阅读说明：本技术 一种中阶梯光栅拼接方法和系统 (Echelle grating splicing method and system ) 是由 糜小涛 李文昊 于宏柱 李逸凡 江思博 周敬萱 高键翔 于 2021-08-13 设计创作，主要内容包括：本发明提供了一种中阶梯光栅拼接方法和系统,该系统采用了剪切干涉技术,当一束光照射到剪切板上,会在其前后两个面各产生一次反射,两束反射光之间会产生一个横向剪切量,重叠部分会产生干涉条纹。如果入射光由两束相邻且近似平行的光束组成,则干涉区域会分为三个区域。两束光的相对预定方位会影响中间区域的条纹模式,因而本发明通过测量干涉条纹对应的周期和旋转判断误差种类,并定量计算误差数值后对误差进行校准,实现光栅严格拼接。(The invention provides a splicing method and a splicing system for echelle gratings, which adopt a shearing interference technology, when a beam of light irradiates a shearing plate, primary reflection is respectively generated on the front surface and the rear surface of the shearing plate, a transverse shearing amount is generated between the two beams of reflected light, and an interference fringe is generated on an overlapped part. If the incident light consists of two adjacent and approximately parallel beams, the interference region is divided into three regions. The relative preset direction of the two beams can affect the fringe pattern of the middle area, so the invention judges the error type by measuring the period and rotation corresponding to the interference fringe, and calibrates the error after quantitatively calculating the error value, thereby realizing the strict splicing of the grating.)

1. The echelle grating splicing method is characterized by being applied to an echelle grating splicing system, wherein the system is arranged on a turntable and comprises a light source, a beam splitter, a splicing mechanism, a shear plate and an image acquisition unit; the splicing mechanism is provided with a plane reflector or a splicing grating; the light beam emitted by the light source is divided into a first light beam and a second light beam by a beam splitter, the first light beam enters the splicing mechanism, and the second light beam is reflected by the shear plate and then captured by the image acquisition unit;

the method comprises the following steps:

a plane reflector is arranged on the splicing mechanism, a rotary zero point of the rotary table is calibrated through the reflected light corresponding to the first light beam, the period of the stripe at the moment is recorded, and the proportion of the number of pixels corresponding to the period of the stripe shot by the image acquisition unit to the actual length is calculated;

the plane mirror is detached from the splicing mechanism, a spliced grating is installed on the splicing mechanism, the rotary table is rotated to a first preset angle, the slope of the current stripe on the screen of the shear plate is measured, a first error delta theta y is calculated according to the slope, an actuator is controlled to carry out first calibration on the first error delta theta y, and the current stripe period vp1 after the first calibration is recorded;

rotating the turntable to a second preset angle, recording a rotated stripe period vp2, calculating a second error delta theta x and a third error delta theta z according to the stripe period vp1 and the stripe period vp2, controlling an actuator to perform second calibration on the second error delta theta x and the third error delta theta z, and recording current stripe dislocation delta phi 2;

and rotating the rotary table back to a first preset angle, recording the stripe dislocation delta phi 1 at the moment, calculating a fourth error delta x and a fifth error delta z according to the stripe dislocation delta phi 2 and the stripe dislocation delta phi 1, and controlling an actuator to carry out third calibration on the fourth error delta x and the fifth error delta z.

2. The echelle grating stitching method of claim 1, wherein the first error Δ θ Y is a rotation error of the stitched grating about a Y-axis direction, the second error Δ θ X is a rotation error of the stitched grating about an X-axis direction, the third error Δ θ Z is a rotation error of the stitched grating about a Z-axis direction, the fourth error Δ X is a displacement error of the stitched grating along a coordinate X-axis direction, and the fifth error Δ Z is a displacement error of the stitched grating along the coordinate Z-axis direction;

the first error Δ θ x, the second error Δ θ x, the third error Δ θ z, the fourth error Δ x, and the fifth error Δ z satisfy the following equations:

wherein λ represents wavelength, α represents grating incident angle, β represents diffraction angle, m represents diffraction order, φ_zIndicating the phase misalignment along the direction of propagation, d phi/dx and d phi/dy indicating the phase gradient of the wavefront.

3. The echelle grating stitching method of claim 2, wherein the fringe period comprises a period of the interference fringe in the u direction and a period of the interference fringe in the v direction; the calculation formula is as follows:

wherein v is_pThe period of the interference fringe in the u direction, u_pIs the period of the interference fringes in the v direction.

4. The echelle grating stitching method of claim 2, wherein the fringe misalignment Δ Φ 2 and the fringe misalignment Δ Φ 1 refer to misalignment of interference fringes in the u direction, and the calculation formula is as follows:

5. the echelle grating stitching method of claim 3, wherein the slope calculation formula is as follows:

6. the echelle grating stitching method of claim 1, wherein the first predetermined angle is a littrow angle of 64.137 ° on the order of-36.

7. The echelle grating stitching method of claim 1, wherein the second predetermined angle is a-37 littrow angle of 67.644 °.

8. An echelle grating splicing system is characterized in that the system is arranged on a rotary table and comprises a light source, a beam splitter, a splicing mechanism, a shear plate and an image acquisition unit; the splicing mechanism is provided with a plane reflector or a splicing grating; the light beam emitted by the light source is divided into a first light beam and a second light beam by a beam splitter, the first light beam enters the splicing mechanism, and the second light beam is reflected by the shear plate and then captured by the image acquisition unit;

the echelle grating stitching system is adapted to perform the method steps of any one of claims 1 to 7.

9. The echelle grating stitching system of claim 8, wherein the stitching grating comprises a first grating and a second grating, and the actuator comprises a first actuator and a second actuator; the first actuator is used for adjusting the error of the first grating, and the second actuator is used for adjusting the error of the second grating.

10. The echelle grating stitching system of claim 9, wherein the first actuator and the second actuator are both piezoceramics.

Technical Field

The invention relates to the field of optical precision detection, in particular to a method and a system for splicing echelle gratings.

Background

The diffraction grating has important application in a plurality of scientific engineering fields such as spectrum observation, precision measurement, high-energy pulse compression and the like, wherein the large-caliber echelle grating has an extremely important position in the field of astronomical spectrum observation. The manufacturing of large-aperture gratings has certain technical difficulty, and as an alternative method, small-aperture gratings with more mature manufacturing technology are spliced into a grating group, so that the engineering difficulty is reduced to a certain extent while the optical performance similar to that of a single large grating is obtained, and the cost is possibly reduced.

Errors with six degrees of freedom (including three translation errors and three rotation errors) are generated when the two gratings are spliced, wherein the translation errors parallel to the reticle direction can be considered not to affect the splicing quality, and the rest five errors all affect the diffraction wavefront. Depending on the relationship between the error and the wavefront, some errors will be complementary, so that it is necessary to separate the different errors by observation.

One type of the common grating splicing technologies is a diffraction method, namely, the wave front phase is calculated by observing the energy distribution condition of a far-field diffraction spot of a grating group. The other is interferometry, where the wavefront is calculated by observing the near-field interference fringes of the grating set. The method for directly observing by using the Fizeau interferometer needs to repeatedly adjust the position of the interferometer to observe different levels, needs to match a phase shifting technology for realizing quantitative calculation, and has complex flow and high requirement on environmental vibration; displacement errors are not strictly corrected by adopting a method of matching a laser non-equal diameter interferometer (LUPI) with an altimeter by the ESPRESSO of the southern European astronomical observatory; the dual wavelength heterodyne interferometry method proposed by qinghua yinjiang et al does not strictly correct rotation errors.

The conventional approach to grating stitching is to correct for the remaining errors by first measuring the zero order, separating the two errors, and then measuring the diffraction order (typically 1 order). Echelle gratings typically do not directly interfere with the zero order and must measure the diffraction order.

In the conventional method, in order to realize error separation, at least two measurements under different conditions (in the case of different wavelengths, incidence angles or diffraction orders) are required, but the echelle grating must measure two different orders because it measures diffraction orders, cannot change only the wavelength or the incidence angle, and the greatest common divisor of the two measured orders m1 and m2 must be 1, otherwise, the result has a defect in principle. The current methods do not specifically address this issue.

Disclosure of Invention

In order to overcome the problems in the prior art, the application provides a solution for splicing the echelle grating, and the solution is used for realizing splicing and error calibration of the echelle grating.

In order to achieve the purpose, the invention adopts the following specific technical scheme:

the invention provides a method for splicing echelle gratings, which is applied to an echelle grating splicing system, wherein the system is arranged on a turntable and comprises a light source, a beam splitter, a splicing mechanism, a shear plate and an image acquisition unit; the splicing mechanism is provided with a plane reflector or a splicing grating; the light beam emitted by the light source is divided into a first light beam and a second light beam by a beam splitter, the first light beam enters the splicing mechanism, and the second light beam is reflected by the shear plate and then captured by the image acquisition unit;

the method comprises the following steps:

a plane reflector is arranged on the splicing mechanism, a rotary zero point of the rotary table is calibrated through the reflected light corresponding to the first light beam, the period of the stripe at the moment is recorded, and the proportion of the number of pixels corresponding to the period of the stripe shot by the image acquisition unit to the actual length is calculated;

the plane mirror is detached from the splicing mechanism, a spliced grating is installed on the splicing mechanism, the rotary table is rotated to a first preset angle, the slope of the current stripe on the screen of the shear plate is measured, a first error delta theta y is calculated according to the slope, an actuator is controlled to carry out first calibration on the first error delta theta y, and the current stripe period vp1 after the first calibration is recorded;

rotating the turntable to a second preset angle, recording a rotated stripe period vp2, calculating a second error delta theta x and a third error delta theta z according to the stripe period vp1 and the stripe period vp2, controlling an actuator to perform second calibration on the second error delta theta x and the third error delta theta z, and recording current stripe dislocation delta phi 2;

and rotating the rotary table back to a first preset angle, recording the stripe dislocation delta phi 1 at the moment, calculating a fourth error delta x and a fifth error delta z according to the stripe dislocation delta phi 2 and the stripe dislocation delta phi 1, and controlling an actuator to carry out third calibration on the fourth error delta x and the fifth error delta z.

As an alternative embodiment, the first error Δ θ Y is a rotation error of the tiled grating around a Y-axis direction, the second error Δ θ X is a rotation error of the tiled grating around an X-axis direction, the third error Δ θ Z is a rotation error of the tiled grating around a Z-axis direction, the fourth error Δ X is a displacement error of the tiled grating along a coordinate X-axis direction, and the fifth error Δ Z is a displacement error of the tiled grating along a coordinate Z-axis direction;

the first error Δ θ x, the second error Δ θ x, the third error Δ θ z, the fourth error Δ x, and the fifth error Δ z satisfy the following equations:

wherein λ represents wavelength, α represents grating incident angle, β represents diffraction angle, m represents diffraction order, φ_zIndicating the phase misalignment along the direction of propagation, d phi/dx and d phi/dy indicating the phase gradient of the wavefront.

As an alternative embodiment, the fringe period includes a period of the interference fringe in the u direction and a period of the interference fringe in the v direction; the calculation formula is as follows:

wherein v is_pThe period of the interference fringe in the u direction, u_pIs the period of the interference fringes in the v direction.

As an alternative embodiment, the fringe offset Δ Φ 2 and the fringe offset Δ Φ 1 refer to the offset of the interference fringe in the u direction, and the calculation formula is as follows:

as an alternative embodiment, the slope calculation formula is as follows:

as an alternative embodiment, the first predetermined angle is a littrow angle 64.137 ° of-36 steps.

As an alternative embodiment, the second predetermined angle is a littrow angle 67.644 ° of-37.

The HIA in the second aspect of the invention provides an echelle grating splicing system which is arranged on a turntable and comprises a light source, a beam splitter, a splicing mechanism, a shear plate and an image acquisition unit; the splicing mechanism is provided with a plane reflector or a splicing grating; the light beam emitted by the light source is divided into a first light beam and a second light beam by a beam splitter, the first light beam enters the splicing mechanism, and the second light beam is reflected by the shear plate and then captured by the image acquisition unit;

the echelle grating stitching system is for performing the method steps according to the first aspect of the invention.

As an alternative embodiment, the tiled grating includes a first grating and a second grating, and the actuator includes a first actuator and a second actuator; the first actuator is used for adjusting the error of the first grating, and the second actuator is used for adjusting the error of the second grating.

As an alternative embodiment, the first actuator and the second actuator are both piezoceramic.

The invention provides a splicing method and a splicing system for echelle gratings, which adopt a shearing interference technology, when a beam of light irradiates a shearing plate, primary reflection is respectively generated on the front surface and the rear surface of the shearing plate, a transverse shearing amount is generated between the two beams of reflected light, and an interference fringe is generated on an overlapped part. If the incident light consists of two adjacent and approximately parallel beams, the interference region is divided into three regions. The relative preset direction of the two beams can affect the fringe pattern of the middle area, so the invention judges the error type by measuring the period and rotation corresponding to the interference fringe, and calibrates the error after quantitatively calculating the error value, thereby realizing the strict splicing of the grating.

Drawings

Fig. 1 is a flowchart of an echelle grating stitching method according to an embodiment of the present invention;

FIG. 2 is a schematic diagram illustrating the echelle grating splicing principle according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of shearing interferometry for measuring errors of two adjacent approximately parallel beams according to an embodiment of the present invention;

FIG. 4 is a diagram illustrating the effect of different errors on interference fringes according to one embodiment of the present invention;

FIG. 5 is an optical path diagram of an echelle grating splicing system according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of an echelle grating stitching system according to an embodiment of the present invention;

FIG. 7 is an optical schematic diagram of an echelle grating stitching system according to another embodiment of the present invention;

wherein the reference numerals are:

1. a light source;

2. a beam splitter;

3. a splicing mechanism;

4. a first grating;

5. a second grating;

6. a shear plate; 61. a first shear plate; 62. a second shear plate;

7. a screen of a clipboard; 71. a screen of a first shear plate; 72. a screen of a second shear plate;

8. an image acquisition unit; 81. a first image acquisition unit; 82. a second image acquisition unit;

11. a first grating placement position;

12. a second grating placement position;

13. a second actuator;

14. a first connecting member;

15. a second connecting member;

16. a first actuator;

17. a first rotation control mechanism;

18. a second rotation control mechanism;

19. a third connecting member;

20. a third rotation control mechanism;

21. a fourth connecting member;

22. a turntable.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention.

As shown in fig. 1, in a first aspect, the present invention provides an echelle grating splicing method, including the steps of:

firstly, step S101 is carried out, a plane reflector is arranged on the splicing mechanism, a rotary zero point of the rotary table is calibrated through reflected light corresponding to the first light beam, a fringe period at the moment is recorded, and the proportion of the number of pixels corresponding to the fringe period shot by the image acquisition unit to the actual length is calculated;

then, step S102 is carried out, the plane mirror is detached from the splicing mechanism, a spliced grating is installed on the splicing mechanism, the rotary table is rotated to a first preset angle, the slope of the current stripe on the screen of the shear plate is measured, a first error delta theta y is calculated according to the slope, an actuator is controlled to carry out first calibration on the first error delta theta y, and the current stripe period vp1 after the first calibration is recorded;

then, step S103 is carried out, the rotary table is rotated to a second preset angle, the rotated fringe period vp2 is recorded, a second error delta theta x and a third error delta theta z are calculated according to the fringe period vp1 and the fringe period vp2, the actuator is controlled to carry out second calibration on the second error delta theta x and the third error delta theta z, and the current fringe dislocation delta phi 2 is recorded;

and then, step S104 is carried out, the rotary table is rotated back to a first preset angle, the stripe dislocation delta phi 1 at the moment is recorded, a fourth error delta x and a fifth error delta z are calculated according to the stripe dislocation delta phi 2 and the stripe dislocation delta phi 1, and the actuator is controlled to carry out third calibration on the fourth error delta x and the fifth error delta z.

In this embodiment, the method is applied to an echelle grating splicing system, which is arranged on a turntable. As shown in fig. 5, the system includes a light source 1, a beam splitter 2, a splicing mechanism 3, a shear plate 6, and an image acquisition unit 8; a plane reflector or a splicing grating is arranged on the splicing mechanism 3; the light beam emitted by the light source is divided into a first light beam and a second light beam through the beam splitter, the first light beam enters the splicing mechanism, and the second light beam is captured by the image acquisition unit after being reflected by the shear plate. A screen 7 of the shear plate is further arranged between the shear plate 6 and the image acquisition unit 8, and the second light beam is reflected by the shear plate 6, enters the screen 7 of the shear plate firstly and is captured by the image acquisition unit 8. The image acquisition unit 8 may be an electronic component with an optical image acquisition function, preferably an optical camera comprising an image sensor.

In this embodiment, as shown in fig. 2, the first error Δ θ Y is a rotation error of the spliced grating around the Y-axis direction, the second error Δ θ X is a rotation error of the spliced grating around the X-axis direction, the third error Δ θ Z is a rotation error of the spliced grating around the Z-axis direction, the fourth error Δ X is a displacement error of the spliced grating along the coordinate X-axis direction, and the fifth error Δ Z is a displacement error of the spliced grating along the coordinate Z-axis direction;

the first error Δ θ x, the second error Δ θ x, the third error Δ θ z, the fourth error Δ x, and the fifth error Δ z satisfy the following formula (1):

wherein λ represents wavelength, α represents grating incident angle, β represents diffraction angle, m represents diffraction order, φ_zIndicating the phase misalignment along the direction of propagation, d phi/dx and d phi/dy indicating the phase gradient of the wavefront.

In general, two gratings are spliced together with errors of five degrees of freedom, namely displacement errors Δ x, Δ y, Δ z along three coordinate axes and rotation errors Δ θ x, Δ θ y and Δ θ z around three coordinate axes. Wherein the influence of the displacement error deltay parallel to the reticle direction on the splicing quality is negligible. When the ideal splicing condition is satisfied, each parameter in the formula (1) satisfies d phi/dx is 0, dφ/dy＝0，φ_z2n pi. As can be seen from the page of formula (1), Δ x and Δ z, and Δ θ x and Δ θ z have complementary relationships, and a single observation is not enough to separate them, so that the error of the above five degrees of freedom is measured and calibrated in a manner of multiple measurements.

As shown in fig. 3, the area 1 and the area 3 in fig. 3 are interference of the light beams B1 and B2 reflected from the front and rear surfaces of the shear plate, respectively, and the area 2 is interference of the light beam B1 reflected from the rear surface of the shear plate and the light beam B2 reflected from the front surface of the shear plate. In the present embodiment, the fringe period includes a period of the interference fringe in the u direction and a period of the interference fringe in the v direction, that is, the calculated fringe period is a fringe period corresponding to the interference fringe formed in the region 2 in fig. 3, and the calculation formula (2) of the periods of the interference fringe in the u and v directions in the region 2 is as follows:

wherein v is_pThe period of the interference fringe in the u direction, u_pIs the period of the interference fringes in the v direction.

In the present embodiment, the fringe displacement Δ Φ 2 and the fringe displacement Δ Φ 1 refer to a displacement of the interference fringe in the u direction, specifically, a displacement of the interference fringe in the u direction in the region 2, and the calculation formula (3) is as follows:

in a practical application scenario, the complete interference period in the u direction cannot always be obtained through calculation of the formulas (2) and (3), and therefore the interference period in the u direction can be indirectly obtained through measuring the slope, and the slope calculation formula (4) is as follows:

the equations in the formula (4) have five unknowns in total, two groups of equations can be obtained by measuring two diffraction orders, all error terms can be solved after the two equations are combined, and the influence of each error on interference fringes is shown in fig. 4. In fig. 4, the interference fringe image (a) shows that the two echelle grating positions currently spliced are error-free, and the fringes are consistent and continuous like the three regions in fig. 3; the interference fringe image (b) shows that the position of the two currently spliced echelle gratings has an error delta x, and the fringes generate dislocation as the region 2 in the figure 3; the interference fringe image (c) shows that the position of the two echelle gratings spliced before has an error delta z, and the fringe of the area 2 in the graph 3 has dislocation; the interference fringe image (d) shows that the position of the two echelle gratings spliced before has an error delta theta x, and the fringe period of the area 2 in the figure 3 changes; the interference fringe image (d) shows that the position of the two echelle gratings spliced before has an error delta theta y, and the fringes of the area 2 in the figure 3 have rotation deviation; the interference fringe image (f) shows that the position of the two echelle gratings spliced in front has an error Δ θ z, and the fringe period of the area 2 in fig. 3 changes.

As shown in fig. 5, the laser beam generated by the light source 1 is changed into a parallel beam by the collimating lens, then a part of the light passes through the beam splitter and enters the first grating 4 and the second grating 5 in the splicing mechanism 3, the other part of the light enters the shear plate 6, and the grating entering the spliced grating also enters the shear plate through the beam splitter 2. The light irradiated on the shear plate 6 is reflected once on the front and rear surfaces thereof, a lateral shear amount is generated between the two reflected lights, and interference fringes are generated at the overlapping portion. If the incident light consists of two adjacent and approximately parallel beams, the interference area is divided into three areas, namely area 1, area 2 and area 3 in fig. 3. The relative preset directions of the two beams of light can influence the fringe pattern of the middle area, so that the error types can be judged by measuring the fringe period and rotating, and the error numerical value can be quantitatively calculated, thereby realizing the strict splicing of the grating. The predetermined orientation is the direction of light propagation, is a spatial direction, and mainly refers to three angles and the relative positions of the light beams.

In this application, splicing mechanism itself is assembled by a plurality of commercial devices and forms, and position and the direction of motion of enterprise all arrange after the accurate calculation. The specific use method is to connect to a computer and input the numerical value to be advanced/retreated in the control software of the system. The 5 control parts in the system respectively correspond to the adjustment of five errors, and the adjusting devices with different errors respectively and independently operate.

In the application, before the grating is installed on the splicing mechanism, the plane reflector needs to be installed firstly to complete the rotation zero calibration of the turntable, and the rotation degree cannot be determined after the zero calibration. The subsequent adjustment of the rotation angle can be more accurate by calibrating the rotation zero point.

In this embodiment, the stripe is generated by the plane mirror, and the width thereof is measured, so that the ratio of the number of pixels corresponding to the stripe period photographed by the camera (i.e., the image capturing unit) to the actual length can be obtained to prepare for the subsequent measurement period. When the reflector is installed, if the current splicing mechanism is already positioned at the rotation zero point, the light beam returns in the original path. If the current splicing mechanism is not located at the rotation zero point, the stripe width is not equal to the theoretical value, and the current splicing mechanism can be located at the rotation zero point by adjusting the position of the current splicing mechanism. Of course, the judgment of whether the position of the splicing mechanism is located at the rotation zero point can be determined by the error smaller than the preset error, for example, the influence of the error within the range of plus or minus 0.5 degrees on the experimental result can be ignored.

In the present embodiment, the first predetermined angle is a littrow angle 64.137 ° of-36 steps, and the second predetermined angle is a littrow angle 67.644 ° of-37 steps. The Littrow angle is determined by the parameters of the grating itself, and is a constant obtained by the calculation of the basic law of optics, which is independent of the experiment itself. The reason for using the littrow angle is that on one hand, the diffracted light of the order can return as it is, and on the other hand, the energy of the light can be concentrated very much, which is beneficial to the measurement.

In this embodiment, an echelle grating of 79gr/mm is selected for experimental verification, and when a 632.8nm light source is used, a-36 level and a-37 level are adopted as working levels according to the energy distribution curve of the grating, and littrow angles of the two levels correspond to 64.137 ° and 67.644 °, respectively. As the reticle density and the light source wavelength change, the selected order and its corresponding angle will also change. Therefore, in other embodiments, when different light sources or echelle gratings are selected, the first preset angle and the second preset angle are adjusted accordingly, and the following conditions are satisfied: (1) the first preset angle is a littrow angle of a working order; (2) the second preset angle is the littrow angle of an adjacent level (+1 or-1) of the working level (i.e. the working level corresponding to the first preset angle), and the specific selected one can be automatically judged by a user by combining factors such as diffraction light intensity and the like.

Referring to fig. 6, in a second aspect, the present application further provides an echelle grating splicing system, where the system is disposed on a turntable, and the system includes a light source, a beam splitter, a splicing mechanism, a shear plate, and an image acquisition unit; the splicing mechanism is provided with a plane reflector or a splicing grating; the light beam emitted by the light source is divided into a first light beam and a second light beam by a beam splitter, the first light beam enters the splicing mechanism, and the second light beam is reflected by the shear plate and then captured by the image acquisition unit; the echelle grating stitching system is for performing the method steps as described in the first aspect of the application.

Specifically, the system includes concatenation mechanism, actuator, connecting piece, rotation control mechanism, the system sets up on revolving stage 12, it places position 11 and second grating and places position 12 to be provided with first grating on the concatenation mechanism, the concatenation grating includes first grating and second grating, first grating set up in position 11 is placed to first grating, the second grating set up in position 12 is placed to the second grating. The actuators include a first actuator 16 and a second actuator 13; the first actuator 16 is used to adjust the error of the first grating and the second actuator 13 is used to adjust the error of the second grating. Preferably, the first actuator 16 and the second actuator 13 are both piezoelectric ceramics.

The rotation control mechanism comprises a first rotation control mechanism 17, a second rotation control mechanism 18 and a third rotation control mechanism 20; the connectors include a first connector 14, a second connector 15, a third connector 19 and a fourth connector 21. The first connecting piece 14 is fixed on the second connecting piece 15, the first actuator 16 is fixed on the first connecting piece 14, the first actuator 16 is fixed on the third connecting piece 19, the third connecting piece 19 is fixed on the third rotation control mechanism 20, and the third rotation control mechanism 20 is fixed on the fourth connecting piece 21. The first rotation control mechanism 17, the second rotation control mechanism 18, and the third rotation control mechanism 20 are respectively used for rotating the mechanical device placed thereon in different directions. For example, the first rotation control means 17 is used to control the roll of the second grating, the second rotation control means 18 is used to control the pitch of the second grating, and the third rotation control means 20 controls the orientation of the first grating.

As shown in fig. 7, the cut-out plate 6 includes a first cut-out plate 61 and a second cut-out plate 62, the screen 7 of the cut-out plate includes a screen 71 of the first cut-out plate and a screen 72 of the second cut-out plate, and the image capturing unit 8 includes a first image capturing unit 81 and a second image capturing unit 82. The working principle of the echelle grating stitching system shown in fig. 7 is similar to that of fig. 5, except that fig. 7 adopts two shearing systems including a shearing plate, a screen of the shearing plate and an image acquisition unit to measure the error of the interference fringes.

The invention provides a splicing method and a splicing system for echelle gratings, which adopt a shearing interference technology, when a beam of light irradiates a shearing plate, primary reflection is respectively generated on the front surface and the rear surface of the shearing plate, a transverse shearing amount is generated between the two beams of reflected light, and an interference fringe is generated on an overlapped part. If the incident light consists of two adjacent and approximately parallel beams, the interference region is divided into three regions. The relative preset direction of the two beams can affect the fringe pattern of the middle area, so the invention judges the error type by measuring the period and rotation corresponding to the interference fringe, and calibrates the error after quantitatively calculating the error value, thereby realizing the strict splicing of the grating.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

The above embodiments of the present invention should not be construed as limiting the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the protection scope of the claims of the present invention.