CN113030004A - Focusing device of self-adaptive terahertz reflection type measuring system - Google Patents
Focusing device of self-adaptive terahertz reflection type measuring system Download PDFInfo
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Abstract
The invention discloses a self-adaptive terahertz reflective measurement system focusing device, which comprises a sample self-adaptive adjusting platform, a sample self-adaptive adjusting control module and a terahertz signal monitoring and processing module, wherein the sample self-adaptive adjusting platform is arranged at the lower sides of a first focusing lens and a second focusing lens and is vertical to the plane where a reflection light path is positioned, the terahertz signal monitoring and processing module is used for acquiring terahertz time-domain spectral signals in real time, determining terahertz reflection peaks corresponding to positions of samples to be detected and sending the intensity of the terahertz reflection peaks to the sample self-adaptive adjusting control module in real time, the sample self-adaptive adjusting control module is connected with the sample self-adaptive adjusting platform, and the device is used for adjusting the sample self-adaptive adjusting table to move up and down according to the received terahertz time-domain spectrum signal until the position of the sample to be detected, which needs to be detected, is located at the focal position of the reflection light path. It changes manual regulation into automatically regulated, has reduced the human cost that operating personnel adjusted, and to a great extent has shortened time cost.
Description
The technical field is as follows:
the invention belongs to the technical field of terahertz spectrum and imaging, and particularly relates to a focusing device of a self-adaptive terahertz reflective measurement system.
Background art:
the terahertz time-domain spectroscopy system (TDS for short) based on the photoconductive antenna is the most mature terahertz spectroscopy and imaging product at present. The terahertz pulse is generated after the femtosecond laser pulse emitted by the femtosecond laser device acts on the photoconductive emission antenna, the terahertz pulse is transmitted in the spatial light path system and passes through a sample, equivalent sampling is realized by carrying sample information through an optical delay line, and then the terahertz pulse is received by the photoconductive detection antenna to obtain a terahertz time-domain spectral signal.
The space optical path system can be divided into a transmission type optical path system and a reflection type optical path system, wherein the information acquired by the transmission type optical path system is generated by the absorption effect of the sample to be detected on the terahertz waves; the information acquired by the reflective optical path system is generated by the reflection effect of the sample to be detected on the terahertz waves; meanwhile, the terahertz wave needs to be precisely focused on the measured sample in an aligned manner so as to obtain a higher terahertz signal carrying sample information. For the transmission optical path system, the focus is the center of the distance between the two middle focusing lenses; for the reflective optical path system, an operator is required to manually adjust the height of the sample stage for focusing.
The manual focusing operation is complicated and not intelligent, and accurate focusing cannot be achieved, so that the terahertz signal intensity is weakened, and the signal is unstable. Under the general condition, some irregular samples, samples with uneven surfaces, samples with uneven thicknesses and the like exist in a detected sample, so that the manual focusing difficulty is greatly improved, larger adjusting errors are introduced, accurate focusing cannot be realized, the optimal reflected signal quality cannot be obtained easily, and the measuring accuracy cannot be ensured. Particularly for the terahertz point-by-point scanning imaging technology, a sample needs to be placed on a two-dimensional scanning translation table, terahertz signals are measured on different areas of the sample by continuously moving the position of the sample, all data are finally integrated together to form a terahertz image of the sample, if accurate focusing cannot be achieved, the measured terahertz signals of all points have errors, the integrated data have larger errors, and the terahertz image of the sample is seriously distorted.
In addition, because of different test requirements of the tested sample, the focus needs to be focused on the upper surface, the lower surface or a middle layer of the tested sample, which makes manual focusing difficult.
The invention content is as follows:
the invention aims to overcome the defects in the prior art, and seeks to design a focusing device of a self-adaptive terahertz reflective measurement system, so that the problem that the terahertz reflective measurement system is difficult to focus is solved, and the height of a sample stage is automatically adjusted according to the form and the test requirement of a sample, so that the optimal reflected signal quality is obtained, and the measurement accuracy is optimized.
In order to achieve the purpose, the invention relates to a focusing device of a self-adaptive terahertz reflective measurement system, which comprises a sample self-adaptive adjusting platform, a sample self-adaptive adjusting control module and a terahertz signal monitoring and processing module, wherein the sample self-adaptive adjusting platform is arranged at the lower sides of a first focusing lens and a second focusing lens and is vertical to the plane of a reflection light path, a sample to be detected is arranged at the top of the sample self-adaptive adjusting platform, the terahertz signal monitoring and processing module is connected with the sample self-adaptive adjusting control module and is used for acquiring terahertz time-domain spectral signals in real time, determining terahertz reflection peaks corresponding to the positions of the sample to be detected and sending the intensity of the terahertz reflection peaks to the sample self-adaptive adjusting control module in real time, the sample self-adaptive adjusting control module is connected with the sample self-adaptive adjusting platform and is used for adjusting the sample self-adaptive adjusting, and the position of the sample to be detected, which needs to be detected, is at the focal position of the reflection light path.
Further, the terahertz signal monitoring and processing module comprises a terahertz reflection peak monitoring module and a terahertz reflection peak intensity extraction module, wherein the terahertz reflection peak monitoring module is used for searching the number of terahertz reflection peaks in the terahertz time-domain spectrum signal acquired in real time and determining the terahertz reflection peak required by corresponding measurement according to the number of the peaks; the terahertz reflection peak intensity extraction module tracks the signal intensity of the terahertz reflection peak in the moving process along with the sample self-adaptive adjustment platform and sends the terahertz reflection peak intensity to the sample self-adaptive adjustment control module in real time, and the terahertz reflection peak intensity extraction module is respectively connected with the terahertz reflection peak monitoring module and the sample self-adaptive adjustment control module.
Further, the sample self-adaptive adjusting platform comprises an objective table, a plunger, a hydraulic cylinder, an oil mass control system, an oil pipe and a base, wherein the plunger on the hydraulic cylinder is connected with the objective table, the bottom of the hydraulic cylinder 1 is fixed on the base, the oil mass control system is connected with the hydraulic cylinder through the oil pipe, a sample self-adaptive adjusting control module is connected with the oil mass control system, and is used for sending a motion instruction to the oil mass control system and adjusting the motion instruction in real time based on the fed-back terahertz time-domain spectrum signal.
Further, the sample self-adaptive adjusting platform is fixed on the two-dimensional scanning translation platform.
Compared with the prior art, the invention has the following beneficial effects:
1. the automatic focusing device of the terahertz reflection type measuring system is provided, manual adjustment is changed into automatic adjustment, the labor cost of adjustment of operators is reduced, and the time cost is greatly reduced;
2. errors introduced by self-adaptive adjustment are far smaller than those introduced by manual adjustment, the high-precision operation of an oil quantity control system can be set, and the motion parameters can be set according to the required signal quality, so that the signal quality of reflection measurement is greatly improved, and the measurement accuracy is optimized;
3. the self-adaptive adjustment adopts an oil quantity control system to drive the pressure oil to enter/exit the hydraulic cylinder so as to drive the objective table to move, and the oil inlet/outlet speed and the oil inlet/outlet quantity of the oil quantity control system can be automatically set, so that the height adjustment is more flexible, more convenient and more intelligent.
Description of the drawings:
fig. 1 is a schematic structural diagram of a focusing device of an adaptive terahertz reflective measurement system according to embodiment 1.
Fig. 2 is a structural diagram of a sample adaptive adjustment unit according to example 1.
FIG. 3 is a schematic diagram of stage movement in the focusing apparatus of the adaptive terahertz reflective measurement system.
Fig. 4 is a diagram of a specific optimization process of the focusing device of the adaptive terahertz reflective measurement system.
The specific implementation mode is as follows:
the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and all other embodiments obtained by a person of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the protection scope of the present invention. The terms "front", "back", "left", "right", "upper", "lower" and the like in the present invention are used for describing the relative relationship between the components, and the terms "first", "second" and the like are used for distinguishing different components and are not limited in the present application.
As shown in fig. 1, the terahertz reflective measurement system generally includes a femtosecond laser 1, a beam splitter 2, an optical oscillation delay line 3, a bias source 4, a terahertz transmitting antenna 5, a terahertz detecting antenna 10, a reflection optical path, a signal generating and collecting processing unit 11, and an upper computer 12. The first collimating lens 6, the first focusing lens 7, the second focusing lens 8 and the second collimating lens 9 constitute a reflection light path, the femtosecond pulse laser generated by the femtosecond laser 1 is split by the beam splitter 2, one beam is pumping light, the other beam is detection light, under the action of the bias source 4, the pumping light is directly focused on the terahertz emitting antenna 5 to generate terahertz pulses, the terahertz pulses sequentially pass through the first collimating lens 6 and the first focusing lens 7 and then irradiate on a sample to be detected, the terahertz pulses carrying the information of the sample to be detected sequentially pass through the second focusing lens 8 and the second collimating lens 9 and then are focused on the terahertz detecting antenna 10 to meet the detection light delayed by the optical oscillation delay line 3 to output photocurrent signals, the photocurrent signals are processed by the signal generating and collecting processing unit 11 and then are sent to the upper computer 12 to obtain terahertz time-domain spectroscopy signals, in the process, the optical oscillation delay line 3 and the bias source 4 are both connected with and controlled by the signal generation and acquisition processing unit 11.
As shown in fig. 1 and 2, the focusing device of the adaptive terahertz reflective measurement system according to this embodiment includes a sample adaptive adjustment stage 13, a sample adaptive adjustment control module 14, and a terahertz signal monitoring processing module 15, wherein the sample adaptive adjustment control module 14 and the terahertz signal monitoring processing module 15 are disposed in the upper computer 1, the sample adaptive adjustment stage 13 is disposed under the first focusing lens 7 and the second focusing lens 8 and perpendicular to the plane where the reflection light path is located, the sample to be measured is disposed on the top of the sample adaptive adjustment stage 13, the terahertz signal monitoring processing module 15 is connected to the sample adaptive adjustment control module 14, the terahertz signal monitoring processing module 15 is configured to obtain a terahertz time-domain spectrum signal in real time, determine a terahertz reflection peak corresponding to a position of the sample to be measured, and send the terahertz reflection peak intensity to the sample adaptive adjustment control module 14 in real time, the sample adaptive adjustment control module 14 is connected to the sample adaptive adjustment stage 13, and is configured to adjust the sample adaptive adjustment stage 13 to move up and down according to the received terahertz time-domain spectrum signal until a position of the sample to be detected is located at a focal position of the reflection light path.
The position of the sample to be detected, which needs to be detected, changes along with the change of the processing requirement. When the terahertz time-domain spectrum analyzer is used for spectrum measurement, the focus of a reflection light path needs to be on the upper surface of a measured sample, only one reflection is needed, and the corresponding terahertz time-domain spectrum shows a single peak. When the terahertz time-domain spectrum terahertz wave source is used for thickness measurement, the focus of a reflection light path needs to be on the lower surface of a sample, and the corresponding terahertz time-domain spectrum can form double peaks or even multiple peaks when light passes through the sample and reaches the lower surface. When point-by-point scanning imaging is carried out, the terahertz data acquisition is carried out on different positions by continuously moving the sample. Therefore, the terahertz signal monitoring processing module 15 comprises a terahertz reflection peak monitoring module 1501 and a terahertz reflection peak intensity extraction module 1502, wherein the terahertz reflection peak monitoring module 1501 is used for searching the number of terahertz reflection peaks in the terahertz time-domain spectrum signal acquired in real time and determining the terahertz reflection peak required by corresponding measurement according to the number of the peaks; the terahertz reflection peak intensity extraction module 1502 tracks the signal intensity of the terahertz reflection peak in the process of moving along with the sample adaptive adjustment table 13, and sends the terahertz reflection peak intensity to the sample adaptive adjustment control module 14 in real time, and the terahertz reflection peak intensity extraction module 1502 is respectively connected with the terahertz reflection peak monitoring module 1501 and the sample adaptive adjustment control module 14.
As shown in fig. 3, the sample adaptive adjustment stage 13 includes an object stage 1301, a plunger 1302, a hydraulic cylinder 1303, an oil amount control system 1304, an oil pipe 1305 and a base 1306, the plunger 1302 on the hydraulic cylinder 1303 is connected to the object stage 1301, the bottom of the hydraulic cylinder 1303 is fixed to the base 1306, the oil amount control system 1304 is connected to the hydraulic cylinder 1303 through the oil pipe 1305, and the sample adaptive adjustment control module 14 is connected to the oil amount control system 1304, and sends a movement instruction to the oil amount control system 1304 and adjusts the movement instruction in real time based on a fed-back terahertz time-domain spectrum signal.
Further, the sample adaptive adjustment stage 13 is fixed on the two-dimensional scanning translation stage, and movement along the X axis and the Y axis is realized.
Specifically, the sample adaptive adjustment control module 14 sends a motion instruction to control the adjustment sample adaptive adjustment stage 13 to ascend (or descend), the motion instruction is not changed when the terahertz reflection peak signal becomes optimal, the motion instruction is reversely adjusted when the terahertz reflection peak signal is monitored to be deteriorated, and a motion stop instruction is sent when the optimal terahertz reflection peak signal in the forward motion process is obtained in the reverse motion process. The movement instruction comprises ascending, descending and stopping, the movement parameters corresponding to the ascending are oil inlet speed, maximum oil inlet amount and the like, the movement parameters corresponding to the descending are oil outlet speed, maximum oil outlet amount and the like, the movement parameters corresponding to the stopping are oil outlet speed 0, the oil inlet speed and the maximum oil inlet amount correspond to the ascending speed and range of the plunger, and the oil outlet speed and the maximum oil outlet amount correspond to the descending speed and range of the plunger. If the oil quantity control system 1304 receives a rising instruction, pressing oil into the hydraulic cylinder through the oil pipe according to the set oil inlet rate and the maximum oil inlet quantity, wherein the hydraulic cylinder drives the plunger to move upwards, and the plunger drives the objective table to move upwards; after the oil quantity control system 1304 receives the descending movement instruction, the pressurized oil is discharged from the hydraulic cylinder through the oil pipe according to the set oil inlet speed and the maximum oil inlet quantity, and the plunger descends to drive the objective table to move downwards.
As shown in fig. 4, the specific optimization process of the focusing device of the adaptive terahertz reflective measurement system includes:
(1) in the case where no oil is fed, the sample stage 13 is in a natural height state (i.e., the lowest position), and the sample stage 13 is placed below and horizontal to the first focusing lens 7 and the second focusing lens 8, and this position is denoted as L0. The stage is at a distance of at least one focal length (i.e., focal length f of the focusing lens) from the two focusing lenses.
(2) Setting a first motion parameter in a sample adaptive adjustment control module 14 in the upper computer 4 in advance, wherein the first motion parameter can be set as oil inlet first and oil outlet later, the oil inlet/outlet rate a1, and the maximum oil inlet/outlet amount c1 (corresponding to the maximum distance d1), so that in the range of L0+ d1, the oil quantity control system moves at the oil inlet speed of a1, the plunger moves upwards at a constant speed, when the signal becomes optimal, the oil is continuously fed, the plunger continues to move upwards, when the signal becomes poor, the oil quantity control system moves at the oil outlet speed of a1, the plunger moves downwards at a constant speed, and when the first terahertz signal is strongest, the first motion parameter stops;
(3) a second motion parameter is set in the sample adaptive adjustment control module 14 in the upper computer 4, and the second motion parameter may be oil inlet first and oil outlet later (or oil inlet first and oil outlet later), an oil inlet/outlet rate a2, and a maximum oil inlet/outlet amount c2 (corresponding to the maximum distance d2), so that in the range of L1 ± d2, the oil amount control system will use oil inlet (or oil outlet) of a2, the plunger will move upward (or downward) at a constant speed, when the signal becomes optimal, oil inlet (or oil outlet) will continue, the plunger will continue to move upward (or downward), when the signal becomes poor, the oil amount control system will move at an oil outlet (or oil inlet) speed of a2, the plunger will move downward (or upward) at a constant speed, and when the second terahertz signal is strongest, the plunger stops. In order to realize the further accurate adjustment of the position of the sample to be detected, the first motion parameter and the second motion parameter need to satisfy a1> a2, c1> c2 (namely d1> d 2). Similarly, in order to improve the adjustment precision, a third motion parameter or more motion parameters can be additionally set in combination with the actual situation.
Example 1
The self-adaptive terahertz reflection type measuring system focusing device is used for performing spectral measurement on rough-surface samples and irregular samples with uneven thickness, and specifically comprises the following steps:
(1) a sample to be detected is placed on an objective table, the focus of a reflection light path is aligned to a certain position of the sample to be detected, a single peak appears in a terahertz time-domain spectral signal monitored by a terahertz reflection peak monitoring module 1501, namely the terahertz reflection peak to be monitored, when spectral measurement is carried out, the focus of the reflection light path needs to be on the upper surface of the sample to be detected, only one reflection is carried out, and therefore the terahertz signal can appear a single peak;
(2) the sample adaptive adjustment control module 14 controls the sample adaptive adjustment stage 13 to move according to a first motion parameter, which is set as oil inlet first and oil outlet later, an oil inlet/outlet rate a1, a maximum oil inlet/outlet amount c1 (corresponding to a maximum distance d1), in the range of L0+ d1, the oil amount control system will move at the oil inlet speed of a1, the plunger will move upward at a constant speed, the terahertz reflection peak intensity extraction module 1502 tracks the terahertz time-domain spectrum signal intensity of the terahertz reflection peak in the process of moving along with the sample adaptive adjustment stage 13, feeding the terahertz time-domain spectral signal intensity back to the sample adaptive adjustment control module 14, if the signal becomes optimal, continuing to feed oil, if the signal becomes optimal, continuing to move the plunger upwards, if the signal becomes poor, moving the oil quantity control system at the oil outlet speed of a1, and if the plunger moves downwards at a constant speed, stopping when the first terahertz signal is strongest;
(3) the sample adaptive adjustment control module 14 controls the sample adaptive adjustment table 13 to move according to a second motion parameter, the second motion parameter is set as oil inlet first and oil outlet later, the oil inlet/outlet rate a2, and the maximum oil inlet/outlet amount c2 (corresponding to the maximum distance d2), then within the range of L1 ± d2, the oil amount control system takes oil inlet of a2, the plunger moves upward at a constant speed, the terahertz reflection peak intensity extraction module 1502 tracks the terahertz time-domain spectral signal intensity during the movement of the terahertz reflection peak along with the sample adaptive adjustment table 13, and feeds back the terahertz time-domain spectral signal intensity to the sample adaptive adjustment control module 14, if the signal becomes better, the oil inlet continues to move, if the signal becomes worse, the oil amount control system moves at an oil outlet speed of a2 at a constant speed, the plunger moves downward, and the second terahertz signal stops when the second terahertz signal is strongest, at this time, an optimal reflection signal is obtained, that is, the focal point of the reflection optical path is precisely focused on the upper surface of the sample, so that the terahertz signal at the point can be accurately obtained.
Example 2
The method for measuring the thickness of the rough surface sample and the irregular single-layer sample with uneven thickness by adopting the self-adaptive terahertz reflection type measuring system focusing device specifically comprises the following steps:
(1) when a single-layer sample is not placed on the object stage, the sample adaptive adjustment control module 14 controls the sample adaptive adjustment table 13 to move from top to bottom (or from bottom to top), the terahertz reflection peak monitoring module 1501 monitors a single peak in the terahertz time-domain spectral signal, namely the terahertz reflection peak to be monitored, the focus of the reflection light path needs to be on the upper surface of the object stage, and only one reflection is carried out, so that the terahertz signal has a single peak;
(2) the sample adaptive adjustment control module 14 controls the sample adaptive adjustment stage 13 to move sequentially according to the first motion parameter and the second motion parameter, and adjusts the sample adaptive adjustment stage according to the steps described in embodiment 1 to obtain an optimal reflection signal, that is, a focal point of a reflection optical path is accurately focused on the upper surface of the object stage, so that a terahertz signal when a sample is not placed can be accurately obtained;
(3) on the basis of the step (2), a single-layer sample to be measured is placed on an objective table, the focus of a reflection light path is aligned to a certain position of the sample to be measured, the focus of the reflection light path needs to be on the lower surface of the sample when thickness measurement is carried out, and double peaks can be formed when light passes through the sample and reaches the lower surface; the terahertz reflection peak monitoring module 1501 monitors double peaks in the terahertz time-domain spectral signal, and uses a stronger reflection peak as a main monitoring object and the other reflection peak as a secondary monitoring object;
(4) resetting the first motion parameter and the second motion parameter, controlling the sample adaptive adjustment platform 13 to move sequentially according to the first motion parameter and the second motion parameter by the sample adaptive adjustment control module 14, finely adjusting the height of the placed sample, adjusting according to the steps described in embodiment 1, and simultaneously considering the dual-peak signal intensity to obtain the best reflection signal, i.e. accurately focusing the focus of the reflection light path on the lower surface of the sample, so as to accurately obtain the terahertz signal passing through the single-layer sample.
Example 3
The method for measuring the thickness of the irregular multilayer sample with rough surface and uneven thickness by adopting the focusing device of the self-adaptive terahertz reflection type measuring system comprises the following steps:
(1) adjusting the stage on which the multilayer sample is not placed to an optimal height according to the steps (1) to (2) described in example 2;
(2) placing a multilayer sample to be detected on an objective table, and aligning the focus of a reflection light path to a certain position of the sample to be detected; when the thickness is measured, the focus of the reflection light path needs to be on the lower surface of the sample, and multiple peaks can be formed in the process that light rays pass through the multiple layers of samples to reach the lower surface; the terahertz reflection peak monitoring module 1501 monitors that N +1 peaks appear in the terahertz time-domain spectral signal and serve as a plurality of reflection peaks of a multilayer sample, wherein N is the number of layers of the sample, a stronger reflection peak serves as a main monitoring object, and the rest reflection peaks serve as secondary monitoring objects;
(3) resetting the first motion parameter and the second motion parameter, controlling the sample adaptive adjustment stage 13 to move from top to bottom by the sample adaptive adjustment control module 14, fine-tuning the height after the sample is placed, adjusting according to the steps described in embodiment 1, and simultaneously considering the multi-peak signal intensity to obtain the optimal reflection signal, i.e. accurately focusing the focus of the reflection optical path on the lower surface of the sample on the nth layer, so as to accurately obtain the terahertz signal passing through the multilayer sample.
Example 4
The method for terahertz point-by-point scanning imaging of the irregular sample with rough surface and uneven thickness by adopting the focusing device of the adaptive terahertz reflection type measurement system in the embodiment 1 generally needs to adjust a focus to the lower surface of the sample, and specifically comprises the following steps:
(1) adjusting the stage on which the sample to be measured is not placed to the optimal height according to the steps (1) to (2) in the embodiment 2;
(2) placing a sample to be measured on an object stage, repeating the steps (3) - (4) in the embodiment 2 or the steps (2) - (3) in the embodiment 3 according to the type of the sample, and obtaining an optimal reflection signal, namely, accurately focusing the focus of a reflection optical path on the lower surface of the sample to be measured so as to accurately obtain a terahertz signal at the point;
(3) and (3) moving the sample self-adaptive adjusting table 13 along the X axis or the Y axis of the two-dimensional scanning translation table according to a certain rule, repeating the step (2), completing point-by-point scanning of the sample to be detected until the terahertz signal acquisition of the whole sample is completed, and then reconstructing three-dimensional information to form the terahertz image of the sample. If the thickness of the sample is not uniform, the surface is rough, or the sample is irregular, the terahertz signal of each point is not optimal when the sample is scanned point by point, and the measurement result is distorted. By adopting the method, the terahertz signal is always in the optimum state so as to obtain the optimum terahertz image.
Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes in the embodiments and/or modifications of the invention can be made, and equivalents and modifications of some features of the invention can be made without departing from the spirit and scope of the invention.
Claims (4)
1. A self-adaptive terahertz reflection type measuring system focusing device is characterized by comprising a sample self-adaptive adjusting platform, a sample self-adaptive adjusting control module and a terahertz signal monitoring and processing module, wherein the sample self-adaptive adjusting platform is arranged on the lower sides of a first focusing lens and a second focusing lens and is vertical to the plane where a reflection light path is located, a sample to be measured is arranged on the top of the sample self-adaptive adjusting platform, the terahertz signal monitoring and processing module is connected with the sample self-adaptive adjusting control module and is used for acquiring terahertz time-domain spectral signals in real time, determining terahertz reflection peaks corresponding to the positions of the sample to be measured, and sending the intensity of the terahertz reflection peaks to the sample self-adaptive adjusting control module in real time, the sample self-adaptive adjusting control module is connected with the sample self-adaptive adjusting platform and is used for adjusting the sample self-adaptive adjusting platform to move up and, and the position of the sample to be detected, which needs to be detected, is at the focal position of the reflection light path.
2. The focusing device for the adaptive terahertz reflective measurement system according to claim 1, wherein the terahertz signal monitoring and processing module comprises a terahertz reflection peak monitoring module and a terahertz reflection peak intensity extraction module, the terahertz reflection peak monitoring module is configured to search the number of terahertz reflection peaks in the terahertz time-domain spectrum signal acquired in real time, and determine the terahertz reflection peak required for the corresponding measurement according to the number of peaks; the terahertz reflection peak intensity extraction module tracks the signal intensity of the terahertz reflection peak in the moving process along with the sample self-adaptive adjustment platform and sends the terahertz reflection peak intensity to the sample self-adaptive adjustment control module in real time, and the terahertz reflection peak intensity extraction module is respectively connected with the terahertz reflection peak monitoring module and the sample self-adaptive adjustment control module.
3. The focusing device of the adaptive terahertz reflective measuring system according to claim 2, wherein the sample adaptive adjusting platform comprises an object stage, a plunger, a hydraulic cylinder, an oil quantity control system, an oil pipe and a base, the plunger on the hydraulic cylinder is connected with the object stage, the bottom of the hydraulic cylinder 1 is fixed on the base, the oil quantity control system is connected with the hydraulic cylinder through the oil pipe, and the sample adaptive adjusting control module is connected with the oil quantity control system, sends a motion instruction to the oil quantity control system and adjusts the motion instruction in real time based on the fed-back terahertz time-domain spectrum signal.
4. The adaptive terahertz reflective measurement system focusing device of claim 3, wherein the sample adaptive adjustment stage is fixed on a two-dimensional scanning translation stage.
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Application publication date: 20210625 |