A surface shape measurement device based on a microchip solid-state laser frequency shift feedback displacement sensor

Abstract

This invention discloses a surface shape measurement device based on orthogonal polarized laser displacement sensors. The device comprises a first orthogonal polarized laser displacement sensor, a second orthogonal polarized laser displacement sensor, a two-dimensional scanner, and a controller. Both the first and second orthogonal polarized laser displacement sensors are mounted on the two-dimensional scanner. The scanner drives the first and second orthogonal polarized laser displacement sensors to move along a predetermined trajectory. The controller is connected to the first, second, and two-dimensional scanners. The surface shape parameters of the sample are obtained based on the distance between the reference sample and the sample to be measured at each sampling point. This device is low-cost, can measure free-form surfaces, and enables in-situ measurement of samples.

Description

Technical Field

[0001] This invention belongs to the technical field of surface shape measurement devices, and particularly relates to a surface shape measurement device based on a microchip solid-state laser frequency shift feedback displacement sensor. Background Technology

[0002] Surface shape measurement devices have significant applications, and the optical path structure of common surface shape measurement devices is as follows: Figure 1 As shown, it mainly utilizes the principle and structure of the Fizeau interferometer. In operation, the laser emitted from the laser beam passes through a converging lens, beam splitter, and collimating lens to form a parallel beam. When the parallel beam passes through a transmission standard mirror, part of the light is reflected by the rear surface of the transmission standard mirror to form a reference beam, while the other part passes through the transmission standard mirror to reach the surface of the sample under test. After being reflected by the sample, it forms a measurement beam. The reference beam and the measurement beam return along the original optical path, and after reflection by the rear surface of the beam splitter, interference fringes are formed at the detector. By analyzing the interference fringes, the surface shape of the sample under test can be calculated. However, measuring the surface shape data of large-diameter samples (diagonal dimension greater than 500 mm) using existing surface shape measurement devices is extremely expensive. Summary of the Invention

[0003] The purpose of this invention is to solve the problems in the background art and to propose a surface shape measurement device based on a microchip solid-state laser frequency shift feedback displacement sensor.

[0004] To achieve the above objectives, this invention proposes a surface shape measurement device based on a microchip solid-state laser frequency shift feedback displacement sensor, comprising:

[0005] The first microchip solid-state laser frequency shift feedback displacement sensor is mounted on a two-dimensional scanner and emits a laser towards a reference sample. The initial distance A between the first microchip solid-state laser frequency shift feedback displacement sensor and the surface of the reference sample is measured.

[0006] The second micro-chip solid-state laser frequency shift feedback displacement sensor is mounted on a two-dimensional scanner. The second micro-chip solid-state laser frequency shift feedback displacement sensor emits laser light onto the surface of the sample to be tested, and the initial distance B between the second micro-chip solid-state laser frequency shift feedback displacement sensor and the sample to be tested is measured.

[0007] A two-dimensional scanner drives a first micro-chip solid-state laser frequency shift feedback displacement sensor and a second micro-chip solid-state laser frequency shift feedback displacement sensor to move along a predetermined trajectory. The scanner scans the laser's movement trajectory on corresponding reference and test samples, and measures the change in distance Δ between the first micro-chip solid-state laser frequency shift feedback displacement sensor and the surface of the reference sample at each sampling point along the movement trajectory. nnThe change in distance ξ between the second microchip solid-state laser frequency shift feedback displacement sensor and the sample under test nn ;

[0008] The controller is connected to a first microchip solid-state laser frequency shift feedback displacement sensor, a second microchip solid-state laser frequency shift feedback displacement sensor, and a two-dimensional scanner to obtain initial distance A, initial distance B, and distance change Δ. nn ξ, distance change nn And based on the initial distance A, initial distance B, and distance change Δ nn ξ, distance change nn Calculate the actual distance A1 between the first micro-chip solid-state laser frequency shift feedback displacement sensor and the surface of the reference sample, and the actual distance B1 between the second micro-chip solid-state laser frequency shift feedback displacement sensor and the surface of the sample to be tested at each sampling point on the moving trajectory. Then, calculate the distance C between the reference sample and the sample to be tested based on the actual distances A1 and B1 at each sampling point, and finally obtain the surface shape parameters of the sample to be tested.

[0009] Preferably, the predetermined trajectory is shape.

[0010] Preferably, the distance change Δ at each sampling point location nn Recorded as Where the first n represents the number of rows and the second n represents the number of columns.

[0011] Preferably, the actual distance A1 at each sampling point location is based on the distance change Δ nn The result is obtained by summing the initial distance A, and is denoted as .

[0012] Preferably, the distance change ξ at each sampling point location nn Recorded as Where the first n represents the number of rows and the second n represents the number of columns.

[0013] Preferably, the actual distance B1 at each sampling point location is determined according to the distance variation ξ. nm The result is obtained by summing the initial distance B, denoted as

[0014] Preferably, the distance C at each sampling point is obtained by summing the actual distance A1 and the actual distance B1, and is denoted as...

[0015] Preferably, the surface shape measuring device further includes a collimating lens and a focusing lens, wherein the collimating lens is located between the reference sample and the focusing lens, and both the collimating lens and the focusing lens are located on the path of the laser irradiated from the first microchip solid-state laser frequency shift feedback displacement sensor to the reference sample;

[0016] The beneficial effects of the present invention are: the present invention can measure free-form surfaces, the device has low manufacturing cost, and it can realize in-situ measurement of samples.

[0017] The features and advantages of the present invention will be described in detail through embodiments and in conjunction with the accompanying drawings. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the optical path structure of the existing surface shape measuring device of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of Embodiment 1 of the present invention.

[0020] Figure 3 This is a schematic diagram of the predetermined trajectory of a two-dimensional scanner according to an embodiment of the present invention.

[0021] Figure 4 This is a schematic diagram of the predetermined trajectory in Embodiment 2 of the present invention.

[0022] In the figure: 1-Reference sample, 2-Collimating lens, 3-Focusing lens, 4-Two-dimensional scanner, 5-First microchip solid-state laser frequency shift feedback displacement sensor, 6-Second microchip solid-state laser frequency shift feedback displacement sensor, 7-Sample to be tested. Detailed Implementation

[0023] See Example 1 Figure 2 This embodiment provides a surface shape measurement device based on a microchip solid-state laser frequency shift feedback displacement sensor, comprising:

[0024] The first micro-chip solid-state laser frequency shift feedback displacement sensor 5 is mounted on the two-dimensional scanner 4, emits laser to the reference sample 1, and measures the initial distance A between the first micro-chip solid-state laser frequency shift feedback displacement sensor 5 and the surface of the reference sample 1.

[0025] The second micro-chip solid-state laser frequency shift feedback displacement sensor 6 is mounted on the two-dimensional scanner 4. The second micro-chip solid-state laser frequency shift feedback displacement sensor 6 emits laser light to the surface of the sample 7 to be tested, and measures the initial distance B between the second micro-chip solid-state laser frequency shift feedback displacement sensor 6 and the sample 7 to be tested.

[0026] Two-dimensional scanner 4 drives a first micro-chip solid-state laser frequency shift feedback displacement sensor 5 and a second micro-chip solid-state laser frequency shift feedback displacement sensor 6 to move along a predetermined trajectory, scanning the movement trajectory of the laser on the corresponding reference sample 1 and the sample to be tested 7, and measuring the change in distance Δ between the first micro-chip solid-state laser frequency shift feedback displacement sensor 5 and the surface of the reference sample 1 at each sampling point on the movement trajectory.nn The change in distance ξ between the second microchip solid-state laser frequency shift feedback displacement sensor 6 and the sample 7 under test nn ;

[0027] The controller is connected to the first microchip solid-state laser frequency shift feedback displacement sensor 5, the second microchip solid-state laser frequency shift feedback displacement sensor 6, and the 2D scanner 4 to obtain the initial distance A, the initial distance B, and the distance change Δ. nn ξ, distance change nn And based on the initial distance A, initial distance B, and distance change Δ nn ξ, distance change nn Calculate the actual distance A1 between the first micro-chip solid-state laser frequency shift feedback displacement sensor 5 and the surface of the reference sample 1, and the actual distance B1 between the second micro-chip solid-state laser frequency shift feedback displacement sensor 6 and the surface of the sample to be tested 7 at each sampling point on the moving trajectory. Then, calculate the distance C between the reference sample and the sample to be tested based on the actual distances A1 and B1 at each sampling point. Finally, the surface shape parameters of the sample to be tested 7 can be obtained based on the distance C between the reference sample 1 and the sample to be tested 7 at each sampling point.

[0028] The first microchip solid-state laser frequency shift feedback displacement sensor 5 and the second microchip solid-state laser frequency shift feedback displacement sensor 6 have the function of measuring relative displacement. The sample to be tested 7 is fixedly clamped on the mounting stage, which is located to the right of the two-dimensional scanner 4. The two-dimensional scanner 4 is an existing structure and will not be described in detail in this application. The sample to be tested 7 is a large-diameter sample with a surface shape whose diagonal dimension is greater than 500 mm.

[0029] like Figure 3 As shown, the predetermined trajectory is Shape; the small black dots in the image represent sampling points; the arrows in the image indicate the direction of movement.

[0030] The change in distance Δ between the first micro-chip solid-state laser frequency shift feedback displacement sensor 5 and the surface of the reference sample 1 at each sampling point location. nn Recorded as Where the first n represents the number of rows and the second n represents the number of columns.

[0031] The actual distance A1 between the first micro-chip solid-state laser frequency shift feedback displacement sensor 5 and the surface of the reference sample 1 at each sampling point is based on the distance change Δ nn The result is obtained by summing the initial distance A, and is denoted as .

[0032] The change in distance ξ between the second micro-chip solid-state laser frequency shift feedback displacement sensor 6 and the sample 7 at each sampling point location. nn Recorded as Where the first n represents the number of rows and the second n represents the number of columns.

[0033] The actual distance B1 between the second micro-chip solid-state laser frequency shift feedback displacement sensor 6 and the surface of the sample 7 at each sampling point is determined by the distance change ξ. nm The result is obtained by summing the initial distance B, denoted as

[0034] The distance C between the reference sample 1 and the sample to be tested 7 at each sampling point is obtained by summing the actual distances A1 and B1 mentioned above, and is denoted as...

[0035]

[0036] See Example 2 Figure 4 This embodiment provides a surface shape measurement device based on a microchip solid-state laser frequency shift feedback displacement sensor. The surface shape measurement device also includes a collimating lens 2 and a focusing lens 3. The collimating lens 2 is located between the reference sample 1 and the focusing lens 3. Both the collimating lens 2 and the focusing lens 3 are located on the path of the laser irradiated from the first microchip solid-state laser frequency shift feedback displacement sensor 5 to the reference sample 1. The rest of the structure is the same as in embodiment 1.

[0037] The above embodiments are illustrative of the present invention and are not intended to limit the present invention. Any simple modifications to the present invention are within the scope of protection of the present invention.

Claims

1. A surface shape measuring device based on a microchip solid laser frequency-shifted feedback displacement sensor, characterized by, Comprise: The first microchip solid laser frequency shift feedback displacement sensor is installed on a two-dimensional scanner, emits laser to a reference sample, and measures the initial distance A between the first microchip solid laser frequency shift feedback displacement sensor and the surface of the reference sample; The second microchip solid laser frequency shift feedback displacement sensor is installed on a two-dimensional scanner, emits laser to the surface of the sample to be measured, and measures the initial distance B between the second microchip solid laser frequency shift feedback displacement sensor and the sample to be measured; A two-dimensional scanner drives the first microchip solid laser frequency-shift feedback displacement sensor and the second microchip solid laser frequency-shift feedback displacement sensor to move along a predetermined track, scans the moving track of the laser on the corresponding reference sample and the sample to be measured, and measures the distance change amount Δ of the first microchip solid laser frequency-shift feedback displacement sensor from the surface of the reference sample at each sampling point position on the moving track nn , the distance change amount ξ between the second microchip solid laser frequency-shift feedback displacement sensor and the sample to be measured nn ; A controller connected with the first microchip solid laser frequency-shift feedback displacement sensor, the second microchip solid laser frequency-shift feedback displacement sensor and the two-dimensional scanner to obtain initial distance A, initial distance B, distance variation Δ nn , distance variation ξ nn , and calculate actual distance A1 of the first microchip solid laser frequency-shift feedback displacement sensor to the surface of the reference sample, actual distance B1 of the second microchip solid laser frequency-shift feedback displacement sensor to the surface of the sample to be measured at each sampling point position on the moving track according to initial distance A, initial distance B, distance variation Δ nn , distance variation ξ nn , and calculate distance C of the reference sample and the sample to be measured according to the corresponding actual distance A1 and actual distance B1 at each sampling point position, and finally obtain the surface shape parameter of the sample to be measured.

2. The apparatus for measuring surface profile based on microchip solid-state laser frequency-shifted feedback displacement sensor according to claim 1, wherein: The predetermined trajectory is in the shape of a circle.

3. The apparatus for measuring surface profile based on microchip solid-state laser frequency-shifted feedback displacement sensor according to claim 1, wherein: The distance variation Δ at each sampling point position nn denoted by where the first n represents the number of rows and the second n represents the number of columns.

4. The apparatus for measuring surface shape based on the microchip solid laser frequency-shifted feedback displacement sensor according to claim 3, wherein: The actual distance A1 at each sampling point position is calculated according to the distance variation Δ nn and the initial distance A, and is denoted as 5. The apparatus for measuring surface shape based on the microchip solid laser frequency-shift feedback displacement sensor according to claim 1 or 4, characterized in that: The distance variation ξ at each sampling point position nn denoted by where the first n represents the number of rows and the second n represents the number of columns.

6. The apparatus for measuring surface shape based on the microchip solid laser frequency-shifted feedback displacement sensor according to claim 5, wherein: The actual distance B1 at each sampling point position varies according to a distance variation ξ nm and the initial distance B, and is calculated by summation, denoted as 7. The microchip solid-state laser frequency-shifted feedback displacement sensor based surface figure measurement apparatus according to claim 6, wherein: The distance C at each sampling point position is summed according to the actual distance A1 and the actual distance B1, and is denoted as 8. The microchip solid-state laser frequency-shifted feedback displacement sensor based surface figure measurement apparatus according to claim 1, wherein: It also comprises a collimating lens and a focusing lens, the collimating lens is between the reference sample and the focusing lens, and the collimating lens and the focusing lens are both located on the path of the laser irradiated by the first microchip solid laser frequency shift feedback displacement sensor to the reference sample.

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