Coaxial self-centering tunable reflection grating diffraction performance testing device

Abstract

The invention discloses a coaxial self-centering tunable reflection grating diffraction performance testing device. Comprising a supporting device, a stretching device for stretching a flexible grating sample, a rotating device for coaxially changing and measuring incident and emergent angles, a light source device for fixing and adjusting an incident laser, and a receiving device for fixing and adjusting the position and orientation of a receiving screen or a camera, wherein the rotating device is connected with the light source device and the receiving device, the stretching device is fixedly arranged on the supporting device, and self-centering is achieved by adjusting the relative position. The device is compact in structure, moderate in size, simple to operate and accurate in test result. The grating is fixed and stretched by using a mechanical device, the tunability of the grating is ensured, the design of a rotating shaft can change the incident laser and the included angle between the receiving device and the grating at the same time, and the device also can change the parameters such as the incident distance, the receiving distance and the orientation. When the position of a test sample is self-centered, six-degree-of-freedom experimental test is realized, and the device has higher adaptability due to the adjustment design of different positions.

Description

Technical Field

[0001] The invention relates to a technology in the field of optical testing, in particular to a coaxial self-centering tunable reflection grating diffraction performance testing device. Background Art

[0002] The existing grating diffraction test bench has problems such as difficulty in adapting to the stretching requirements of flexible gratings, difficulty in adapting to the detection range of wide-angle diffraction gratings, difficulty in quickly and accurately adjusting the positional relationship between the light source, grating and receiving device, and difficulty in accurately measuring the geometric parameters that affect the diffraction performance of the grating. The existing Fizeau type synchronous phase-shifting interference test technology uses the parallel light generated by beam expansion and splitting to detect the three-order diffraction fringes generated by the transmission grating, but the existing technology cannot measure non-paraxial diffraction fringes with larger diffraction angles, cannot control optical parameters such as the incident angle, and cannot adapt to the grating constant adjustment requirements of flexible gratings. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention proposes a coaxial self-centering tunable reflection grating diffraction performance test device, which is characterized by compact structure, moderate volume, simple operation and accurate test results. The grating is fixed and stretched by a mechanical device to ensure the tunability of the grating. The design of the rotating axis can simultaneously change the angle between the incident laser, the receiving device and the grating. At the same time, the device can also change parameters such as the incident distance, the receiving distance and the orientation. While achieving self-centering of the test sample position, up to six degrees of freedom experimental tests are achieved. The adjustment design at different positions also makes the device more adaptable.

[0004] The present invention is achieved through the following technical solutions:

[0005] The present invention relates to a coaxial self-centering tunable reflection grating diffraction performance testing device, comprising: a supporting device, a stretching device for stretching a flexible grating sample, a rotating device for coaxially changing and measuring the incident and exit angles, a light source device for fixing and adjusting an incident laser, and a receiving device for fixing and adjusting the position and orientation of a receiving screen or a camera, wherein: the rotating device is respectively connected to the light source device and the receiving device, the stretching device is fixedly arranged on the supporting device, and self-centering is achieved by adjusting the relative positions.

[0006] The stretching device comprises: a sample clamp and a stretching platform, wherein: the sample clamp is fixed on the stretching platform through a stopper or a thread, and the stretching platform is arranged on the supporting device.

[0007] The supporting device includes: a triangular bracket, a vertical adapter plate and a vertical pad, wherein: two triangular brackets are arranged opposite to each other, the vertical adapter plate is fixedly connected to the triangular bracket by threads, and the through grooves on the vertical pad enable the stretching table to be fixed on the vertical adapter plate at different heights and horizontal positions, thereby reaching the same height as the light source, while avoiding misalignment caused by processing errors.

[0008] The rotating device includes: an adapter plate, a hollow rotating table, a plug bolt, a fixing frame, a bearing screw mechanism and an arc scale, wherein: the hollow rotating table is fixed to the optical platform through the adapter plate, the plug bolt is connected to the adapter plate through a thread and is coaxially arranged with the hollow rotating table, two fixing frames are fixedly arranged on the rotating part of the hollow rotating table to constrain the angle and distance of the receiving device relative to the flexible grating while providing reliable fixation, the vertical bearing seat of the bearing screw mechanism is arranged on the optical axis position of the plug bolt and axially positioned by a limit ring, and the incident height of the laser can be adjusted by modifying the position of the limit ring, a pair of screws of the bearing screw mechanism are arranged in the mounting hole of the vertical bearing seat and are connected to the light source device, thereby constraining the angle and distance of the light source device relative to the flexible grating and providing reliable fixation, and the arc scale is fixed on the optical platform for reading the laser incident angle.

[0009] The light source device comprises: a laser, an adapter block and a height adjustment bolt, wherein: the laser is connected to the adapter block through a bolt and a hand-tightened nut, and its height and angle can be manually adjusted through the height adjustment bolt; the adapter block is passed through by a lead screw and is locked by a double nut, so that the distance between the light source and the sample can be adjusted.

[0010] The receiving device includes: a distance adjustment block and a rotating table, a rotating bracket, a dovetail groove linear guide and a light receiving device arranged thereon in sequence, wherein: the distance adjustment block is fixed to the fixed bracket by bolts and is directly opposite to the sample to be tested, and the distance adjustment of the light receiving device relative to the flexible grating is achieved by sliding on the fixed bracket. The rotating table is used to accurately adjust the orientation angle of the light receiving device, and the dovetail groove linear guide is fixed on the rotating table by the rotating bracket to horizontally adjust the light receiving device.

[0011] The light receiving device is implemented as a camera or a light screen. When a camera is used, the detection of diffraction fringes on a flat light screen is achieved by shooting and synthesizing by translation, or the detection of diffraction fringes on a circular arc light screen is achieved by shooting and synthesizing by rotating around a central axis. When a light screen is used, direct observation of the diffraction fringes on the flat light screen is achieved through the principle of diffuse reflection. Technical Effects

[0012] The present invention fixes a stretching device and a rotating device relatively to an optical platform through a supporting device, and a light source device and a receiving device are respectively connected to two ends of the rotating device. The assembly realizes new functions of self-centering stretching adjustment of a tunable reflective grating, coaxial adjustment of the positions of the light source device and the receiving device around the grating, and precise measurement of incident and output parameters.

[0013] Compared with the prior art, the present invention realizes the fixation and self-centering stretching of the reflective flexible grating; realizes the non-paraxial diffraction performance test of the reflective grating; has multi-degree-of-freedom parameter adjustment, and constrains unnecessary degrees of freedom in the performance test through a coaxial design; the measuring device is replaceable, realizing the dual experimental requirements of direct observation of the light screen and precise measurement of the camera. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the device when the stretching table is placed horizontally and the receiver is a camera;

[0015] Figure 2 It is a structural schematic diagram of the device when the stretching table is placed horizontally and the receiver is a light screen;

[0016] Figure 3 It is a structural schematic diagram of the device when the stretching table is placed vertically and the receiver is a light screen;

[0017] Figure 4 (a) is a schematic diagram of a stretching device of the present invention;

[0018] Figure 5 is a schematic diagram of the support device (b) of the present invention;

[0019] Figure 6 is a schematic diagram of the rotating device (c) of the present invention;

[0020] Figure 7 is a cross-sectional schematic diagram of the rotating device (c) of the present invention, in which the cross-sectional diagram is cut along the axis to show the installation position relationship;

[0021] Figure 8 is a schematic diagram of a light source device (d) of the present invention;

[0022] Fig. 9 is a schematic diagram of a receiving device (e) of the present invention;

[0023] In the figure: optical platform 1, tripod bracket 2, vertical adapter plate 3, vertical pad 4, stretching table 5, sample fixture 6, adapter plate 7, hollow rotating table 8, vertical bearing seat 9, plug bolt 10, short fixing frame 11, long fixing frame 12, screw 13, clamping block 14, ruler 15, pointer 16, laser adapter block 17, height adjustment bolt 18, laser 19, hand nut 20, distance adjustment block 21, rotating table 22, dovetail groove linear guide 23, camera bracket 24, camera 25, slider 26, flange 27, cross optical axis adapter 28, optical axis 29, bolt 30, light screen 31, rotating bracket 32. DETAILED DESCRIPTION

[0024] like Figure 1-Figure 3 As shown, this embodiment relates to a coaxial self-centering tunable reflection grating diffraction performance testing device, comprising: an optical platform 1 and a supporting device b, a rotating device c, a light source device d for measuring and adjusting the light source angle and the incident distance, and a receiving device e for measuring and adjusting the distance, angle and orientation of the receiving screen and the camera, respectively arranged thereon, wherein: the rotating device c is connected to the light source device d and the receiving device e, respectively, and a stretching device a for fixing the flexible grating and self-centering stretching is provided on the supporting device b.

[0025] The optical platform 1 is a rectangular bottom plate with an array of threaded holes on its surface.

[0026] like Figure 1 and Figure 4 As shown, the stretching device a comprises: a sample fixture 6 and a stretching platform 5, wherein: the sample fixture 6 is fixed to the stretching platform 5 by a stopper or a thread, and the stretching platform 5 is arranged on the supporting device b.

[0027] The stretching table 5 is a manual slide table driven by positive and negative threaded rods. By turning the knob, two symmetrical sliders of the slide table slide toward the middle or both sides at the same time. The sliders are provided with blocks and threads.

[0028] The stretching platform 5 is provided with a scale so that the stretching size can be measured and controlled.

[0029] The sample fixture 6 is composed of four long strip-shaped sheet clamps, which are used to fix the flexible grating sample on the stretching table. The two ends of the sample are clamped between two sheet clamps respectively and clamped with bolts.

[0030] like Figure 1 and Figure 5As shown, the supporting device b comprises: a tripod bracket 2, a vertical adapter plate 3 and a vertical pad 4, wherein: two tripod brackets 2 are relatively arranged on the optical platform 1, the vertical adapter plate 3 is fixedly connected to the tripod bracket 2 by threads, and the through grooves on the vertical pad 4 enable the stretching table 5 to be fixed on the vertical adapter plate 3 at different heights and horizontal positions, so as to reach the same height as the light source, while avoiding misalignment caused by processing errors.

[0031] The tripod bracket 2 is composed of two triangular blocks placed in parallel at a certain distance, with the short right-angled sides thereof being fixed to the optical platform by bolts, and the long right-angled sides thereof being fixed to the vertical adapter plate by bolts.

[0032] The vertical adapter plate 3 has four through slots in the middle for fixing nuts, and is designed so that the horizontal position of the stretching table can be adjusted within a certain range.

[0033] The vertical adapter plate 3 is provided with threaded holes for vertically installing the stretching table, which increases the compatibility of the stretching table 5 for vertical stretching experiments.

[0034] The vertical pad 4 serves as a pad between the stretching table and the adapter plate. Its flange provides a reference for the installation of the stretching table, and its through groove allows the vertical position of the stretching table to be adjusted within a certain range. Its thickness is designed to correct the deviation of the stretching table relative to the central axis.

[0035] like Figure 1 and Figure 6 As shown, the rotating device c comprises: an adapter plate 7, a hollow rotating table 8, a plug bolt 10, a fixing frame 11, 12, a vertical bearing seat 9 and a screw 13, wherein: the hollow rotating table 8 is fixed to the optical platform 1 through the adapter plate 7, the plug bolt 10 is threadedly connected to the adapter plate 7 and is coaxially arranged with the hollow rotating table 8, two fixing frames 11, 12 are fixedly arranged on the rotating part of the hollow rotating table 8 for constraining the angle and distance of the receiving device relative to the flexible grating while providing reliable fixation, the vertical bearing seat 9 is arranged on the optical axis part of the plug bolt 10 and is axially positioned by a limit ring, and the incident height of the laser can be adjusted by modifying the position of the limit ring, and a pair of screws 13 are arranged in the mounting hole of the vertical bearing seat 9 and are connected to the light source device, thereby constraining the angle and distance of the light source device relative to the flexible grating and providing reliable fixation.

[0036] The adapter plate 7 is used as a flat plate for connecting the hollow rotating table and the optical platform to realize coaxial arrangement with the rotating device. The long strip mounting grooves on both sides are used for fixing with the optical platform, and the threaded holes are used for fixing with the hollow rotating table. The center position is the rotation axis of the whole structure, and a threaded hole is provided for fixing a bolt, and is coaxial with the midpoint of the stretched flexible grating surface.

[0037] The hollow rotating table 8 is a single-degree-of-freedom rotating platform that can accurately read angles, and its central rotating axis is hollow. Its angle reading reflects the receiving angle of the receiving device. In addition, the hollow rotating table is equipped with a tightening knob to fix the rotating table at a specific angle.

[0038] The vertical bearing seat 9, as an adapter for providing the rotational freedom of the laser, is arranged on the optical axis part of the plug bolt and is axially positioned by a limit ring. Modifying the position of the limit ring can adjust the incident height of the laser. Two screws are fixed to the mounting hole of the bearing seat. The screws constrain the angle and distance of the light source device described later relative to the flexible grating, and provide reliable fixation.

[0039] like Figure 7 As shown, each fixing frame is composed of a group of long and short aluminum profiles. The short aluminum profiles 11b and 12b are directly fixed to the hollow turntable by bolts, and the long aluminum profiles 11a and 12a are fixed to the short aluminum profiles by bolts and serve as guide rails for the receiving device. The aluminum profiles will rotate around the central axis following the hollow turntable.

[0040] like Figure 1 and Figure 8 As shown, the light source device d includes: a laser 19, an adapter block 17 and an arc scale 15, wherein: the laser 19 is connected to the adapter block 17 by bolts and hand nuts, and its height and angle can be adjusted manually, the adapter block 17 is set on the screw 13 of the rotating device c, and the arc scale 15 is fixed on the optical platform 1.

[0041] The adapter block is provided with three threaded holes. The threaded holes on both sides are used to fix height adjustment bolts and are locked by nuts to provide support for the laser adapter block. The middle threaded hole is used to fix the support bolts on which the laser is installed.

[0042] In order to accurately measure and install after the overall assembly, a pointer 16 is installed on the screw rod 13 through a clamping block 14, and the pointer vertically points to the scale on the ruler 15 for measuring and controlling the incident angle.

[0043] like Figure 1 and Fig. 9 As shown, the receiving device e comprises: a distance adjustment block 21 and a rotating table 22, a bracket and a light receiving device arranged thereon in sequence, wherein: the distance adjustment block 21 is arranged on the fixed frames 11 and 12, and the movement of the fixed frames can enable the entire receiving device to have a fixed and adjustable light receiving position, and the rotating table 22 provides a controllable and stable rotational degree of freedom, and different light receiving devices can be connected thereto through the bracket.

[0044] The distance adjustment block 21 is used as a device for adjusting the distance of the receiving device and fixing it. It is fixed on the long fixing frame by bolts, and its position can be adjusted along the fixing frame direction to change the distance between the receiving device and the flexible grating, and a rotating table can be fixed on it.

[0045] The rotating platform 22 is a rotating component that provides the optical receiving device with a degree of rotational freedom. Its bottom is fixed to the distance adjustment block by bolts, and its upper surface is provided with an array of threaded holes, and a rotating bracket is fixed by bolts to connect the upper receiving device, providing it with a degree of rotational freedom for readable indication.

[0046] The bracket is used as a transfer piece between the rotating platform and the light receiving device. The rotating platform is fixed at the lower layer, and the dovetail linear guide rail or camera is fixed at the upper layer. Different rotating brackets can be designed according to the needs of different light receiving devices in the experiment to provide transfer for the light receiving device.

[0047] The dovetail linear guide rail is used as a moving part to provide the camera or light screen with translational freedom. The lower part is fixed to the rotating bracket by bolts, so that the guide rail can rotate with the rotating table. Multiple sliders can be installed on the guide rail, and the slider can be moved on the guide rail by turning the knob on one side of the slider.

[0048] When the optical receiving device is a light screen, a dovetail linear guide rail and a corresponding slider are fixed above the bracket, and bolts are fixed on the slider at a certain height through a flange and an adapter. The light screen is connected by first fixing it to an acrylic plate and then fixing it to the bolts. In this design, the position of the light screen can be additionally adjusted in the direction of the guide rail, and the axis of the rotating table can be made to coincide with the plane of the light screen through a fine-tuning structure.

[0049] When the light receiving device is a camera, a camera bracket is designed on a single slider to fix the camera. In this case, the camera can take photos at different positions of the guide rail to synthesize more accurate diffraction fringes. The design of the receiving device realizes a controllable spatial position of the light screen and can easily determine the position of the 0th order diffraction fringes.

[0050] This embodiment relates to a method for testing the diffraction performance of a reflective grating of the above-mentioned device, by fixing a flexible grating on a stretching table through a sample fixture, adjusting the stretching table so that it has suitable grating parameters, and then adjusting the incident angle of the laser by reading the pointer on the scale, adjusting the receiving angle of the receiving device by reading the angle of the hollow rotating table, and then manually adjusting the position of the receiving device from the grating and fixing it. Turn on the laser, fine-tune the position of the laser spot so that the spot is irradiated on the center of the grating, and its diffraction fringes are received by the light receiving device. The experimenter can rotate the laser and the light receiving device around the central axis, or move the light receiving device radially or tangentially, or rotate the light receiving device to change its orientation, or stretch the grating to change the grating parameters, so as to perform multi-degree-of-freedom dynamic measurement of the diffraction performance of the grating.

[0051] After a specific actual experiment, a grating with an initial grating constant of 25μm was fixed on a stretching device and stretched to a grating constant of 31μm. When the incident device emitted a laser with a wavelength of 520nm and incident on the grating at an angle of 20°, the receiving device light screen could capture a total of 26 clear diffraction fringes at a receiving angle of 20°, testing the diffraction effect of the reflective grating. If the receiving device is changed to a camera, the photos can be exported and processed to further obtain the relative light intensity of each fringe.

[0052] Compared with the existing technology, the device can achieve controllable self-centering stretching of the reflection grating sample, freely rotate and precisely control the angle and distance between the incident light and the receiving device, and tune with multiple degrees of freedom to ensure the consistency of the incident point during the experiment. The experimental results are easy to measure, and diffraction fringes within the diffraction angle range of more than 90 degrees can be detected.

[0053] The above-mentioned specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principle and purpose of the present invention. The protection scope of the present invention shall be based on the claims and shall not be limited by the above-mentioned specific implementation. Each implementation scheme within its scope shall be subject to the constraints of the present invention.

Claims

1. A coaxial self-centering tunable reflection grating diffraction performance test device, characterized in that: include: A supporting device, a stretching device for stretching a flexible grating sample, a rotating device for coaxially changing and measuring the incident and output angles, a light source device for fixing and adjusting the incident laser, and a receiving device for fixing and adjusting the position and orientation of a receiving screen or a camera, wherein: the rotating device is respectively connected to the light source device and the receiving device, and the stretching device is fixedly arranged on the supporting device, and self-centering is achieved by adjusting the relative position.

2. The coaxial self-centering tunable reflection grating diffraction performance testing device according to claim 1 is characterized in that: The stretching device comprises: a sample clamp and a stretching platform, wherein: the sample clamp is fixed on the stretching platform through a stopper or a thread, and the stretching platform is arranged on the supporting device.

3. The coaxial self-centering tunable reflection grating diffraction performance testing device according to claim 1 is characterized in that: The supporting device includes: a triangular bracket, a vertical adapter plate and a vertical pad, wherein: two triangular brackets are arranged opposite to each other, the vertical adapter plate is fixedly connected to the triangular bracket by threads, and the through grooves on the vertical pad enable the stretching table to be fixed on the vertical adapter plate at different heights and horizontal positions, thereby reaching the same height as the light source, while avoiding misalignment caused by processing errors.

4. The coaxial self-centering tunable reflection grating diffraction performance testing device according to claim 1 is characterized in that: The rotating device includes: an adapter plate, a hollow rotating table, a plug bolt, a fixing frame, a bearing screw mechanism and an arc scale, wherein: the hollow rotating table is fixed to the optical platform through the adapter plate, the plug bolt is connected to the adapter plate through a thread and is coaxially arranged with the hollow rotating table, two fixing frames are fixedly arranged on the rotating part of the hollow rotating table to constrain the angle and distance of the receiving device relative to the flexible grating while providing reliable fixation, the vertical bearing seat of the bearing screw mechanism is arranged on the optical axis position of the plug bolt and axially positioned by a limit ring, and the incident height of the laser can be adjusted by modifying the position of the limit ring, a pair of screws of the bearing screw mechanism are arranged in the mounting hole of the vertical bearing seat and are connected to the light source device, thereby constraining the angle and distance of the light source device relative to the flexible grating and providing reliable fixation, and the arc scale is fixed on the optical platform for reading the laser incident angle.

5. The coaxial self-centering tunable reflection grating diffraction performance testing device according to claim 1 is characterized in that: The light source device comprises: a laser, an adapter block and a height adjustment bolt, wherein: the laser is connected to the adapter block through a bolt and a hand-tightened nut, and its height and angle can be manually adjusted through the height adjustment bolt; the adapter block is passed through by a lead screw and is locked by a double nut, so that the distance between the light source and the sample can be adjusted.

6. The coaxial self-centering tunable reflection grating diffraction performance testing device according to claim 1 is characterized in that: The receiving device includes: a distance adjustment block and a rotating table, a rotating bracket, a dovetail groove linear guide and a light receiving device arranged thereon in sequence, wherein: the distance adjustment block is fixed to the fixed bracket by bolts and is directly opposite to the sample to be tested, and the distance adjustment of the light receiving device relative to the flexible grating is achieved by sliding on the fixed bracket. The rotating table is used to accurately adjust the orientation angle of the light receiving device, and the dovetail groove linear guide is fixed on the rotating table by the rotating bracket to horizontally adjust the light receiving device.

7. The coaxial self-centering tunable reflection grating diffraction performance testing device according to claim 1 is characterized in that: The light receiving device is implemented as a camera or a light screen. When a camera is used, the detection of diffraction fringes on a flat light screen is achieved by shooting and synthesizing by translation, or the detection of diffraction fringes on a circular arc light screen is achieved by shooting and synthesizing by rotating around a central axis. When a light screen is used, direct observation of the diffraction fringes on the flat light screen is achieved through the principle of diffuse reflection.

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