Michelson interferometer measuring device and measuring method thereof

Abstract

A Michelson interferometer measuring device and a measuring method thereof, comprising a base, a test bench and a digital caliper, wherein the test bench is fixed on the upper surface of the base through a supporting column, threaded slots are provided at four top corners of the base, each threaded slot is threadedly connected with a leveling screw, a track mounting slot is provided on the upper surface of the test bench, two parallel tracks are fixed in the track mounting slot along a direction perpendicular to the front side of the test bench, a sliding block is slidably bridged on the two parallel tracks, an M2 plane mirror is fixed on the sliding block, a beam splitter, a compensation mirror and an M1 plane mirror are sequentially arranged at the rear of the test bench, the M1 plane mirror is vertically arranged with the M2 plane mirror, an observation screen is arranged behind the beam splitter through a bracket, a lead screw is rotatably connected in the track mounting slot, the invention converts the movement of the M2 plane mirror into the movement of a rack by arranging a gear on the lead screw, and the movement amount is directly measured by a digital caliper fixed above the rack, the operation is simple, the gear transmission is accurate, and the reading can be completed quickly.

Description

Technical Field

[0001] The invention relates to an interference instrument, and in particular to a Michelson interferometer measuring device and a measuring method thereof. Background Art

[0002] Michelson interferometer is a precision instrument that uses the interference phenomenon of light to measure tiny lengths and their changes. Its measurement accuracy can reach half an optical wavelength. The principle of Michelson interferometer is that a beam of incident light is divided into two beams and each is reflected back by the corresponding plane mirror, so that the two beams of light can interfere. The different optical paths of the two beams of light in interference can be achieved by adjusting the length of the interference arm and changing the refractive index of the medium, so that different interference patterns can be formed. Interference fringes are the trajectories of equal optical path difference points. Therefore, to analyze the pattern produced by a certain interference, the function of the optical path difference position distribution of the coherent light must be calculated. G2 is coated with a semi-transparent and semi-reflective film on one side, G1 is a compensation plate, M1 and M2 are plane reflectors, M1 is fixed, and M2 is connected to a precision wire so that it can move forward and backward. The minimum reading is 10-4mm, which can be estimated to 10-5mm. There are several small screws behind M1 and M2 to adjust their orientation. When M2 and M1' are strictly parallel, M2 will move, showing as circular ring-shaped fringes of equal inclination interference that are constantly "spitting out" from the center or "swallowing in" to the center. When the "air gap" between the two plane mirrors increases, the center will "spit out" fringes one by one; otherwise, it will "swallow in". When M2 and M1' are not strictly parallel, they will show as equal-thickness interference fringes. When M2 moves, the fringes constantly move past a certain marked position in the field of view. The relationship between the M2 translation distance d and the fringes movement number N satisfies: d=Nλ / 2, where λ is the wavelength of the incident light.

[0003] Usually, Michelson interferometers are divided into two types: locked and unlocked. Generally, a locked Michelson interferometer can ensure the correspondence between the handwheel and the micro-motion drum, but the operation is complicated and difficult to master, and the experiment often fails due to improper operation. In an unlocked Michelson interferometer, the handwheel and the micro-motion drum frame are driven by friction. Every time the handwheel is coarsely adjusted, the micro-motion drum does not move, and there is no correspondence between the two, resulting in misalignment, which makes it impossible to read the data. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a Michelson interferometer measuring device and a measuring method thereof which have low measuring difficulty and are convenient to operate.

[0005] The technical solution adopted by the present invention is:

[0006] A Michelson interferometer measuring device comprises a base, a test bench and a digital caliper. The test bench is fixed on the upper surface of the base through a supporting column. Threaded slots are provided at four top corners of the lower surface of the base. A leveling screw is threadedly connected in each threaded slot. A track mounting groove is provided on the upper surface of the test bench. Two parallel tracks are fixed in the track mounting groove along a direction perpendicular to the front side of the test bench. A sliding block is slidably connected across the two parallel tracks. An M2 plane mirror is fixed on the sliding block. A beam splitter, a compensating mirror and an M1 plane mirror are sequentially arranged at the rear of the test bench. The M1 plane mirror is arranged vertically to the M2 plane mirror. The rear of the beam splitter An observation screen is set through the bracket, a lead screw is rotatably connected between the side walls connected at both ends of the two parallel tracks in the track mounting groove, and one end of the lead screw passes through the side wall of the track mounting groove and passes through the front side wall of the test bench, and is connected with a gear and an adjusting handwheel in sequence at the end, a nut is sleeved on the lead screw in the track mounting groove, and the top of the nut is fixedly connected to the bottom of the sliding block, a rack mounting plate is fixed below the gear on the front side wall of the test bench, a rack sliding groove is opened on the rack mounting plate, a rack is slidably connected in the rack sliding groove, the rack is meshed with the teeth of the gear at the bottom, and a digital caliper for measuring the movement distance of the rack is fixed on the front side wall of the test bench.

[0007] An anti-skid rubber pad is fixed to the bottom of the leveling screw.

[0008] A caliper fixing plate is fixed above the rack mounting plate on the front side wall of the test bench, and a digital caliper with a measuring head facing downward is fixed on the caliper fixing plate.

[0009] The movable measuring head of the digital caliper is closely connected with the right end of the rack.

[0010] The diameter of the gear is larger than the diameter of the adjusting hand wheel, the pitch of the gear is twice the pitch of the lead screw, the moving distance of the rack is twice the moving distance of the sliding block, and the lead screw is a high-precision ball screw with a zero gap and a lead of 2mm.

[0011] One surface of the beam splitter is plated with a semi-reflective metal film.

[0012] The compensation mirror comprises a compensation mirror A and a compensation mirror B, and the compensation mirror A and the compensation mirror B are fixed on the test bench through a positioning shaft.

[0013] The compensation mirror A and the compensation mirror B are arranged at an angle of 90°, and the compensation mirror A and the compensation mirror B are arranged at an angle of 45° to the M2 plane mirror.

[0014] A Michelson interferometer measurement method, the steps of which are:

[0015] a. A monochromatic light source illuminates the beam splitter, and the adjusting hand wheel is turned to rotate the lead screw, which drives the sliding block connected to the track to move, so that the M2 plane mirror on the sliding block is displaced under the action of the lead screw until interference fringes are adjusted. When the lead screw rotates, the gear also rotates, and the rack meshing with the gear is displaced. The displacement is directly measured by the digital caliper as S1;

[0016] b. Calculate the moving distance of the M2 plane mirror. The number of teeth on the gear is n, and the moving distance of the M2 plane mirror is S=S1 / 2.

[0017] Beneficial effects of the present invention: The present invention converts the movement of the M2 plane mirror into the movement of the rack by arranging a gear on the lead screw, and the movement amount is directly measured by a digital caliper fixed above the rack. The operation is simple, the gear transmission is accurate, and the reading can be completed quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a top view of the structure of the present invention.

[0019] Figure 2 It is the structural front view of the present invention.

[0020] Among them: 1-test bench; 2-beam splitter; 3-observation screen; 4-compensation mirror A; 5-positioning axis; 6-compensation mirror B; 7-M1 plane mirror; 8-track mounting groove; 9-screw; 10-sliding block; 11-M2 plane mirror; 12-track; 13-rack mounting plate; 14-rack slide groove; 15-rack; 16-adjusting handwheel; 17-gear; 18-movable measuring head; 19-digital caliper; 20-caliper fixing plate; 21-base; 22-leveling screw; 23-support column. DETAILED DESCRIPTION

[0021] The present invention will be described in detail below with reference to specific embodiments.

[0022] A Michelson interferometer measuring device, comprising a base 21, a test bench 1 and a digital caliper 19, wherein the test bench 1 is fixed on the upper surface of the base 21 through a support column 23, threaded slots are provided at four vertex corners of the lower surface of the base 21, and a leveling screw 22 is threadedly connected in each threaded slot, a track mounting groove 8 is provided on the upper surface of the test bench 1, two parallel tracks 12 are fixed in the track mounting groove 8 along a direction perpendicular to the front side wall of the test bench 1, a sliding block 10 is slidably bridged on the two parallel tracks 12, and an M2 plane mirror 11 is fixed on the sliding block 10, a beam splitter 2, a compensation mirror and an M1 plane mirror 7 are sequentially arranged at the rear of the test bench 1, the M1 plane mirror 7 is arranged perpendicular to the M2 plane mirror 11, and the rear of the beam splitter 2 An observation screen 3 is arranged through a bracket, a lead screw 9 is rotatably connected between the side walls connected at both ends of two parallel tracks in the track mounting groove 8, and one end of the lead screw 9 passes through the side wall of the track mounting groove 8, and passes through the front side wall of the test bench 1, and is connected with a gear 17 and an adjusting hand wheel 16 in sequence at the end, a nut is sleeved on the lead screw 9 in the track mounting groove 8, and the top of the nut is fixedly connected to the bottom of the sliding block 10, a rack mounting plate 13 is fixed below the gear 17 on the front side wall of the test bench 1, a rack slide groove 14 is opened on the rack mounting plate 13, a rack 15 is slidably connected in the rack slide groove 14, the rack 15 is meshed with the teeth of the gear 17 at the bottom, and a digital caliper 19 for measuring the movement distance of the rack 15 is fixed on the front side wall of the test bench 1.

[0023] An anti-skid rubber pad is fixed to the bottom of the leveling screw 22.

[0024] A caliper fixing plate 20 is fixed above the rack mounting plate 13 on the front side wall of the test bench 1, and a digital caliper 19 with a measuring head facing downward is fixed on the caliper fixing plate 20.

[0025] The movable measuring head 18 of the digital caliper 19 is closely connected to the right end of the rack 15 .

[0026] The diameter of the gear 17 is larger than the diameter of the adjusting hand wheel 16, the pitch of the gear 17 is twice the pitch of the screw 9, the moving distance of the rack 15 is twice the moving distance of the sliding block 10, and the screw 9 is a high-precision ball screw with a zero clearance and a lead of 2 mm.

[0027] One surface of the beam splitter 2 is coated with a semi-reflective metal film.

[0028] The compensation mirrors include compensation mirror A4 and compensation mirror B6, and compensation mirror A4 and compensation mirror B6 are fixed on the test bench 1 through a positioning shaft 5.

[0029] The compensation mirror A4 and the compensation mirror B6 are arranged at an angle of 90°, and the compensation mirror A4 and the compensation mirror B6 are arranged at an angle of 45° to the M2 plane mirror 11.

[0030] Working principle: When the lead screw 9 rotates one circle, the moving block 10 moves 2 mm. The gear 17 on the lead screw 9 is coaxial with the lead screw 9. When the lead screw 9 rotates one circle, the gear 17 will also rotate one circle. The pitch of the gear 17 is twice the pitch of the lead screw 9. After the lead screw 9 rotates one circle, the moving distance of the rack 15 is the pitch × the number of teeth, that is, 2 × pitch × the number of teeth. Therefore, the moving distance of the moving block 10 is 1 / 2 of the moving distance of the rack 15 × the number of teeth.

[0031] A Michelson interferometer measurement method, the steps of which are:

[0032] a. A monochromatic light source illuminates the beam splitter 2, and the adjusting hand wheel 16 is turned to rotate the lead screw 9, which drives the sliding block 10 connected to the track 12 to move, so that the M2 plane mirror 11 on the sliding block 10 is displaced under the action of the lead screw 9 until interference fringes are adjusted. When the lead screw 9 rotates, the gear 17 also rotates, and the rack 15 meshing with the gear 17 is displaced. The displacement is directly measured by the digital caliper 19 as S1;

[0033] b. Calculate the moving distance of the M2 plane mirror 11. The number of teeth on the gear is n, and the moving distance of the M2 plane mirror 11 is S=S1 / 2n. Example

[0034] A Michelson interferometer measuring device, comprising a base 21, a test bench 1 and a digital caliper 19, wherein the test bench 1 is fixed on the upper surface of the base 21 through a support column 23, threaded slots are provided at four vertex corners of the lower surface of the base 21, and each threaded slot is threadedly connected with a leveling screw 22, a track mounting groove 8 is provided on the upper surface of the test bench 1, two parallel tracks 12 are fixed in the track mounting groove 8 along a direction perpendicular to the front side wall of the test bench 1, a sliding block 10 is slidably connected across the two parallel tracks 12, and an M2 plane mirror 11 is fixed on the sliding block 10, and the test bench 10 is provided with a plurality of screw holes, wherein the screw holes are provided with screw holes, and ... The rear part of the test bench 1 is provided with a beam splitter 2, a compensation mirror and an M1 plane mirror 7 in sequence. The M1 plane mirror 7 is vertically arranged with the M2 plane mirror 11. An observation screen 3 is arranged behind the beam splitter 2 through a bracket. A lead screw 9 is rotatably connected between the side walls connected at both ends of the two parallel tracks in the track installation groove 8, and one end of the lead screw 9 passes through the side wall of the track installation groove 8 and passes through the front side wall of the test bench 1. A gear 17 and an adjusting hand wheel 16 are connected in sequence at the end. A nut is sleeved on the lead screw 9 in the track installation groove 8, and the top of the nut is fixedly connected to the bottom of the sliding block 10. A rack mounting plate 13 is fixed below the gear 17, and a rack slide groove 14 is provided on the rack mounting plate 13. A rack 15 is slidably connected in the rack slide groove 14. The rack 15 is meshed with the teeth of the gear 17 at the bottom. A digital caliper 19 for measuring the movement distance of the rack 15 is fixed on the front side wall of the test bench 1. The diameter of the gear 17 is larger than the diameter of the adjusting hand wheel 16. The pitch of the gear 17 is twice the pitch of the screw 9. The moving distance of the rack 15 is twice the moving distance of the sliding block 10. The screw 9 is a high-precision ball screw with a zero clearance and a lead of 2mm. When measuring, first illuminate the beam splitter 2 with a monochromatic light source, turn the adjusting hand wheel 16 to rotate the lead screw 9, and drive the sliding block 10 connected to the track 12 to move, so that the M2 plane mirror 11 on the sliding block 10 is displaced under the action of the lead screw 9 until interference fringes are adjusted. When the lead screw 9 rotates, the gear 17 also rotates, and the rack 15 meshing with the gear 17 is displaced. The digital caliper 19 directly measures the displacement S1, and calculates the moving distance of the M2 plane mirror 11. The number of teeth of the gear is 40, and the moving distance of the M2 plane mirror 11 is S=S1 / 2×40.

[0035] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A Michelson interferometer measuring device, characterized in that: The invention comprises a base (21), a test bench (1) and a digital caliper (19), wherein the test bench (1) is fixed on the upper surface of the base (21) by a support column (23), threaded slots are provided at four top corners of the lower surface of the base (21), and each threaded slot is threadedly connected with a leveling screw (22), and a track mounting slot (8) is provided on the upper surface of the test bench (1), and two parallel tracks (12) are fixed in the track mounting slot (8) in a direction perpendicular to the front side wall of the test bench (1), and a sliding block (10) is slidably bridged on the two parallel tracks (12), and an M2 plane mirror (11) is fixed on the sliding block (10), and a beam splitter (2), a compensation mirror and an M1 plane mirror (7) are sequentially arranged at the rear of the test bench (1), and the M1 plane mirror (7) is arranged vertically to the M2 plane mirror (11), and an observation screen is arranged behind the beam splitter (2) through a bracket. (3), a lead screw (9) is rotatably connected between the side walls connected at both ends of the two parallel tracks (12) in the track mounting groove (8), and one end of the lead screw (9) passes through the side wall of the track mounting groove (8) and passes through the front side wall of the test bench (1), and is connected to a gear (17) and an adjusting hand wheel (16) in sequence at the end, a nut is sleeved on the lead screw (9) in the track mounting groove (8), and the top of the nut is fixedly connected to the bottom of the sliding block (10), a rack mounting plate (13) is fixed below the gear (17) on the front side wall of the test bench (1), a rack slide groove (14) is opened on the rack mounting plate (13), a rack (15) is slidably connected in the rack slide groove (14), and the rack (15) is meshed with the teeth of the gear (17) at the bottom, and a digital caliper (19) for measuring the movement distance of the rack (15) is fixed on the front side wall of the test bench (1); A caliper fixing plate (20) is fixed above the rack mounting plate (13) on the front side wall of the test bench (1), and a digital caliper (19) with a measuring head facing downward is fixed on the caliper fixing plate (20), and a movable measuring head (18) of the digital caliper (19) is fitted and connected to the right end of the rack (15), the diameter of the gear (17) is larger than the diameter of the adjusting hand wheel (16), the pitch of the gear (17) is twice the pitch of the lead screw (9), the moving distance of the rack (15) is twice the moving distance of the sliding block (10), and the lead screw (9) is a high-precision ball screw with a zero clearance and a lead of 2 mm; The compensating mirror comprises a compensating mirror A (4) and a compensating mirror B (6), wherein the compensating mirror A (4) and the compensating mirror B (6) are fixed on the test bench (1) via a positioning shaft (5); the compensating mirror A (4) and the compensating mirror B (6) are arranged at an angle of 90°, and the compensating mirror A (4) and the compensating mirror B (6) are arranged at an angle of 45° to the M2 plane mirror (11); The measurement steps of the device are as follows: a. A monochromatic light source is irradiated on the beam splitter (2), and the adjusting hand wheel (16) is turned to rotate the lead screw (9), thereby driving the sliding block (10) connected to the track (12) to move, so that the M2 plane mirror (11) on the sliding block (10) is displaced under the action of the lead screw (9) until interference fringes are adjusted. When the lead screw (9) rotates, the gear (17) also rotates, and the rack (15) meshing with the gear (17) is displaced. The displacement is directly measured by the digital caliper (19) as S1; b. Calculate the moving distance of the M2 plane mirror (11). The number of teeth on the gear is n, and the moving distance of the M2 plane mirror (11) is S = S1 / 2n.

2. The Michelson interferometer measuring device according to claim 1, characterized in that: An anti-slip rubber pad is fixed to the bottom of the leveling screw (22).

3. The Michelson interferometer measuring device according to claim 1, characterized in that: One surface of the beam splitter (2) is coated with a semi-reflective metal film.

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