A grating verticality inspection device and method

Abstract

The present invention relates to the field of replica grating inspection, and relates to a grating verticality inspection device and method, which are used to inspect the verticality of the replica grating scribed line direction and the reference plane, and include a fixed plate, a transmitting device, a loading device, a first slit device and a second slit device, a first photoelectric detection device and a second photoelectric detection device, wherein the transmitting device is arranged at the first end of the fixed plate; the loading device is arranged at the second end of the fixed plate; the first slit device is located between the transmitting device and the loading device, and the second slit device is located in the first-order diffraction direction of the replica grating; the first photoelectric detection device is located at the incident side of the first slit device, and the second photoelectric detection device is located at the exit side of the second slit device. Thus, by comparing the positional relationship between the grating scribed line and the reference plane, the difficult-to-measure scribed line inclination angle is converted into the easy-to-measure dihedral angle between the diffraction plane and the reference plane, thereby effectively improving the measurement accuracy, and further improving the efficiency and yield rate of the replica grating mass production.

Description

Technical Field

[0001] The invention relates to the technical field of replicated grating inspection, and specifically provides a grating verticality inspection device and method. Background Art

[0002] Diffraction grating is an optical element with a periodic relief structure. It can separate the incident polychromatic light into a spectrum according to different wavelengths in the spatial propagation direction. Due to its unique spectroscopic ability, it is widely used in various fields such as spectrum analysis, precision measurement, laser tuning, pulse broadening and compression, etc. However, due to the long production cycle of the master grating, the grating replication method is usually used to make the diffraction grating for mass production.

[0003] Grating replication is a process of using a processed grating as a mold to make a replica. As the number of grating replication generations increases, the grating lines will have slight deviations from the master due to bonding, demoulding, etc. As the number of generations continues to increase, this deviation will gradually increase. Therefore, in actual production, it is particularly important to inspect the deviation of the lines.

[0004] At present, the more mature method for inspecting the line deviation is to measure and observe the grating diffraction wavefront index based on the overall line deviation bending, which can qualitatively analyze the tilt and bending of the grating line. Its main disadvantage is that it cannot fully reflect the relationship between the line and the grating substrate reference plane, and the inspection process is complicated. It is necessary to adjust the grating placement angle and the tilt and pitch position of the incident light, and the dynamic interference fringes need to be adjusted. The detection cycle is long, which is not conducive to the mass production of replicated gratings. In addition, the efficiency and accuracy of detecting the error between the line direction and the reference plane through the collimator are low, which is inconvenient to detect during the grating replication process and it is difficult to achieve accurate detection. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a grating verticality inspection device and method. By comparing the positional relationship between the grating lines and the reference plane, the difficult-to-measure line inclination angle is converted into the easy-to-measure dihedral angle between the diffraction surface and the reference plane, thereby effectively improving the measurement accuracy and further improving the efficiency and yield rate of batch production of replicated gratings.

[0006] An embodiment of the first aspect of the present invention provides a grating verticality inspection device, which is used to inspect the verticality of the replica grating engraving direction and the reference plane, and specifically includes a fixed plate, an emitting device, a loading device, a first slit device and a second slit device, a first photoelectric detection device and a second photoelectric detection device, wherein the fixed plate is arranged in the horizontal direction; the emitting device is arranged at the first end of the fixed plate, and the emitting device is used to emit laser; the loading device is arranged at the second end of the fixed plate, and the loading device is used to place the replica grating; the first slit device and the second slit device are arranged on the fixed plate, the first slit device is located between the emitting device and the loading device, and the second slit device is located in the 1st diffraction direction of the replica grating; the first photoelectric detection device and the second photoelectric detection device are arranged on the fixed plate, the first photoelectric detection device is located in the -1st diffraction direction of the replica grating, and the second photoelectric detection device is located in the 1st diffraction direction of the replica grating.

[0007] Preferably, the emitting device includes an adjusting device, a mirror frame and a laser, the adjusting device is arranged on a fixed plate, and the adjusting device can be raised and lowered in a vertical direction; the mirror frame is arranged above the adjusting device; the laser is used to continuously output laser light of a single wavelength, and the laser is installed on the mirror frame so that the mirror frame can align and adjust the laser.

[0008] Preferably, the mirror frame includes a right-angle connector, a mounting connector and a fine-pitch thread pair, the right-angle connector is connected to the adjustment device, and first threaded holes are provided at both ends of the right-angle connector; a mounting port is provided on the mounting connector, and the laser is clamped in the mounting port, and a second threaded hole corresponding to the first threaded hole is also provided on the mounting connector; the fine-pitch thread pair is passed through the first threaded hole and the second threaded hole, and the fine-pitch thread pair is used to adjust the pitch and yaw direction of the mounting connector relative to the right-angle connector, and a thread pair knob is provided on the fine-pitch thread pair.

[0009] Preferably, the loading device includes a precision lifting device and a loading platform. The precision lifting device is connected to the fixed plate and can be lifted and lowered in the vertical direction. The loading platform is connected above the precision lifting platform and is used to place the replica grating.

[0010] Preferably, the first slit device includes an adjustment device and a light shield, the adjustment device is arranged on a fixed plate, and the adjustment device can be lifted and lowered in a vertical direction; the light shield is connected above the adjustment device, an incident slit is provided on the light shield, and a slit knob is also provided on the light shield, and the slit knob is used to adjust the size of the incident slit. The second slit device includes an adjustment device and a light shield, the adjustment device is arranged on a fixed plate, and the adjustment device can be lifted and lowered in a vertical direction; the light shield is connected above the adjustment device, a diffraction slit is provided on the light shield, and a slit knob is also provided on the light shield, and the slit knob is used to adjust the size of the diffraction slit.

[0011] Preferably, the first photoelectric detection device or the second photoelectric detection device includes an adjusting device and a photoelectric detector, the adjusting device is arranged on the fixed plate, and the adjusting device can be raised and lowered in the vertical direction; the photoelectric detector is connected above the adjusting device.

[0012] Preferably, the adjustment device includes an adjustment support, a support rod and a locking screw. A magnetic base is provided at the bottom of the adjustment support, and a fork-type pressure plate is provided on the magnetic base. The fork-type pressure plate is used to connect to the fixed plate. A third threaded hole is also provided on the adjustment support; the support rod is slidably inserted in the adjustment support; the locking screw is screwed into the third threaded hole, and the locking screw is used to apply a clamping force to the support rod.

[0013] The embodiment of the second aspect of the present invention provides a grating verticality inspection method, which specifically includes:

[0014] S102: Assembling the grating verticality inspection device provided according to the embodiment of the first aspect;

[0015] S104: placing a triangular prism on the object-carrying device so that the triangular prism and the emitting device are at the same height, and adjusting the triangular prism until the reflected light passing through the triangular prism passes through the second slit device and is received by the second photoelectric detection device, that is, the first slit device and the second slit device are located on the reference plane;

[0016] S106: placing the replica grating on the object-carrying device, adjusting the replica grating until the 0th order diffracted light coincides with the incident light, and determining whether the 1st order diffracted light passes through the second slit device.

[0017] Preferably, the x and y rectangular coordinate systems are established with the cross section of the replica grating line direction and the reference plane, and the height difference Δ between the diffracted light and the second slit device on the y axis is measured respectively. y , the distance between the diffracted light and the incident light on the x-axis Δ x , the dihedral angle between the diffraction surface of the replica grating and the reference surface θ for:

[0018] θ = arctan(Δ y / Δ x ),

[0019] Among them, the angle θ This is the tilt angle of the replicated grating lines.

[0020] Compared with the prior art, the present invention can achieve the following beneficial effects: a grating verticality inspection device, used for inspecting the verticality of the replica grating engraving direction and the reference plane, specifically comprising a fixed plate, an emitting device, a loading device, a first slit device and a second slit device, a first photoelectric detection device and a second photoelectric detection device, the fixed plate is arranged in the horizontal direction; the emitting device is arranged at the first end of the fixed plate, and the emitting device is used to emit laser; the loading device is arranged at the second end of the fixed plate, and the loading device is used to place the replica grating; the first slit device and the second slit device are arranged on the fixed plate, the first slit device is located between the emitting device and the loading device, and the second slit device is located in the 1st diffraction direction of the replica grating; the first photoelectric detection device and the second photoelectric detection device are arranged on the fixed plate, the first photoelectric detection device is located in the -1st diffraction direction of the replica grating, and the second photoelectric detection device is located in the 1st diffraction direction of the replica grating.

[0021] Therefore, based on the diffraction characteristics when the laser is vertically incident on the grating, the present invention cleverly converts the measurement of the grating line inclination angle into the measurement of the dihedral angle between the diffraction surface and the reference plane, and through the geometric relationship between the first-order diffraction spot, the slit and the dihedral angle, the difficult-to-measure line inclination angle is converted into an easy-to-measure distance problem, that is, the dihedral angle between the diffraction surface and the reference plane is calculated by measuring the distance, which effectively improves the measurement accuracy, thereby improving the efficiency and yield rate of mass production of replica gratings.

[0022] Among them, the grating verticality inspection device provided by the present invention has a small size, a simple structure, is easy to operate and has high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of a grating verticality inspection device provided according to an embodiment of the first aspect of the present invention;

[0024] Figure 2 is a schematic diagram of an optical path of a grating verticality inspection device provided according to an embodiment of the first aspect of the present invention;

[0025] Figure 3 is a schematic diagram of the principle of a grating verticality inspection device provided according to an embodiment of the first aspect of the present invention;

[0026] Figure 4 It is a flow chart of a grating verticality inspection device provided according to an embodiment of the second aspect of the present invention.

[0027] Reference numerals include:

[0028] 1 fixing plate, 2 emitting device, 21 adjusting device, 211 adjusting support, 212 magnetic base, 213 supporting rod, 214 locking screw, 221 right angle connector, 222 mounting connector, 223 threaded sub-knob, 23 laser, 3 loading device, 31 precision lifting device, 32 loading stage, 41 first slit device, 42 second slit device, 43 light shielding plate, 431 incident slit, 432 diffraction slit, 433 slit knob, 51 first photoelectric detection device, 52 second photoelectric detection device, 53 photoelectric detector, 6 replica grating. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same modules are represented by the same reference numerals. In the case of the same reference numerals, their names and functions are also the same. Therefore, the detailed description thereof will not be repeated.

[0030] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0031] Refer to the following Figures 1 to 4 A grating verticality inspection device and method provided according to some embodiments of the present invention are described, wherein the directions of the first end and the second end are as marked in the figure.

[0032] like Figure 1 to Figure 2As shown, a grating verticality inspection device provided according to an embodiment of the first aspect of the present invention is used to inspect the verticality of the replica grating 6 engraved direction and the reference plane, and specifically includes a fixed plate 1, a transmitting device 2, a loading device 3, a first slit device 41 and a second slit device 42, a first photoelectric detection device 51 and a second photoelectric detection device 52. The fixed plate 1 is arranged in the horizontal direction, which is the application area of ​​the replica grating 6 verticality inspection device. The transmitting device 2 is arranged at the first end of the fixed plate 1, and the transmitting device 2 is used to emit laser. The loading device 3 is arranged at the second end of the fixed plate 1, and the loading device 3 is used to place the replica grating 6. The first slit device 41 and the second slit device 42 are arranged on the fixed plate 1, and the first slit device 41 is located between the transmitting device 2 and the loading device 3, so that the laser emitted by the transmitting device 2 passes through the first slit device 41, forms a laser beam incident on the surface of the replica grating 6 and generates diffraction phenomenon; the second slit device 42 is located in the 1st order diffraction direction of the replica grating 6, and is used to observe the specific position of the 0th order diffraction of the replica grating 6. The first photodetection device 51 and the second photodetection device 52 are arranged on the fixed plate 1 for detecting the optical feedback signal; the first photodetection device 51 is located in the -1st order diffraction direction of the replica grating 6, and the second photodetection device 52 is located in the 1st order diffraction direction of the replica grating 6, and is arranged on the exit side of the second slit device 42; wherein, the first photodetection device 51 and the second photodetection device 52 are respectively connected to an oscilloscope for measuring and reading the optical feedback signal.

[0033] Therefore, by comparing the positional relationship between the grating lines and the reference plane, the difficult-to-measure line inclination angle is converted into the easy-to-measure dihedral angle between the diffraction surface and the reference plane, which effectively improves the measurement accuracy and thereby improves the efficiency and yield rate of mass production of the replica grating 6.

[0034] Preferably, the fixing plate 1 is made of hard aluminum alloy, and connectors are evenly spaced in a matrix on the fixing plate 1 for installing upper equipment to facilitate quantitative analysis when checking the perpendicularity between the direction of the replica grating 6 and the reference plane.

[0035] like Figure 1 As shown, the emitting device 2 includes an adjusting device 21, a mirror frame and a laser 23. The adjusting device 21 is arranged on the fixing plate 1. At this time, the setting position of the adjusting device 21 can be regarded as the position of the emitting device 2, so as to quantitatively analyze and calculate the perpendicularity between the engraved line direction of the replica grating 6 and the reference plane. The adjusting device 21 can be raised and lowered in the vertical direction to adjust the height of the laser 23 in the vertical direction. The mirror frame is arranged above the adjusting device 21 to install the laser 23 and adjust the alignment of the laser 23. The laser 23 is used to continuously output a single wavelength laser.

[0036] Preferably, the laser 23 uses a small semiconductor laser 23 or a multi-band laser 23, which outputs a single-wavelength laser of a point-shaped light spot in a continuous working mode as a light source, and is collimated after being fixed and adjusted by the frame.

[0037] like Figure 1 As shown, the mirror frame includes a right-angle connector 221, a mounting connector 222 and a fine-pitch thread pair. The bottom of the right-angle connector 221 is connected to the adjustment device 21, and first threaded holes are provided at both ends of the right-angle connector 221; a mounting port is provided on the mounting connector 222, and the laser 23 is mounted in the mounting port. The mounting connector 222 is also provided with a second threaded hole corresponding to the first threaded hole; the fine-pitch thread pair is penetrated through the first threaded hole and the second threaded hole, and the fine-pitch thread pair is used to adjust the pitch and yaw directions of the mounting connector 222 relative to the right-angle connector 221, so as to achieve precise adjustment of the angle of the laser 23 along the pitch direction and yaw direction. A thread pair knob 223 is provided on the fine-pitch thread pair, so that the fine-pitch thread pair can be adjusted by the thread pair knob 223.

[0038] like Figure 1 As shown, the loading device 3 includes a precision lifting device 31 and a loading platform 32. The precision lifting device 31 is connected to the fixed plate 1. The precision lifting device 31 can accurately adjust the lifting height in the vertical direction, so as to adjust the position of the replica grating 6 in the vertical direction; the loading platform 32 is connected above the precision lifting platform. The loading platform 32 is used to place the replica grating 6 so that the replica grating 6 can be located in a required posture.

[0039] In some possible embodiments, the stage 32 may also be a two-dimensional turntable for performing two-dimensional adjustment on the grating to be measured.

[0040] like Figure 1 As shown, the first slit device 41 includes an adjustment device 21 and a light shielding plate 43. The adjustment device 21 is arranged on the fixed plate 1 and can be lifted and lowered in the vertical direction to adjust the height of the light shielding plate 43 in the vertical direction. The light shielding plate 43 is connected to the upper part of the adjustment device 21. An incident slit 431 is provided on the light shielding plate 43. A slit knob 433 is also provided on the light shielding plate 43. The slit knob 433 is used to adjust the size of the incident slit 431. By adjusting the opening width of the incident slit 431, the laser light emitted by the laser 23 is separated into laser beams of appropriate sizes, so that diffraction occurs when reaching the surface of the replica grating 6.

[0041] like Figure 1As shown, the second slit device 42 includes an adjustment device 21 and a light shielding plate 43. The adjustment device 21 is arranged on the fixing plate 1 and can be lifted and lowered in the vertical direction to adjust the height of the light shielding plate 43 in the vertical direction. The light shielding plate 43 is connected to the top of the adjustment device 21. A diffraction slit 432 is provided on the light shielding plate 43. A slit knob 433 is also provided on the light shielding plate 43. The slit knob 433 is used to adjust the size of the diffraction slit 432. By adjusting the opening width of the diffraction slit 432, it can be determined that the incident light and the diffracted light are on the same plane.

[0042] like Figure 1 As shown, the first photoelectric detection device 51 or the second photoelectric detection device 52 includes an adjusting device 21 and a photoelectric detector 53. The adjusting device 21 is arranged on the fixed plate 1 and can be raised and lowered in the vertical direction. The photoelectric detector 53 is connected above the adjusting device 21, so that the adjusting device 21 can also be used to adjust the height of the photoelectric detector 53 in the vertical direction.

[0043] The photodetector 53 here can be a medium- or low-speed photodetector 53 or a linear array CCD device, which is used to read the detected light signal.

[0044] like Figure 1 As shown, the adjustment device 21 includes an adjustment support 211, a support rod 213 and a locking screw 214. A through-type magnetic base 212 is provided at the bottom of the adjustment support 211, and a fork-type pressure plate is provided on the magnetic base 212. The fork-type pressure plate is used to connect to the fixed plate 1, so as to better fix the adjustment device 21 on the fixed plate 1. The support rod 213 is slidably inserted in the adjustment support 211, and is used to connect to the support frame, the first slit device 41, the second slit device 42, the first photoelectric detection device 51 and the second photoelectric detection device 52, and drives the above devices to rise and fall in the vertical direction. A third threaded hole is also provided on the adjustment support 211, and a locking screw 214 is screwed into the third threaded hole. The locking screw 214 is used to apply a pressing force to the support rod 213 to facilitate positioning of the support rod 213.

[0045] When installing the adjustment support 211, first use the magnetism of the magnetic base 212 to temporarily position the adjustment support 211 on the hard aluminum alloy fixing plate 1; when the adjustment support 211 is in a suitable position, press the fork-type pressure plate on the connecting piece to fasten the adjustment support 211 to the hard aluminum alloy fixing plate 1.

[0046] The locking screw 214 is provided with a hand-tightening knob for manually adjusting the support rod 213. Preferably, a double-line contact is adopted between the support rod 213 and the adjustment support 211, so that when the locking screw 214 is adjusted, the connection between the support rod 213 and the adjustment support 211 is more stable.

[0047] The inspection principle of the grating verticality inspection device provided by the present invention is as follows: Figure 3 As shown in the optical path diagram.

[0048] The single wavelength laser emitted by the laser 23 passes through the incident slit 431 after being collimated, and is vertically incident on the plane of the replica grating 6 to be tested. According to the diffraction characteristics of the grating, the diffraction plane and the direction of the scribed lines of the replica grating 6 are perpendicular to each other, so the diffraction plane corresponding to the unbiased scribed lines is used as the reference plane. Since the corresponding 0th order diffraction light is always emitted in the direction of the incident light when the laser is incident vertically, when the scribed lines have a certain inclination angle θ When , the corresponding diffraction plane will rotate the same angle with the direction of the 0th order diffraction light as the axis θ By measuring the dihedral angle between the diffraction surface of the inclined grating and the reference plane, the inclination angle of the replica grating 6 can be obtained.

[0049] Specifically, through the geometric relationship between the first-order diffraction spot, the slit and the dihedral angle, the line tilt angle can be converted into an easily measurable distance, that is, the dihedral angle between the diffraction surface and the reference surface can be calculated by measuring the distance. The above method can be used to qualitatively analyze the tilt degree of the line by visually observing the height difference between the first-order diffraction spot and the slit, and the line tilt angle can be quantitatively calculated by substituting the measured data into the formula.

[0050] Next, a specific embodiment of a grating verticality inspection device is given. Figure 1 As shown:

[0051] First, a small semiconductor laser 23 is used as the light source to output a single-wavelength laser with a point-shaped spot in a continuous working mode, wherein the central wavelength of the output laser is 650±10nm and the power is 40mW. An M4 nylon head screw is used to fasten the laser 23 to the mounting port, so that the laser 23 can collimate the incident laser after being fixed and adjusted by the frame. The end surface of the threaded pair knob 223 is provided with an inner hexagon hole, which can be adjusted with a 2mm inner hexagon wrench, so that by adjusting the two fine-pitch thread pairs, the angle of the laser 23 in the pitch direction and the yaw direction can be precisely adjusted, and the single-axis adjustment amount is ±4°.

[0052] Secondly, an M6 threaded countersunk hole or an M4 threaded hole can be opened on the side of the frame to fix the frame on the adjustment device 21. Specifically, the locking screw 214 of the adjustment device 21 adopts a delicate hexagon socket M6 screw with elastic knurling, which is used to apply a pre-tightening force to the support rod 213. A hand-tightening knob is provided on the locking screw 214 to facilitate adjustment and positioning. Among them, a 5mm hexagonal wrench can be used to reinforce the clamping of the hand-tightening knob. A Ø12.7mm support rod 213 is used to penetrate the adjustment support 211. The support rod 213 and the adjustment support 211 adopt double-line contact, so that the connection between the support rod 213 and the adjustment support 211 is more stable.

[0053] Next, the height and width of the incident slit 431 and the diffraction slit 432 are adjusted respectively, so that the laser output by the laser 23 is incident on the triangular prism through the incident slit 431, wherein the height range of the incident slit 431 and the diffraction slit 432 is 0-10mm, the length is 80mm, and the size of the light shield 43 is 130×104×16.5mm. The wavelength range of the photodetector 53 is 400-800nm, and the bandwidth is 10KHz.

[0054] like Figure 4 As shown, a grating verticality inspection method provided according to an embodiment of the second aspect of the present invention is applied to inspect the verticality between the grating line direction of the replica grating 6 and the reference surface, specifically comprising:

[0055] S102: Assemble the grating verticality inspection device provided according to the embodiment of the first aspect of the present invention.

[0056] Among them, after the grating verticality inspection device is assembled, it is necessary to use a mirror frame to level the laser 23, adjust the precision lifting device 31 and the stage 32 so that the replica grating 6 can be located on the same horizontal plane as the laser 23, adjust the second slit device 42 and the second photoelectric detection device 52 to be located in the direction of the 1st order diffraction light, and the first photoelectric detection device 51 to be located in the direction of the -1st order diffraction light.

[0057] S104: Place the triangular prism on the loading device 3 so that the triangular prism and the emitting device 2 are at the same height, and adjust the triangular prism until the reflected light passing through the triangular prism passes through the second slit device 42 and is received by the second photoelectric detection device 52, that is, the first slit device 41 and the second slit device 42 are located on the reference plane.

[0058] Specifically, before inspecting the replica grating 6, the triangular prism is first placed on the stage 32, and the stage 32 is adjusted so that the triangular prism and the laser light source are at the same height. Then the triangular prism is fine-tuned, and after the triangular prism splits the light, it is rotated at a certain angle to ensure that the reflected light passing through the triangular prism can be incident on the diffraction slit 432. At this time, the height of the second slit device 42 is adjusted so that the reflected light just passes through the diffraction slit 432 and hits the second photodetector 53, thereby ensuring that the incident slit 431 and the diffraction slit 432 are in the same plane, that is, the reference plane.

[0059] S106 : placing the replica grating 6 on the object-carrying device 3 , adjusting the replica grating 6 until the 0th-order diffracted light coincides with the incident light, and determining whether the 1st-order diffracted light passes through the second slit device 42 .

[0060] Specifically, after adjusting the incident slit 431 and the diffraction slit 432 to determine the reference plane, the replica grating 6 to be measured is placed on the stage 32, and the replica grating 6 to be measured is finely adjusted so that the 0th order diffraction light coincides with the incident light to reduce the influence of the grating surface error on the measurement result. At this time, the 1st order diffraction light of the replica grating 6 to be measured will hit the diffraction slit 432, and the signal output by the second photodetector 53 is used to determine whether the 1st order diffraction light spot passes through the diffraction slit 432. If the 1st order diffraction light spot just passes through the diffraction slit 432, it indicates that the 0th order diffraction light and the 1st order diffraction light of the grating are both on the reference plane, that is, the diffraction surface of the replica grating 6 to be measured coincides with the reference plane, and the lines of the replica grating 6 to be measured are not biased. If the 1st-order diffraction spot does not pass through the diffraction slit 432, it means that the 0th-order diffraction light and the 1st-order diffraction light of the grating are higher or lower than the diffraction slit 432, that is, the diffraction surface of the measured replica grating 6 does not coincide with the reference surface, and the lines of the measured replica grating 6 are tilted.

[0061] like Figure 3 As shown, in order to quantitatively analyze the tilt angle of the measured replica grating 6, an x ​​and y rectangular coordinate system is established with the replica grating 6 and the cross section of the reference plane, and the height difference Δ between the diffraction spot on the light shielding plate 43 of the second slit device 42 and the diffraction slit 432 on the y axis is measured respectively. y , the distance Δ on the x-axis between the diffraction spot on the light blocking plate 43 of the second slit device 42 and the diffraction point on the replica grating 6 x， Dihedral angle between the diffraction surface of the replica grating 6 with inclined lines and the reference surface θ for:

[0062] θ = arctan(Δ y / Δ x ),

[0063] Among them, the angle θ This is the inclination angle of the replica grating 6 lines.

[0064] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. Those skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

[0065] The above specific implementations of the present invention do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A grating verticality inspection device, used for inspecting the verticality between the grating line direction of a replica grating (6) and a reference surface, characterized in that: include: A fixing plate (1), wherein the fixing plate (1) is arranged in a horizontal direction; An emitting device (2), the emitting device (2) being arranged at a first end of the fixing plate (1), and the emitting device (2) being used for emitting laser light; A loading device (3), the loading device (3) being arranged at the second end of the fixing plate (1), the loading device (3) being used for placing the replica grating (6); A first slit device (41) and a second slit device (42), wherein the first slit device (41) and the second slit device (42) are arranged on the fixing plate (1), the first slit device (41) is located between the emitting device (2) and the object-carrying device (3), and the second slit device (42) is located in the first-order diffraction direction of the replica grating (6); A first photodetection device (51) and a second photodetection device (52), wherein the first photodetection device (51) and the second photodetection device (52) are arranged on the fixed plate (1), the first photodetection device (51) is located in the -1st order diffraction direction of the replica grating (6), and the second photodetection device (52) is located in the 1st order diffraction direction of the replica grating (6).

2. The grating verticality inspection device according to claim 1, characterized in that: The transmitting device (2) comprises: An adjusting device (21), wherein the adjusting device (21) is arranged on the fixing plate (1), and the adjusting device (21) can be raised and lowered in a vertical direction; A frame, the frame being arranged above the adjusting device (21); A laser (23) is used for continuously outputting laser light of a single wavelength. The laser (23) is mounted on the mirror frame so that the mirror frame can perform collimation adjustment on the laser (23).

3. The grating verticality inspection device according to claim 2, characterized in that: The frame comprises: A right-angle connecting piece (221), the right-angle connecting piece (221) being connected to the adjusting device (21), and first threaded holes being formed at both ends of the right-angle connecting piece (221); A mounting connection piece (222), wherein the mounting connection piece (222) is provided with a mounting opening, the laser (23) is mounted on the mounting opening, and the mounting connection piece (222) is also provided with a second threaded hole corresponding to the first threaded hole; A fine-pitch thread pair, the fine-pitch thread pair being inserted through the first threaded hole and the second threaded hole, the fine-pitch thread pair being used to adjust the pitch and yaw directions of the mounting connector (222) relative to the right-angle connector (221), and a thread pair knob (223) being provided on the fine-pitch thread pair.

4. The grating verticality inspection device according to claim 1, characterized in that: The object carrying device (3) comprises: A precision lifting device (31), the precision lifting device (31) is connected to the fixing plate (1), and the precision lifting device (31) can be lifted and lowered in a vertical direction; The object platform (32) is connected to the top of the precision lifting platform, and the object platform (32) is used to place the replica grating (6).

5. The grating verticality inspection device according to claim 1, characterized in that: The first slit device (41) or the second slit device (42) comprises: An adjusting device (21), wherein the adjusting device (21) is arranged on the fixing plate (1), and the adjusting device (21) can be raised and lowered in a vertical direction; A light shield (43), the light shield (43) being connected to the top of the adjustment device (21), the light shield (43) being provided with an incident slit (431) or a diffraction slit (432), and the light shield (43) being further provided with a slit knob (433), the slit knob (433) being used to adjust the size of the incident slit (431) or the diffraction slit (432).

6. The grating verticality inspection device according to claim 1, characterized in that: The first photoelectric detection device (51) or the second photoelectric detection device (52) comprises: An adjusting device (21), wherein the adjusting device (21) is arranged on the fixing plate (1), and the adjusting device (21) can be raised and lowered in a vertical direction; A photoelectric detector (53), wherein the photoelectric detector (53) is connected above the adjusting device (21).

7. The grating verticality inspection device according to any one of claims 2, 5 or 6, characterized in that: The regulating device (21) comprises: An adjustment support (211), wherein a magnetic base (212) is provided at the bottom of the adjustment support (211), a fork-type pressing plate is provided on the magnetic base (212), and the fork-type pressing plate is used to be connected to the fixing plate (1), and a third threaded hole is also provided on the adjustment support (211); A support rod (213), wherein the support rod (213) is slidably inserted into the adjustment support (211); A locking screw (214), wherein the locking screw (214) is screwed into the third threaded hole, and the locking screw (214) is used to apply a pressing force to the support rod (213).

8. A method for inspecting grating verticality, characterized in that: include: Assembling the grating verticality inspection device according to claim 1; Placing a triangular prism on the object-carrying device (3) so that the triangular prism and the emitting device (2) are located at the same height, and adjusting the triangular prism until the reflected light passing through the triangular prism passes through the second slit device (42) and is received by the second photoelectric detection device (52), that is, the first slit device (41) and the second slit device (42) are located on a reference plane; The replica grating (6) is placed on the object carrier (3), and the replica grating (6) is adjusted until the 0th order diffracted light coincides with the incident light, and it is determined whether the 1st order diffracted light passes through the second slit device (42).

9. The grating verticality inspection method according to claim 8, characterized in that: An x and y rectangular coordinate system is established with the direction of the replica grating (6) and the cross section of the reference plane, and the height difference Δ between the diffracted light and the second slit device (42) on the y axis is measured respectively. y , the distance Δ between the diffracted light and the incident light on the x-axis x , the dihedral angle between the diffraction surface of the replica grating (6) and the reference surface θ for: θ = arctan(Δ y / Δ x ), Among them, the angle θ That is, the inclination angle of the lines of the replica grating (6).

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