the processor, and the processor is connected with the host computer.

The laser light source control module is a laser controller in the prior art, its near-infrared fundamental frequency energy output stability is less than 3%; the laser frequency modulation system outputs visible light laser spectrum with a resolution of less than 6cm ^-1 , a stability of less than 10%, and a polarization For linear polarization, the degree of polarization can be selected to be >1:100; the difference frequency generator outputs far-infrared laser spectrum with a resolution of less than 6cm ^-1 and a stability of less than 10%. This module can realize the temperature monitoring and control of the laser tube, power monitoring and control, pulse frequency modulation and other functions as a light source control circuit, and realize the stability of the output wavelength of the laser tube, the stability of the output power and various subsequent laser modulation methods. .

As the general controller of the lower computer system, FPGA provides driving timing signals for CCD. CCD collects corresponding spectral signals according to the timing commands of FPGA, amplifies the signals through CCD front-end amplifiers, and ADC (analog-to-digital converter) collects the signals amplified by CCD amplifiers. Spectral information, and the signal is processed in the ADC control processing module, and the FPGA receives the data signal processed by the ADC, converts the data signal into an LVDS (low voltage differential signal) signal and transmits it. In addition, FPGA communicates with the host computer through RS-422 (the electrical characteristics of the balanced voltage digital interface circuit). In this system, the PC is used as the upper computer, and its interface with the lower computer is mainly RS-422 control command interface and LVDS data transmission interface. The image data of the lower computer system is transmitted to the PC through the LVDS image acquisition card, and the library function provided by the acquisition card is used on the PC to perform image acquisition and display processing in the VC6.0 environment to generate color pictures. The PC sends control commands to the lower computer system through the RS-422 interface to set the operating parameters and control modes required by the lower computer system.

The closed-loop control resolution of the drive controller in the positioning platform module is ≤1 μm, and the precision is ≤5 μm. By adjusting the position of the interface, the coordinated control requirements for the input light and receiving optical path of the laser light source control module, sample position, and imaging sensor are met. .

The grating density of the reflective grating in the primary spectroscopic unit is 1200 lines/mm, the wavelength range is 355nm-10μm, the resolution is 0.1nm, the curvature radius is 199.99nm, and the line dispersion rate is 2.08nm/mm.

The processor of the interface full-spectrum signal acquisition and detection module adopts FPGA processor, the CCD array pixels are greater than 2048, the spectral range is 200nm-10μm, the quantum efficiency is greater than 70%, and the signal-to-noise ratio is greater than 2000:1.

Using this system, XRD, XPS, SEM and other analysis methods are used as auxiliary research methods to realize the mutual evidence of in-situ and offline, interface and ontology experimental information.

Claims (5)

1. the full spectral imaging analysis instrument system in interface, is characterized in that, comprises LASER Light Source control module, locating platform module, interface full spectral signal spectral module, the full spectroscopic acquisition in interface and detection module and host computer;

Described LASER Light Source control module is controlled by host computer;

Described interface full spectral signal spectral module comprises elementary spectrophotometric unit and secondary spectrophotometric unit, described elementary spectrophotometric unit comprises concentration piece group and reflection grating, described secondary spectrophotometric unit comprise be respectively used to Raman light, infrared light and and the frequently filter set that filters of light, and secondary grating and macrophotograph group;

Described LASER Light Source control module is for generation of the infrared laser of visible laser and frequency-adjustable, two-way laser is after being fixed on crossing on the interface in locating platform module and reflection, arrive reflection grating through concentration piece group again, the reflected light that reflection grating exports respectively through Raman light and infrared light filter set and and the macrophotograph group output optical signal of light frequently to the full spectroscopic acquisition in interface and detection module; The full spectroscopic acquisition in interface and detection module and host computer communicate to connect;

Described locating platform module is fixed on below interface, adopts fine motion parametric controller of the prior art, and Electronic control is carried out to interface in x, y and z tri-directions;

The full spectroscopic acquisition in described interface and detection module comprise ccd array unit, CCD front-end amplifier, ADC collecting unit, ADC controlled processing unit, processor and clock driver cell, described ccd array unit comprises three ccd array, three ccd array respectively with Raman light, infrared light and and the filter set of frequently light be oppositely arranged, described ccd array, CCD front-end amplifier, ADC collecting unit, ADC controlled processing unit and processor are connected successively, described clock driver cell is connected with ccd array, clock driver cell is controlled by processor, processor is connected with host computer.

2. the full spectral imaging analysis instrument system in interface according to claim 1, is characterized in that, described LASER Light Source control module is laser controller of the prior art, and its near infrared fundamental frequency energy output stability is less than 3%; Laser frequency-modulation system exports visible light lasers spectral resolution and is less than 6cm ^-1, stability is less than 10%, and polarization is linear polarization, can select degree of polarization >1:100; Difference frequency generator exports Far Infrared resolution and is less than 6cm ^-1, stability is less than 10%.

3. the full spectral imaging analysis instrument system in interface according to claim 1, is characterized in that, closed-loop control resolution≤1 μm of the driving governor in described locating platform module, precision≤5 μm.

4. the full spectral imaging analysis instrument system in interface according to claim 1, is characterized in that, the raster density of the reflection grating in described elementary spectrophotometric unit is 1200 lines/mm, wavelength coverage 355nm-10 μm, resolution 0.1nm, radius-of-curvature 199.99nm, linear dispersion 2.08nm/mm.

5. the full spectral imaging analysis instrument system in the interface according to any one of claim 1-4, it is characterized in that, the processor of the full spectroscopic acquisition in described interface and detection module adopts FPGA processor, ccd array pixel is greater than 2048, spectral range 200nm-10 μm, quantum efficiency is greater than 70%, and signal to noise ratio (S/N ratio) is greater than 2000:1.