A terahertz time-domain spectrometer rapid optical path compensation device

Abstract

The application discloses a kind of terahertz time-domain spectrometer fast optical path compensation device, including light source device, transmitting component and receiving component, transmitting light path is equipped between light source device and transmitting component, receiving light path is equipped between light source device and receiving component, still include reciprocating motion's moving platform, transmitting end transmission component and receiving end transmission component;Transmitting end transmission component and receiving end transmission component all include oppositely arranged mirror group and back mirror group and the connecting light path of connecting mirror group and back mirror group, back mirror group is set on moving platform;The connecting light path in transmitting end transmission component is connected into transmitting light path;The connecting light path in receiving end transmission component is connected into receiving light path;Moving platform reciprocating motion, drive back mirror group movement relative to mirror group, adjust the optical path difference between transmitting light path and receiving light path.The application can quickly adjust the optical path difference of transmitting light path and receiving light path, shorten the time required for optical path compensation, improve scanning speed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of terahertz time-domain spectrometer, more particularly, to a fast optical path compensation device of terahertz time-domain spectrometer. BACKGROUND

[0002] Terahertz time-domain spectroscopy (THz-TDS) is a new emerging spectroscopy technique, and is a research hotspot in the field of terahertz. In a terahertz time-domain spectrometer, a femtosecond laser is emitted by a laser, and is divided into two beams after a beam splitter, one of which is used as pump light, and the other is used as probe light. The pump light is transmitted to a transmitting antenna through an optical fiber, and terahertz waves are generated under the action of a bias voltage. The information of a sample to be measured carried by the terahertz waves after transmission and / or reflection is received by a terahertz detector, and the physical information of the sample can be obtained through wave spectrum analysis technology. The detection result of the sample is obtained by measuring the optical path difference of the pump light and the probe light at different times passing through the sample.

[0003] At present, a terahertz time-domain spectrometer includes multiple modules, such as a transmission module, a reflection module, a transmission imaging module, a polarization module, and a heating module. The optical path designed in each module is different, and module switching is required when different samples are tested or different modes are switched. Therefore, the optical path in the spectrometer needs to be compensated so that the optical path of the pump light and the probe light at the receiving antenna position is equal. The prior art usually uses multiple mirror groups at the transmitting end, and the optical path is bent by 180 degrees through multiple reflections of the multiple mirrors. A motor drives the movement of the mirrors, changes the optical path difference, and achieves the purpose of compensating the change of the optical path. However, the optical path difference of different modules is quite different, and a long time is required for the motor to move after module switching, complete optical path compensation, and the like. SUMMARY

[0004] The present application aims to overcome at least one of the above-mentioned defects of the prior art, and provides a fast optical path compensation device of terahertz time-domain spectrometer, which is used to solve the problem of long time required for optical path compensation of the terahertz time-domain spectrometer.

[0005] The technical scheme adopted by the present application is a kind of fast optical path compensation device of terahertz time-domain spectrometer, including light source device, transmitting assembly and receiving assembly, transmitting light path is connected between the light source device and transmitting assembly, receiving light path is connected between the light source device and receiving assembly, further including reciprocating motion moving platform, transmitting end transmission component and receiving end transmission component;The transmitting end transmission component and the receiving end transmission component all include oppositely arranged mirror group and back mirror group and the connecting light path connecting the mirror group and the back mirror group, the back mirror group is arranged on the moving platform;The connecting light path in the transmitting end transmission component is connected to the transmitting light path;The connecting light path in the receiving end transmission component is connected to the receiving light path;The moving platform reciprocating motion drives the back mirror group to move relative to the mirror group, adjusts the optical path difference between the transmitting light path and the receiving light path.

[0006] The light source device is used for emitting laser. The transmitting assembly is used for converting laser into terahertz signal to emit to the sample to be measured. The transmitting light path is the light path of pump light. The receiving light path is the light path of probe light. The receiving assembly is used for receiving terahertz signal carrying information of the sample to be measured. The moving platform is used for carrying the back mirror group and driving the back mirror group to move relative to the mirror group. The transmitting end transmission component is used for adjusting the optical path of the transmitting light path, and the receiving end transmission component is used for adjusting the optical path of the receiving light path.

[0007] Compared with adjusting the transmitting light path or the receiving light path alone, in the present technical scheme, a single stroke of the moving platform can change the distance between the back mirror group and the mirror group in the transmitting end transmission component and the receiving end transmission component, so as to simultaneously adjust the transmitting light path and the receiving light path and compensate the optical path. Specifically, the distance between the mirror group and the back mirror group in the transmitting end transmission component is reduced, the distance between the mirror group and the back mirror group in the receiving end transmission component is increased, the optical path of the transmitting light path is shortened and the optical path of the receiving light path is increased at the same time; or the distance between the mirror group and the back mirror group in the transmitting end transmission component is increased, the distance between the mirror group and the back mirror group in the receiving end transmission component is reduced, the optical path of the transmitting light path is increased and the optical path of the receiving light path is shortened at the same time. The present technical scheme can quickly adjust the optical path difference between the transmitting light path and the receiving light path, so as to save the time required for optical path compensation when the terahertz time-domain spectrometer switches different modules. Since the optical path difference between the transmitting light path and the receiving light path corresponds to the scanning length in the terahertz time-domain spectrometer, the present technical scheme also improves the scanning speed when the terahertz time-domain spectrometer performs slow scanning.

[0008] Further, the connecting light path includes two or more continuous round-trip light paths;The round-trip light path starts from the mirror group and is folded back to the mirror group at the back mirror group.

[0009] The laser is emitted from the mirror group, reflected and folded back to the mirror group in the back mirror group, forming a round-trip light path. Two or more continuous round-trip light paths refer to two or more round-trip light paths connected end to end. The technical solution realizes the increase of the light path of the connecting light path in a relatively small space, thereby prolonging the emission light path and the receiving light path, saving space, and providing a larger adjustment range for optical path compensation; by providing two or more continuous round-trip light paths, the optical path difference formed by the unchanged distance between the mirror group and the back mirror group changed by the mobile station in a single trip is multiplied; since the optical path difference between the emission light path and the receiving light path corresponds to the scanning length in the terahertz time-domain spectrometer, the technical solution also improves the scanning speed of the terahertz time-domain spectrometer when slow scanning is performed.

[0010] Further, in the transmission assembly at the emission end and / or the transmission assembly at the receiving end, the mirror group comprises first and second mirrors arranged side by side; the back mirror group comprises first and second back mirrors arranged side by side; the connecting light path is emitted from the first mirror, 180°-reflected at the first back mirror, returned to the first mirror, reflected by the first mirror to the second back mirror, 180°-reflected at the second back mirror, and returned to the second mirror.

[0011] Since the first and second mirrors are arranged side by side, and the first and second back mirrors are arranged side by side and 180°-reflected, the transmission of the laser between the mirror group and the back mirror group can always maintain a parallel trajectory; the technical solution forms two round-trip light paths, realizes the multiplication of the optical path difference, and the spatial layout of the connecting light path is reasonable, avoiding intersection and mutual interference, which is conducive to maintaining the stability of the connecting light path and reducing errors during the adjustment of the optical path difference.

[0012] Further, in the transmission assembly at the receiving end, the mirror group comprises first and second mirrors arranged side by side; the back mirror group comprises first and second back mirrors arranged side by side; the connecting light path is emitted from the first mirror, 180°-reflected at the first back mirror, returned to the first mirror, reflected by the first mirror to the second back mirror, 180°-reflected at the second back mirror, and returned to the second mirror; in the transmission assembly at the emission end, the mirror group comprises third and fourth mirrors; the back mirror group comprises third and fourth back mirrors; the connecting light path is emitted from the third mirror, 180°-reflected at the third back mirror, the fourth mirror, and the fourth back mirror in sequence, and reaches the third mirror; the third and fourth back mirrors are arranged on the same mirror body, and the mirror body, the third mirror, and the fourth mirror are located on the same straight line.

[0013] The mirror body is used for centrally arranging the third return mirror and the fourth return mirror. The technical scheme forms two round-trip light paths in the transmitting assembly and the receiving assembly, realizes multiplication of optical path difference, and has the advantages that the third return mirror and the fourth return mirror are arranged on the same mirror body, have good motion synchronization, and make the structure of the return mirror group more simple and centralized and the volume smaller; the mirror body, the third mirror and the fourth mirror are located on the same straight line, so that the connecting light path is in a bundle shape as a whole, the light path structure is more compact, and the occupied space is further saved.

[0014] Further, in the transmitting assembly and / or the receiving assembly, the mirror group comprises a third mirror and a fourth mirror; the return mirror group comprises a third return mirror and a fourth return mirror; the connecting light path starts from the third mirror, and sequentially undergoes 180° return reflection on the third return mirror, the fourth mirror and the fourth return mirror to reach the third mirror; the third return mirror and the fourth return mirror are arranged on the same mirror body, and the mirror body, the third mirror and the fourth mirror are located on the same straight line.

[0015] Further, the third return mirror and the fourth return mirror are arranged on the same action surface of the mirror body, the action surface comprises four identical return mirror surfaces, and the four identical return mirror surfaces are inclined to the inside of the mirror body, intersect at a point and are in a cross shape, and the third return mirror and the fourth return mirror each comprise two return mirror surfaces arranged diagonally on the action surface and perpendicular to each other.

[0016] Specifically, the third return mirror comprises two non-adjacent return mirror surfaces of the four identical return mirror surfaces in the cross shape, and the fourth return mirror comprises the other two non-adjacent return mirror surfaces. The technical scheme makes the return mirror group more centralized as a whole, saves the occupied space and reduces the volume; the diagonally arranged return mirror surfaces fold the space occupied by the connecting light path in the plane, form a bundle-shaped three-dimensional light path structure, do not affect the connection between the connecting light path and the external light path, and achieve the purpose of optimizing the light path; the number of parts is reduced, and the installation and assembly of the terahertz time-domain spectrometer are facilitated; the cross-shaped uniform distribution forms a symmetrical structure, so that the corresponding connecting light paths also have symmetry and are not easy to interfere with each other.

[0017] Further, the third mirror comprises two mirror surfaces perpendicular to each other and arranged in a V shape with the end portions facing the return mirror group; the fourth mirror comprises two mirror surfaces perpendicular to each other and arranged in a V shape with the openings facing the return mirror group; and the connecting light path starts from the mirror surface on one side of the third mirror and returns to the mirror surface on the other side of the third mirror.

[0018] The third mirror is used for connecting the emitting light path and the connecting light path in the transmitting assembly of the emitting end, and the two mirror surfaces are perpendicular to each other, arranged in a V shape and with the end directed to the return mirror group, so that the emitting light path is still parallel to the original incident direction after passing through the transmitting assembly of the emitting end, the light path layout is optimized, the possibility of light path intersection is reduced, and the cooperation of the fast optical path compensation device of the terahertz time-domain spectrometer and other modules in the terahertz time-domain spectrometer is facilitated. The fourth mirror is used for realizing the connection between the two return light paths, and the two mirror surfaces are perpendicular to each other, arranged in a V shape and with the opening directed to the return mirror group, so that the laser emitted from the third return mirror is turned back by 180 degrees to the fourth return mirror.

[0019] Further, the action surface has a transverse mirror intersection line, the top end height of the fourth mirror is level with the height of the transverse mirror intersection line, and the bottom end height is equal to or lower than the bottom end height of the action surface; the bottom end height of the third mirror is equal to or lower than the height of the transverse mirror intersection line, and the top end height is equal to or higher than the height of the action surface.

[0020] The transverse mirror intersection line is the intersection line between the two upper return mirror surfaces and the two lower return mirror surfaces on the action surface. The technical solution ensures the height difference between the third mirror and the fourth mirror and the correspondence with the third return mirror and the fourth return mirror respectively. The third return mirror and the fourth return mirror are both composed of two return mirror surfaces arranged diagonally on the action surface and perpendicular to each other, so the heights corresponding to the mirror surfaces are different. The technical solution limits the height of the third mirror and the fourth mirror through reasonable position layout, avoids the mutual interference of light beams, avoids the shielding of light beams, enables the light beams to reach the mirror surfaces completely, and guarantees the accuracy of the detection result.

[0021] A terahertz time-domain spectrometer comprising the terahertz time-domain spectrometer fast optical path compensation device, further comprising a base plate and a motor, the terahertz time-domain spectrometer fast optical path compensation device is arranged on the base plate, a straight rail is installed on the base plate, and the motor drives the moving table to reciprocate along the straight rail.

[0022] The motor is used for optical path compensation and scanning. The movement along the straight rail is relatively stable, and the control and calculation of the stroke of the moving table are facilitated.

[0023] Further, the terahertz time-domain spectrometer further comprises a beam splitter, the beam splitter is used for dividing the light emitted by the light source device into pump light and probe light, and the pump light and the probe light enter the emitting light path and the receiving light path respectively.

[0024] The terahertz time-domain spectrometer realizes that the optical paths of the pump light and the probe light are equal at the position of the receiving assembly through the terahertz time-domain spectrometer fast optical path compensation device, and the waiting time for optical path compensation after the switching module is relatively short.

[0025] Compared with the prior art, the present application has the following advantages:

[0026] The single stroke of the moving table can change the distance between the mirror group and the return mirror group in the transmitting assembly and the receiving assembly, thereby adjusting the transmitting light path and the receiving light path at the same time, performing optical path compensation, realizing the rapid adjustment of the optical path difference between the transmitting light path and the receiving light path, saving the time required for optical path compensation when the terahertz time-domain spectrometer switches different modules; since the optical path difference between the transmitting light path and the receiving light path corresponds to the scanning length in the terahertz time-domain spectrometer, the present technical solution also improves the scanning speed when the terahertz time-domain spectrometer performs slow scanning.

[0027] By setting two or more continuous round-trip light paths, the optical path difference formed by the unchanged distance between the mirror group and the return mirror group in the single stroke of the moving table is multiplied; the growth of the connecting light path is realized in a relatively small space, thereby prolonging the transmitting light path and the receiving light path and saving space to provide a larger adjustment range for optical path compensation.

[0028] The return mirror group occupies a small space and reduces the number of parts, facilitating the installation and assembly of the terahertz time-domain spectrometer; the diagonally arranged return mirror surfaces fold the space occupied by the flat laying of the connecting light path through the height difference, forming a bundle-shaped three-dimensional light path structure without affecting the connection between the connecting light path and the external light path, thereby achieving the purpose of optimizing the light path; the symmetric structure formed by the "cross" type uniform distribution makes the corresponding connecting light path also have symmetry and is not easy to interfere with each other. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a perspective view of the present application.

[0030] Figure 2 It is a structural schematic view of the present application.

[0031] Figure 3 It is a right view of the present application hiding the first mirror and the second mirror.

[0032] Figure 4 It is a right view of the present application hiding the third mirror and the fourth mirror.

[0033] Explanation of reference numerals in the attached diagram: Light source device 100, transmitting component 200, receiving component 300, base plate 400, straight rail 410, moving stage 420, support plate 430, connecting plate 440, motor 450, transmitting end transmission component 500, third reflector 510, first mirror 511, second mirror 512, third retroreflector 520, third mirror 521, fourth mirror 522, fourth reflector 530, fifth mirror 531, sixth mirror 532, fourth retroreflector 540, seventh mirror 541, eighth mirror 542, mirror body 550, transverse mirror intersection line 551, longitudinal mirror intersection line 552, receiving end transmission component 600, first reflector 610, first retroreflector 620, second reflector 630, second retroreflector 640, transmitting optical path 700, receiving optical path 800, beam splitter 900. Detailed Implementation

[0034] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the invention. To better illustrate the following embodiments, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions; it is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0035] Example 1

[0036] like Figure 1 As shown, this embodiment is a rapid optical path compensation device for a terahertz time-domain spectrometer, including a light source device 100, a transmitting component 200, and a receiving component 300. A transmitting optical path 700 connects the light source device 100 and the transmitting component 200, and a receiving optical path 800 connects the light source device 100 and the receiving component 300. It also includes a reciprocating moving stage 420, a transmitting end transmission component 500, and a receiving end transmission component 600. Both the transmitting end transmission component 500 and the receiving end transmission component 600 include a mirror group and a retroreflector group arranged opposite each other, and a connecting optical path connecting the mirror group and the retroreflector group. The retroreflector group is mounted on the moving stage 420. The connecting optical path in the transmitting end transmission component 500 is connected to the transmitting optical path 700; the connecting optical path in the receiving end transmission component 600 is connected to the receiving optical path 800. The reciprocating motion of the moving stage 420 drives the retroreflector group to move relative to the mirror group, adjusting the optical path difference between the transmitting optical path 700 and the receiving optical path 800.

[0037] The light source device 100 is used for emitting laser. The emitting assembly 200 is used for converting the laser into a terahertz signal to emit to a sample to be measured. The emitting light path 700 is a light path of pump light. The receiving light path 800 is a light path of probe light. The receiving assembly 300 is used for receiving the terahertz signal carrying information of the sample to be measured. The moving table 420 is used for carrying a return mirror group and driving the return mirror group to move relative to the mirror group. The emitting end transmission assembly 500 is used for adjusting an optical path of the emitting light path 700, and the receiving end transmission assembly 600 is used for adjusting an optical path of the receiving light path 800.

[0038] Compared with adjusting the emitting light path 700 or the receiving light path 800 alone, in the technical solution, a single stroke of the moving table 420 can change the distance between the return mirror group and the mirror group in the emitting end transmission assembly 500 and the receiving end transmission assembly 600, so as to adjust the emitting light path 700 and the receiving light path 800 simultaneously and compensate the optical path. Specifically, reducing the distance between the mirror group and the return mirror group in the emitting end transmission assembly 500 and increasing the distance between the mirror group and the return mirror group in the receiving end transmission assembly 600 can shorten the optical path of the emitting light path 700 and lengthen the optical path of the receiving light path 800 at the same time; or increasing the distance between the mirror group and the return mirror group in the emitting end transmission assembly 500 and reducing the distance between the mirror group and the return mirror group in the receiving end transmission assembly 600 can lengthen the optical path of the emitting light path 700 and shorten the optical path of the receiving light path 800 at the same time. The technical solution can quickly adjust the optical path difference between the emitting light path 700 and the receiving light path 800, so that the terahertz time-domain spectrometer saves the time required for optical path compensation when switching different modules; since the optical path difference between the emitting light path 700 and the receiving light path 800 corresponds to the scanning length in the terahertz time-domain spectrometer, the technical solution also improves the scanning speed of the terahertz time-domain spectrometer when performing slow scanning.

[0039] As shown in Figure 2 The connecting light path includes two or more continuous round-trip light paths. The round-trip light path starts from the mirror group and is folded back to the mirror group at the return mirror group.

[0040] The laser is emitted from the mirror set, reflected and folded back to the mirror set in the return mirror set, forming a round-trip light path. Two or more continuous round-trip light paths refer to two or more round-trip light paths connected end to end. The technical solution realizes the increase of the light path of the connected light path in a relatively small space, thereby prolonging the emission light path 700 and the receiving light path 800, saving space, and providing a larger adjustment range for optical path compensation; by providing two or more continuous round-trip light paths, the light path difference formed by the unchanged distance between the mirror set and the return mirror set changed by the mobile station 420 in a single trip is doubled; since the light path difference between the emission light path 700 and the receiving light path 800 corresponds to the scanning length in the terahertz time-domain spectrometer, the technical solution also improves the scanning speed of the terahertz time-domain spectrometer when performing slow scanning.

[0041] The emission end transmission assembly 500 and the receiving end transmission assembly 600 can be the same structure or different structures. As shown in Figure 1 and 2 In the receiving end transmission assembly 600, the mirror set includes the first mirror 610 and the second mirror 630 arranged side by side; the return mirror set includes the first return mirror 620 and the second return mirror 640 arranged side by side; the connected light path is emitted from the first mirror 610, 180°-reflected at the first return mirror 620, returned to the first mirror 610, reflected by the first mirror 610 to the second return mirror 640, 180°-reflected at the second return mirror 640, and returned to the second mirror 630; in the emission end transmission assembly 500, the mirror set includes the third mirror 510 and the fourth mirror 530; the return mirror set includes the third return mirror 520 and the fourth return mirror 540; the connected light path is emitted from the third mirror 510, 180°-reflected at the third return mirror 520, the fourth mirror 530, and the fourth return mirror 540 in turn, and reaches the third mirror 510; the third return mirror 520 and the fourth return mirror 540 are arranged on the same mirror body 550, and the mirror body 550, the third mirror 510, and the fourth mirror 530 are located on the same straight line.

[0042] Since the first mirror 610 and the second mirror 630 are arranged side by side, the first return mirror 620 and the second return mirror 640 are arranged side by side and occur 180° return reflection, the transmission of the laser between the mirror group and the return mirror group can always keep the trajectories parallel to each other; the technical solution forms two round-trip light paths, realizes the multiplication of the optical path difference; the spatial layout of the connecting light path is reasonable, avoids intersection and mutual interference, and is conducive to maintaining the stability of the connecting light path in the process of adjusting the optical path difference and reducing errors. The mirror body 550 is used for centrally arranging the third return mirror 520 and the fourth return mirror 540. The technical solution forms two round-trip light paths in the transmitting end transmission assembly 500 and the receiving end transmission assembly 600, realizes the multiplication of the optical path difference; the third return mirror 520 and the fourth return mirror 540 are arranged on the same mirror body 550, have good motion synchronization, and also make the structure of the return mirror group more simple and centralized, and reduce the volume; the mirror body 550, the third mirror 510 and the fourth mirror 530 are located on the same straight line, so that the connecting light path is in a bundle as a whole, the light path structure is more compact, and the occupied space is further saved.

[0043] As shown in Figure 4 , the third return mirror 520 and the fourth return mirror 540 are arranged on the same action surface of the mirror body 550, the action surface includes four identical return mirror surfaces, which are inclined to the inside of the mirror body 550 and intersect at a point and are in a "cross" shape, and the third return mirror 520 and the fourth return mirror 540 are each composed of two return mirror surfaces arranged diagonally on the action surface and perpendicular to each other.

[0044] Specifically, the third return mirror 520 is composed of two non-adjacent return mirror surfaces of the four identical return mirror surfaces in a "cross" shape, and the fourth return mirror 540 is composed of the other two non-adjacent return mirror surfaces. The technical solution makes the return mirror group more centralized as a whole, saves the occupied space, and reduces the volume; the diagonally arranged return mirror surfaces fold the space occupied by the connecting light path laid flat on the plane through the height difference, form a bundle-shaped three-dimensional light path structure, and do not affect the connection of the connecting light path and the external light path, achieving the purpose of optimizing the light path; reducing parts facilitates the installation of the terahertz time-domain spectrometer; the "cross" shape is uniformly distributed to form a symmetrical structure, so that the corresponding connecting light paths also have symmetry and are not easy to interfere with each other.

[0045] As shown in Figure 1 and 2 , the third mirror 510 includes two mirror surfaces perpendicular to each other and arranged in a "V" shape with the end part facing the return mirror group; the fourth mirror 530 includes two mirror surfaces perpendicular to each other and arranged in a "V" shape with the opening facing the return mirror group; the connecting light path starts from the mirror surface on one side of the third mirror 510 and returns to the mirror surface on the other side of the third mirror 510.

[0046] The third mirror 510 is used to connect the emitting light path 700 and the connecting light path in the emitting end transmission assembly 500, the two mirror surfaces are perpendicular to each other, arranged in a "V" shape and the end is towards the back mirror group, so that the emitting light path 700 is still parallel to the original incident direction after passing through the emitting end transmission assembly 500, the light path layout is optimized, the possibility of light path intersection is reduced, and the cooperation of the terahertz time domain spectrometer fast optical path compensation device and other modules in the terahertz time domain spectrometer is facilitated. The fourth mirror 530 is used to realize the connection between the two round-trip light paths, the two mirror surfaces are perpendicular to each other, arranged in a "V" shape and the opening is towards the back mirror group, so that the laser emitted from the third back mirror 520 is turned back 180° to the fourth back mirror 540.

[0047] The third mirror 510 is a roof prism, and the fourth mirror 530 is a V-shaped prism, both of which are gold-plated. Compared with the plane mirror matched with the mirror frame, the mutual perpendicularity of the mirror surfaces can be ensured, the shielding phenomenon can be avoided, and the occupied space size is smaller.

[0048] As shown in Figure 4 , the acting surface has a transverse mirror intersection line 551, the top end height of the fourth mirror 530 is level with the height of the transverse mirror intersection line 551, and the bottom end height is equal to or lower than the bottom end height of the acting surface; the bottom end height of the third mirror 510 is equal to or lower than the height of the transverse mirror intersection line 551, and the top end height is equal to or higher than the height of the acting surface.

[0049] The transverse mirror intersection line 551 is the intersection line between the upper two back mirror surfaces and the lower two back mirror surfaces on the acting surface. The technical solution ensures the height difference between the third mirror 510 and the fourth mirror 530 and the correspondence with the third back mirror 520 and the fourth back mirror 540 respectively. The third back mirror 520 and the fourth back mirror 540 are both composed of two back mirror surfaces arranged diagonally on the acting surface and perpendicular to each other, so the heights corresponding to the mirror surfaces are different. The technical solution limits the height of the third mirror 510 and the fourth mirror 530 through reasonable position layout, avoids the mutual interference of light beams, and also avoids the shielding of light beams, so that the light beams can be completely reflected on the mirror surfaces, and the accuracy of the detection result is ensured.

[0050] As shown in Figure 4 , the acting surface has a longitudinal mirror intersection line, the longitudinal mirror intersection line, the intersection line of the first mirror 511 and the second mirror 512, and the intersection line of the fifth mirror 531 and the sixth mirror 532 are on the same plane.

[0051] The longitudinal mirror intersection line 552 is the intersection line between the left two back mirror surfaces and the right two back mirror surfaces on the acting surface. The technical solution makes the connecting light path as a whole have symmetry, avoiding the conflict and interference of light beams.

[0052] A terahertz time-domain spectrometer comprising the fast optical path compensation device of the terahertz time-domain spectrometer, further comprising a base plate 400 and a motor 450, the fast optical path compensation device of the terahertz time-domain spectrometer is arranged on the base plate 400, the base plate 400 is provided with a straight rail 410, and the motor 450 drives the moving platform 420 to reciprocate along the straight rail 410.

[0053] The motor 450 is used for optical path compensation and scanning. The movement along the straight rail 410 is relatively stable, and the stroke control and calculation of the moving platform 420 are facilitated. Figure 1 As shown in the figure, the moving platform 420 is provided with a support plate 430 and a connecting plate 440, the support plate 430 is used for fixedly mounting the mirror body 550, and the connecting plate 440 is used for fixedly mounting the first return mirror 620 and the second return mirror 640.

[0054] As shown in the figure, the terahertz time-domain spectrometer further comprises a beam splitter 900, the beam splitter 900 is used for dividing the light emitted by the light source device 100 into pump light and probe light, and the pump light and the probe light enter the emission light path 700 and the receiving light path 800 respectively. Figure 2

[0055] The terahertz time-domain spectrometer realizes that the optical paths of the pump light and the probe light at the receiving assembly 300 position are equal through the fast optical path compensation device of the terahertz time-domain spectrometer, and the waiting time for optical path compensation after the switching module is relatively short.

[0056] The return mirror groups in the emission end transmission assembly 500 and the return mirror groups in the receiving end transmission assembly 600 are oppositely arranged on the moving platform 420, and the corresponding mirror groups are arranged at both ends of the straight rail 410 and are on the same straight line, so that the corresponding variables have a multiple relationship: one stroke of the moving platform 420 simultaneously forms a four-fold optical path difference in the emission light path 700 and the receiving light path 800, realizes eight-fold optical path compensation of the moving platform 420 stroke, greatly shortens the time required for completing optical path compensation; since the optical path difference between the emission light path 700 and the receiving light path 800 corresponds to the scanning length in the terahertz time-domain spectrometer, the technical solution also improves the scanning speed by one time.

[0057] As shown in the figure, Figure 2 ​As shown, the third mirror 510 includes a first mirror surface 511 and a second mirror surface 512, the third return mirror 520 includes a third mirror surface 521 and a fourth mirror surface 522, the fourth mirror 530 includes a fifth mirror surface 531 and a sixth mirror surface 532, and the fourth return mirror 540 includes a seventh mirror surface 541 and an eighth mirror surface 542. The emitting light path 700 starts from the light source device 100, passes through the beam splitter 900, the first mirror surface 511, the third mirror surface 521, the fourth mirror surface 522, the fifth mirror surface 531, the sixth mirror surface 532, the seventh mirror surface 541, the eighth mirror surface 542, and the second mirror surface 512 in sequence, and reaches the emitting assembly 200; the receiving light path 800 starts from the light source device 100, passes through the beam splitter 900, the first mirror 610, the first return mirror 620, the first mirror 610, the second mirror 630, the second return mirror 640, and the second mirror 630 in sequence, and reaches the receiving assembly 300.

[0058] Obviously, the above embodiments of the present application are merely exemplary for clearly illustrating the technical solutions of the present application, but are not intended to limit the specific embodiments of the present application. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A terahertz time-domain spectrometer rapid optical path compensation device, comprising a light source device, a transmitting assembly and a receiving assembly, a transmitting light path is connected between the light source device and the transmitting assembly, and a receiving light path is connected between the light source device and the receiving assembly, characterized in that, Also include reciprocating motion of the moving platform, the transmitting assembly and receiving end transmission components; the transmitting assembly and receiving end transmission components both include the relative arrangement of mirror group and back mirror group and connecting mirror group and back mirror group connecting light path, the back mirror group is arranged on the moving platform; the transmitting assembly in the connecting light path access transmitting light path; the connecting light path in the receiving end transmission components access receiving light path; the moving platform reciprocating motion, drive back mirror group relative to the mirror group motion, adjust the optical path difference between transmitting light path and receiving light path, in the receiving end transmission components, the mirror group includes side by side arranged first mirror and second mirror; the back mirror group includes side by side arranged first back mirror and second back mirror; the connecting light path from the first mirror, in the first back mirror 180° back reflection, back to the first mirror, through the first mirror reflection to the second back mirror, in the second back mirror 180° back reflection, back to the second mirror; In the transmitting assembly, the mirror group includes third mirror and fourth mirror; the back mirror group includes third back mirror and fourth back mirror; the connecting light path from the third mirror, in turn in the third back mirror, fourth mirror and fourth back mirror 180° back reflection, to the third mirror; the third back mirror and fourth back mirror are arranged on the same mirror body, the mirror body, third mirror and fourth mirror are located on the same straight line.

2. The rapid optical path compensation device of a terahertz time-domain spectrometer according to claim 1, characterized in that, The connecting light path includes two or more continuous round trip light path; the round trip light path from the mirror group, back to the mirror group in the back mirror group.

3. The rapid optical path compensation device of a terahertz time-domain spectrometer according to claim 2, characterized in that, In the transmitting assembly and / or receiving end transmission components, the mirror group includes side by side arranged first mirror and second mirror; the back mirror group includes side by side arranged first back mirror and second back mirror; the connecting light path from the first mirror, in the first back mirror 180° back reflection, back to the first mirror, through the first mirror reflection to the second back mirror, in the second back mirror 180° back reflection, back to the second mirror.

4. The quick optical path compensation device of a terahertz time-domain spectrometer according to claim 2, characterized in that, In the transmitting assembly and / or receiving end transmission components, the mirror group includes third mirror and fourth mirror; the back mirror group includes third back mirror and fourth back mirror; the connecting light path from the third mirror, in turn in the third back mirror, fourth mirror and fourth back mirror 180° back reflection, to the third mirror; the third back mirror and fourth back mirror are arranged on the same mirror body, the mirror body, third mirror and fourth mirror are located on the same straight line.

5. The rapid optical path compensation device of a terahertz time-domain spectrometer according to claim 1 or 4, characterized in that, The third back mirror and fourth back mirror are arranged on the same action surface of the mirror body, the action surface includes four identical back mirror surfaces, which are inclined to the inside of the mirror body and intersect at a point and are distributed in the shape of a cross, the third back mirror and the fourth back mirror are both composed of two back mirror surfaces arranged diagonally on the action surface and perpendicular to each other.

6. The quick optical path compensation device of a terahertz time-domain spectrometer according to claim 5, wherein, The third reflecting mirror comprises two mirror surfaces arranged in a "V" shape and perpendicular to each other, and the end thereof is directed to the back reflecting mirror group; the fourth reflecting mirror comprises two mirror surfaces arranged in a "V" shape and perpendicular to each other, and the opening thereof is directed to the back reflecting mirror group; the connecting light path starts from the mirror surface on one side of the third reflecting mirror and returns to the mirror surface on the other side of the third reflecting mirror.

7. The quick optical path compensation device of a terahertz time-domain spectrometer according to claim 6, wherein, The top end height of the fourth reflecting mirror is equal to the height of the intersection of the lateral mirror surfaces, and the bottom end height is equal to or lower than the bottom end height of the action surface; the bottom end height of the third reflecting mirror is equal to or lower than the height of the intersection of the lateral mirror surfaces, and the top end height is equal to or higher than the height of the action surface.

8. A terahertz time-domain spectrometer, characterized by, The fast optical path compensation device of the terahertz time-domain spectrometer comprises a base plate and a motor, and the fast optical path compensation device of the terahertz time-domain spectrometer is arranged on the base plate, a straight rail is installed on the base plate, and the motor drives the moving table to reciprocate along the straight rail.

9. The terahertz time-domain spectrometer according to claim 8, characterized in that The device further comprises a beam splitter for splitting the light emitted by the light source device into pump light and probe light, which enter the emitting light path and the receiving light path, respectively.

Images