CN113624456A - Multi-wavelength laser interference device - Google Patents
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Abstract
The invention provides a multi-wavelength laser interference device, which is characterized by comprising: the laser generating unit is used for generating a plurality of laser light sources with different wavelengths; the light source conversion unit is used for converting the laser light source into a point light source; the collimating unit is movably arranged on the guide rail mechanism and can move along the length direction of the guide rail mechanism, and is used for enabling the split light beams to form parallel light beams and emit the parallel light beams into the optical system, so that reference light beams and test light beams are formed by reflection; the imaging unit is used for carrying out interference imaging on the filtered reference light beam and the filtered test light beam, wherein the collimating unit and the imaging unit both adopt achromatic structures, different wavelengths at least comprise a visible light wavelength and a near infrared wavelength, and the collimating unit is adjusted to enable the laser light sources of the visible light wavelength and the near infrared wavelength to be confocal.
Description
Technical Field
The invention belongs to the field of optical interference detection, relates to a laser interference device, and particularly relates to a multi-wavelength laser interference device.
Background
The transmitted wavefront is an important performance evaluation index of an optical system, and is therefore very important for detection of the transmitted wavefront. Whereas conventional transmitted wavefront sensing techniques can only sense wavefronts of a particular wavelength. The latest multi-wavelength wavefront detection technology utilizes the change rule of wavefront along with wavelength, only needs to detect the specific wavelength wavefront, and then utilizes the function relation of wavefront and wavelength to predict the wavefront with any wavelength in a certain waveband range, thereby indirectly realizing the detection of multi-wavelength transmission wavefront.
Although multi-wavelength transmitted wavefront detection can be achieved in theory and also verified experimentally. However, the conventional multi-wavelength transmission wavefront detection technology still stays in an experimental verification stage due to the lack of a complete detection instrument. And the multi-wavelength wavefront detection device used in the experiment has the following problems:
1. when the wavefront with different wavelengths is measured, the laser needs to be manually replaced and readjusted, so that the measurement time is greatly prolonged, and the measurement efficiency is low;
2. because the collimation system is a monochromatic system, larger chromatic aberration exists, the focus changes along with the wavelength in the process of multi-wavelength wavefront measurement, and the collimation lens is inconvenient to adjust, the collimation degree of the reference beam is influenced, and the measurement result is further influenced; if the collimating lens is adjusted on the basis of the original experiment, a large optical axis deviation error is caused, and the measuring result is also greatly influenced. Therefore, experiments only prove the feasibility of the multi-wavelength wavefront detection method, and the actual measurement result has larger errors (mainly contains systematic chromatic aberration).
3. The imaging lens is also a monochromatic system, in the process of multi-wavelength wavefront detection, the focal plane position of an interference image can be changed along with different wavelengths, the imaging lens is not easy to adjust in the measuring process, otherwise, a large optical axis offset error can be caused, although the imaging lens is not adjusted, the measuring result cannot be greatly influenced, the imaged edge is not clear, therefore, a mask is often required to be used for removing the unclear edge, and the measuring range is reduced.
In summary, the experimental apparatus is not a complete instrument, and is only suitable for experimental verification, and the problems of low efficiency, large error and the like exist in the measurement process, so that the multi-wavelength wavefront detection technology cannot be popularized and popularized in practice.
Disclosure of Invention
In order to solve the problems, the invention provides a multi-wavelength laser interference device, which adopts the following technical scheme:
the invention provides a multi-wavelength laser interference device, which is used for detecting the transmission wavefront of an optical system and is characterized by comprising the following components: the laser generating unit is used for generating at least four laser light sources with different wavelengths; the light source conversion unit is used for converting the laser light source into a point light source; the collimating unit is movably arranged on the guide rail mechanism and can move along the length direction of the guide rail mechanism, and is used for enabling the split light beams to form parallel light beams and emit the parallel light beams into the optical system, so that reference light beams and test light beams are formed by reflection; the diaphragm mechanism is used for filtering the reference light beam and the test light beam; the imaging unit is used for carrying out interference imaging on the filtered reference light beam and the filtered test light beam, wherein the collimating unit and the imaging unit both adopt achromatic systems, the four different wavelengths comprise at least one visible light wavelength and at least one near infrared wavelength, the achromatic systems carry out achromatization on one of the visible light wavelengths and one of the near infrared wavelengths, and the collimating unit is adjusted to enable the laser light sources of the achromatized visible light wavelengths and the near infrared wavelengths to be confocal.
The multi-wavelength laser interference device provided by the present invention may further have a technical feature in which, when the laser generation unit adjusts the wavelength of the generated laser light source, the position of the collimation unit on the guide rail mechanism is adjusted so that the focal points of the reference beam and the test beam are located at the diaphragm mechanism.
The multi-wavelength laser interference device provided by the invention can also have the technical characteristics that: the control unit comprises a mobile information storage part and a collimation control part, wherein the mobile information storage part at least stores each wavelength and the position information of the collimation units in one-to-one correspondence with the wavelength, and the collimation control part controls the collimation driving part to move the collimation units to corresponding positions according to the position information corresponding to the current wavelength.
The multi-wavelength laser interference device provided by the invention can also have the technical characteristics that: and the sensor is movably arranged on the guide rail assembly and used for receiving interference imaging to obtain an interference fringe image, wherein when the laser generation unit adjusts the wavelength of the generated laser light source, the position of the sensor on the guide rail mechanism is adjusted to enable the edge of the interference fringe image to be in a clear state.
The multi-wavelength laser interference device provided by the invention can also have the technical characteristics that: and the control unit comprises a sensor driving part for controlling the movement of the sensor, and the control unit comprises a sensor control part for controlling the sensor driving part to move the sensor to a position where the edge of the interference fringe image is clear.
The multi-wavelength laser interference device provided by the invention can also have the technical characteristics that the achromatic system is any one of a double-gluing structure, a triple-gluing structure, a double-separating structure, a gluing and separating structure, a separating and gluing structure and a triple-separating structure.
The multi-wavelength laser interference device provided by the invention can also have the technical characteristics that the achromatic visible light wavelength and the near infrared wavelength are 473nm and 1064nm respectively.
The multi-wavelength laser interference device provided by the invention can also have the technical characteristics that the laser generation unit comprises a plurality of lasers and a plurality of beam splitting prisms which are in one-to-one correspondence with the lasers, and the beam splitting prisms are used for deflecting the light beams emitted by the lasers to the light source conversion unit.
The multi-wavelength laser interference device provided by the invention can also have the technical characteristics that the laser generation unit further comprises a light source incidence bit for accessing laser with other wavelengths.
Action and Effect of the invention
According to the multi-wavelength laser interference device of the present invention, since the laser generating unit can generate a plurality of laser light sources of different wavelengths, it is possible to switch different wavelengths conveniently when detecting the transmitted wavefront. The laser light source converted into the point light source is refracted by the light splitting unit and then enters the collimation unit adopting the achromatic system, and the collimation unit is adjusted to enable the laser light source with the visible light wavelength and the laser light source with the near infrared wavelength to be confocal, so that when the multi-wavelength laser interference device is used, the corresponding infrared laser does not need to be adjusted, the visible light wavelength corresponding to the multi-wavelength laser interference device is directly adjusted, and the lens of the collimation unit can be adjusted along with the wavelengths due to the design, the moving distance of the lens is short, the generated optical axis deviation error is minimum, and the measuring result is more accurate. In addition, because the imaging lens also adopts an achromatic system, the structural design can effectively reduce the edge blurring of interference images caused by the change of imaging positions after the wavelength is changed.
Drawings
FIG. 1 is a diagram of a multi-wavelength laser interference device according to an embodiment of the present invention
FIG. 2 is a schematic structural diagram of a collimating unit and an imaging unit according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a 1-inch multi-wavelength laser interferometer according to one embodiment of the present invention;
FIG. 4 is a color focus shift plot of a 1-inch multi-wavelength laser interferometer in accordance with one embodiment of the present invention;
FIG. 5 is a dot-column diagram of the focus of a 1-inch multi-wavelength laser interferometer in accordance with one embodiment of the present invention;
FIG. 6 is a 473nm histogram of a 1-inch multi-wavelength laser interferometer according to one embodiment of the present invention;
FIG. 7 is a 532nm plot of a 1 inch multi-wavelength laser interferometer according to one embodiment of the present invention;
FIG. 8 is a 632.8nm point alignment diagram of a 1-inch multi-wavelength laser interferometer in accordance with one embodiment of the present invention;
FIG. 9 is a 721nm point diagram of a 1-inch multi-wavelength laser interferometer in accordance with one embodiment of the present invention;
FIG. 10 is a 1064nm spot diagram of a 1-inch multi-wavelength laser interferometer according to one embodiment of the present invention;
FIG. 11 is a structural diagram of a multi-wavelength laser interference device according to a second embodiment of the present invention;
FIG. 12 is a chromatic focal shift plot of a 2-inch multi-wavelength laser interferometer according to a second embodiment of the present invention;
FIG. 13 is a dot-column diagram of the focal point of the 2-inch multi-wavelength laser interferometer according to the second embodiment of the present invention;
FIG. 14 is a 473nm histogram of a 2-inch multi-wavelength laser interferometer in accordance with a second embodiment of the present invention;
FIG. 15 is a 532nm dot-column diagram of a 2-inch multi-wavelength laser interferometer in the second embodiment of the present invention;
FIG. 16 is a 632.8nm dot-column diagram of a 2-inch multi-wavelength laser interferometer in the second embodiment of the present invention;
FIG. 17 is a 721nm point diagram of a 2-inch multi-wavelength laser interferometer according to a second embodiment of the present invention;
FIG. 18 is a 1064nm spot diagram of a 2-inch multi-wavelength laser interferometer in accordance with the second embodiment of the present invention; .
Detailed Description
In order to make the technical means, the creation features, the achievement objects and the effects of the present invention easy to understand, the following embodiments and the accompanying drawings are used to specifically describe the multi-wavelength laser interference device of the present invention.
< example one >
Fig. 1 is a schematic structural diagram of a multi-wavelength laser interference device according to an embodiment of the present invention.
As shown in fig. 1, the multi-wavelength laser interference device 100 includes a laser generation unit 11, a light source conversion unit 12, a light splitting unit 13, a guide rail mechanism 14, a collimating unit 15, a diaphragm mechanism 16, an imaging unit 17, and a sensor 18.
The laser generating unit 11 is used for generating a plurality of laser light sources with different wavelengths. In this embodiment, the laser generating unit 11 generates laser beams with five wavelengths in total, which are laser beams with wavelengths of 473nm, 532nm, 632.8nm, 721nm and 1064nm in sequence (wherein 473nm, 532nm, 632.8nm and 721nm are visible light wavelengths, and 1064nm is a near-infrared wavelength). The lasers of these wavelength light sources have good single frequency and long coherence length, and the several wavelengths are far apart.
As shown in fig. 1, the laser generation unit 11 includes five lasers 111 and five beam splitting prisms 112 corresponding to the respective lasers 111 one by one. The arrangement sequence of the lasers 111 is determined according to the energy intensity of the lasers 111, and the beam splitter prism 112 is used for deflecting the light beam emitted from the corresponding laser 111 to the light source conversion unit 12.
In addition, the laser generating unit 11 further includes a reserved light source incident bit 113 for accessing laser with other wavelengths.
The light source conversion unit 12 is a point light source generator for forming the beamlets emitted by the laser 111 into a point light source having a certain numerical aperture.
The beam splitting unit 13 is a thin film beam splitter, and is used to bend a part of the light beam emitted from the point light source to form a split light beam, and the split light beam is incident to the collimating unit 15.
The guide rail mechanism 14 includes at least one parallel guide rail 141, and the length direction of the parallel guide rail 141 coincides with the optical path direction of the split light beam.
The collimating unit 15 is a collimating lens for making the split light source form a parallel light beam. The collimator unit 15 is movably provided on the parallel guide rail 141 and is movable in the longitudinal direction of the parallel guide rail.
In this embodiment, the parallel light beams emitted from the collimating unit 15 are incident into the optical system to be detected, and the optical system reflects the corresponding reference light beams and the corresponding test light beams according to the parallel light beams. Next, the reference beam and the test beam pass through the collimating unit 15, the beam splitting unit 13, the diaphragm mechanism 16, and the imaging unit 17 in this order, and are finally received by the sensor 18.
The diaphragm mechanism 16 is an aperture diaphragm, and is used for blocking stray light and playing a role in filtering.
The imaging unit 17 is used for imaging the reference beam and the test beam onto the sensor by interference to generate an interference fringe image.
In addition, the collimating unit 15 and the imaging unit 17 both use an achromatic system, which includes, but is not limited to, any one of a double cemented structure, a triple cemented structure, a double separated structure, a cemented and separated structure, a separated and cemented structure, and a three separated structure, as shown in fig. 2, and a maximum of 3 lenses may be used.
In this embodiment, both the collimating unit 15 and the imaging unit 17 are achromatic at 473nm and 1064nm, i.e., they are confocal at 473nm and 1064nm wavelengths.
The sensor 18 is a high-resolution CCD, and is configured to receive the interference image to obtain an interference fringe image, and transmit the interference fringe image to a computer for computational analysis, so as to obtain a transmitted wavefront of the optical system to be detected with a corresponding wavelength.
In the present embodiment, the diaphragm mechanism 16 and the imaging unit 17 are fixedly provided on the rail mechanism 14, and both are not movable in actual use. The collimating unit 15 and the sensor 18 are movably disposed on a parallel guide rail 141 of the guide rail mechanism 14, and the guide rail mechanism 14 further includes two movement adjusting mechanisms 142 respectively disposed corresponding to the collimating unit 15 and the sensor 18, so that a user can manually adjust the positions of the collimating unit 15 and the sensor 18 on the parallel guide rail through the movement adjusting mechanisms 142.
When the wavelength of the laser light source generated by the laser generating unit 11 changes (i.e., the laser generating unit 11 switches the laser 111 to be operated), only the position of the collimating unit 15 needs to be adjusted. Since the multi-wavelength laser interference device 100 is designed to be focused at 473nm and 1064nm in advance, when the position of the collimating unit 15 is adjusted to suit the laser light source with 473nm wavelength, the position of the collimating unit 15 is adjusted accordingly when the wavelength is 1064 nm.
When the wavelength is adjusted to another wavelength, the position of the collimating unit 15 is adjusted until the collimation of the reference beam is the best (observing the fringes using a shearing interferometer). The imaging unit 17 is designed to be in a fixed position, that is, only the collimating element 15 is adjusted when the wavelength changes, and the imaging position of each wavelength can still be ensured to be clear without adjusting the imaging unit 17 (this is because the embodiment designs a small-aperture interference system, the optimal focus displacement of the imaging mirror is small, so a comprehensive imaging position is selected, the optimal focus position of each wavelength is very close to this imaging position, the image quality can still be accepted, and within the diffraction limit, so the CCD does not need to be adjusted). And the collimating unit 15 and the imaging unit 17 adopt a double telecentric structure design so that the magnification of the interferogram of each wavelength changes very little when the wavelength changes. That is, only the collimating unit 15 is adjusted during the multi-wavelength measurement, and the interference image of each wavelength is clear and the image size is substantially consistent.
Although the position of the sensor 18 does not need to be adjusted when measuring the same system under test, the position of the sensor 18 (adjusted to a position where the edge of the interference image is clear) still needs to be adjusted when measuring other systems under test and the object distance is changed.
Next, in the first embodiment, a 1-inch multi-wavelength laser interferometer is taken as an example of the multi-wavelength laser interference device 100, and as shown in fig. 3, only the collimating unit 15 and the imaging unit 17 are shown in the figure for convenience of description.
In this embodiment, 473nm and 1064nm are achromatic, so that the distance to be moved during the adjustment of the collimating unit 15 from 473nm to 1064nm is the shortest, and the optical axis offset error of the system during measurement can be reduced. When the light source is replaced, the collimating unit 15 needs to be adjusted by 0.626mm in total. The back intercept of the collimating unit 15 at each wavelength is shown in table 1 below:
TABLE 11-inch rear intercept at 5 wavelengths of collimating units of multi-wavelength laser interferometers
| Wavelength (nm) | 473 | 532 | 632.8 | 721 | 1064 |
| Rear intercept (mm) | 146.564 | 146.169 | 145.941 | 145.938 | 146.564 |
Fig. 4 and 5 are point charts of the color focus shift curve and the focus of the collimating unit 15, respectively, and it can be seen from the diagrams that the foci of 473nm and 1064nm of the collimating unit 15 are focused at the same position, so that only 4 positions need to be adjusted for 5 wavelengths in the measurement process (after the collimation is adjusted at 473nm, the corresponding 1064nm is also collimated). It can be seen from the dot-column diagram that all wavelengths are very well focused at the focal point at the corresponding position, and the collimation of the reference beam is very good at the corresponding position.
Fig. 6 to 10 are dot charts of the multi-wavelength laser interference device 100 (1-inch multi-wavelength laser interferometer) for adjusting only the collimating unit 15 and not the sensor 18 (i.e., CCD) when the wavelength is changed at an object distance of 1000mm, and it can be seen that the imaging of the sensor 18 is very clear at each wavelength. And the collimating unit 15 and the imaging unit 17 adopt a double telecentric design, so that the edge field of view (image height) of the sensor 18 at different wavelengths is changed from 1.669mm to 1.7mm only (more is caused by diffraction, the larger the wavelength is, the larger the airy disc is). Therefore, in the process of multi-wavelength wavefront measurement, the generated system error is very small, and the multi-wavelength wavefront result can be measured more quickly and accurately.
< example two >
In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
The difference from the first embodiment is that the multi-wavelength laser interference apparatus of the second embodiment controls the movement of the collimating unit and the sensor through the electric driving member, and the 2-inch multi-wavelength laser interferometer is taken as an example for specific description in the second embodiment.
Fig. 11 is a schematic structural diagram of a multi-wavelength laser interference device according to a second embodiment of the present invention.
As shown in fig. 11, as shown in fig. 1, the multi-wavelength laser interference device 100 'includes a laser generating unit 11, a light source converting unit 12, a light splitting unit 13, a guide rail mechanism 14', a collimating unit 15, a diaphragm mechanism 16, an imaging unit 17, a sensor 18, and a control unit (not shown in the figure).
In the second embodiment, the rail mechanism 14' includes a parallel rail 141, a collimating driver 143, and a sensor driver 144.
The collimating driver 143 and the sensor driver 144 are each an electric driver (e.g., a driving motor) capable of driving the collimating unit 15 and the sensor 18, respectively, to move along the parallel guide rail 141 under the control of the control unit.
The control unit includes a movement information storage unit, a collimation control unit, and a sensor control unit.
The movement information storage unit stores the wavelengths of the laser light sources that can be generated by the laser generation unit 11 and the positional information of the collimation unit 15 corresponding to the respective wavelengths.
The position information is a position of the collimating unit 15 that needs to be adjusted under the corresponding wavelength, and in the second embodiment, the position information is a back intercept of the collimating unit, as shown in table 2 below:
TABLE 2.2-inch rear intercept of collimation system of multi-wavelength laser interferometer at 5 wavelengths
| Wavelength (nm) | 473 | 532 | 632.8 | 721 | 1064 |
| Rear intercept (mm) | 290.413 | 289.628 | 289.174 | 289.168 | 290.413 |
When the laser generating unit 11 adjusts the wavelength of the laser light source, the collimator driver 143 controls the collimator unit 15 to move to the corresponding position according to the above position information, and at the same time, the sensor driver 144 is manually controlled according to the sharpness of the interference pattern, that is, the sensor 18 is moved to a position where the edge of the interference fringe pattern is sharp.
In the second embodiment, the distance between the sensor 18 and the imaging unit 17 (the positions corresponding to different object distances are different, and the CCD can be adjusted by changing the object distance) is as shown in the following tables 3 and 4:
TABLE 3.2 inch multiple wavelength laser interferometer imaging distance of objective lens from CCD at 5 wavelengths (object distance 500mm)
| Wavelength (nm) | 473 | 532 | 632.8 | 721 | 1064 |
| Rear intercept (mm) | 15.176 | 15.116 | 15.082 | 15.082 | 15.176 |
TABLE 4.2 inch multiple wavelength laser interferometer imaging the distance between the objective and CCD at 5 wavelengths (object distance 200mm)
| Wavelength (nm) | 473 | 532 | 632.8 | 721 | 1064 |
| Rear intercept (mm) | 16.424 | 16.365 | 16.333 | 16.332 | 16.424 |
Fig. 12 and 13 are dot charts of the color focus shift curve and the focus of the collimating unit 15, respectively, and it can be seen from the diagrams that the foci of 473nm and 1064nm of the collimating unit 15 are focused at the same position, so that only 4 positions need to be adjusted for 5 wavelengths in the measurement process (after the collimation is adjusted at 473nm, the corresponding 1064nm is also collimated). It can be seen from the dot-column diagram that all wavelengths are very well focused at the focal point at the corresponding position, and the collimation of the reference beam is very good at the corresponding position.
Fig. 14 to 18 are dot charts of the multi-wavelength laser interference device 100 (2-inch multi-wavelength laser interferometer) adjusting the collimating unit 15 when the wavelength is changed and adjusting the sensor 18 (i.e., CCD) at an object distance of 500mm, and it can be seen that the imaging of the sensor 18 is very clear at each wavelength. As can be seen from tables 2, 3, and 4, the collimating unit 15 and the imaging unit 17 are also designed to be achromatic in the process of changing the wavelength during the adjustment process, but the imaging unit 17 is not designed separately, but is designed together with the collimating unit 15, and in the case of the adjustment distance corresponding to the collimating unit 15, the imaging unit 17 focuses at 473nm and 1064nm together (if designed separately, the position of the collimating unit 15 cannot be changed, so that 473nm and 1064nm together focus together), so that the adjustment distance required by the sensor 18 when changing the wavelength is the shortest, which also helps to reduce the system optical axis offset error. It can be seen from fig. 14 to 18 that not only the imaging of the sensor 18 is very clear, but also the maximum edge of the interference image is 1.7mm, thus ensuring that the wavefront with the same aperture is measured under each wavelength, reducing the system error due to the above factors, and improving the accuracy of the multi-wavelength wavefront measurement.
Examples effects and effects
According to the multi-wavelength laser interference device provided by the embodiment, the laser generating unit can generate laser light sources with various different wavelengths, so that different wavelengths can be conveniently switched when transmission wavefront detection is carried out, and the efficiency of multi-wavelength wavefront and other multi-wavelength parameter detection is greatly improved. Furthermore, because the light splitting unit refracts the laser light source converted into the point light source and then emits the laser light source into the collimating unit adopting the achromatic system, and the collimating unit is adjusted to enable the laser light source with visible light wavelength and near infrared wavelength to be confocal, when the multi-wavelength laser interference device is used, the corresponding infrared laser is not required to be adjusted, and the visible light wavelength corresponding to the multi-wavelength laser interference device is directly adjusted, and the design can ensure that the moving distance of the lens is shorter when the lens of the collimating unit is adjusted along with the wavelengths, so that the generated system optical axis deviation error is minimum, the measuring result is more accurate (the reason is that even if the lens is adjusted to be better, the collimator objective lens cannot be ensured to move along the Z axis due to the processing and adjusting errors of the lens during moving, so that an extremely small error (eccentric error) is caused, namely the measuring system is changed, i.e., the interferometric system measuring the wavefront at different wavelengths is changed, and as little displacement as possible reduces the generation of such errors). In addition, because the imaging lens also adopts an achromatic system, the structural design can effectively reduce the edge blurring of interference images caused by the change of imaging positions after the wavelength is changed.
In the embodiment, since the achromatization is performed for the two shortest and longest wavelengths in the multi-wavelength interferometer, namely, the achromatization at 473nm and the achromatization at 1064nm, when the laser light source is changed from the range of 473nm to 1064nm, the focal point displacement distance range of the collimation unit is the smallest, namely, the displacement distance required to be adjusted by the collimation unit is also the smallest, and the system error during measurement is further reduced.
In addition, the imaging system is also achromatic at 473nm and 1064nm, i.e., the two wavelengths are focused together. The main reasons are similar to the collimation system, and correspond to the collimation system, and if the CCD needs to be adjusted, the adjustment amount of the CCD can be minimized, and the system error is reduced.
In the embodiment, the laser generating unit is provided with a light source incident position for accessing laser with other wavelengths, so that lasers with other wavelengths can be conveniently added.
The above-described embodiments are merely illustrative of specific embodiments of the present invention, and the present invention is not limited to the description of the above-described embodiments.
For example, in the above-described embodiment, wavelengths of 473nm and 1064nm were achromatized. In other embodiments of the present invention, any of the 4 visible wavelengths may be used that is achromatic from 1064nm, which may result in an increase in the distance that the collimator needs to be moved during adjustment from 473nm to 1064nm, but still ensure the effect.
Claims (9)
1. A multi-wavelength laser interference device for detecting a transmitted wavefront of an optical system, comprising:
the laser generating unit is used for generating at least four laser light sources with different wavelengths;
the light source conversion unit is used for converting the laser light source into a point light source;
a light splitting unit for partially refracting the point light source to form a split light beam,
the length direction of the guide rail mechanism is consistent with the light path direction of the split light beam,
the collimating unit is movably arranged on the guide rail mechanism and can move along the length direction of the guide rail mechanism, and is used for enabling the split light beams to form parallel light beams and enter the optical system, so that the reference light beams and the test light beams are formed in a reflecting mode;
the diaphragm mechanism is used for filtering the reference light beam and the test light beam;
an imaging unit for interference imaging of the filtered reference beam and the test beam,
wherein the collimating unit and the imaging unit both employ achromatic systems,
the four different wavelengths include at least one visible wavelength and at least one near-infrared wavelength,
the achromatic system achromatizes one of the visible wavelengths and one of the near-infrared wavelengths,
the collimating unit is adjusted to co-focus the laser light sources of the achromatic visible and near-infrared wavelengths.
2. The multi-wavelength laser interference device according to claim 1, characterized in that:
wherein when the laser generating unit adjusts the wavelength of the generated laser light source, the position of the collimating unit on the guide rail mechanism is adjusted such that the focal points of the reference beam and the test beam are located at the diaphragm mechanism.
3. The multi-wavelength laser interference device according to claim 2, further comprising:
a control unit for controlling the operation of the display unit,
wherein the guide rail mechanism comprises a collimating drive for controlling movement of the collimating unit,
the control unit comprises a movement information storage part and a collimation control part,
the movement information storage unit stores at least the wavelengths and position information of the collimating units corresponding to the wavelengths one by one,
and the collimation control part controls the collimation driving part to move the collimation unit to a corresponding position according to the position information corresponding to the current wavelength.
4. The multi-wavelength laser interference device according to claim 2, further comprising:
a sensor movably arranged on the guide rail component and used for receiving the interference imaging to obtain an interference fringe image,
when the laser generation unit adjusts the wavelength of the generated laser light source, the position of the sensor on the guide rail mechanism is adjusted to enable the edge of the interference fringe image to be in a clear state.
5. The multi-wavelength laser interference device according to claim 4, further comprising:
a control unit for controlling the operation of the display unit,
wherein the guide rail mechanism comprises a sensor drive for controlling movement of the sensor,
the control unit includes a movement information storage section and a sensor control section,
the sensor control section controls the sensor driver to move the sensor to a position where an edge of the interference fringe image is clear.
6. The multi-wavelength laser interference device according to claim 1, characterized in that:
the achromatic system is any one of a double-gluing structure, a triple-gluing structure, a double-separating structure, a gluing and separating structure, a separating and gluing structure and a triple-separating structure.
7. The multi-wavelength laser interference device according to claim 1, characterized in that:
wherein the achromatic visible and near infrared wavelengths are 473nm and 1064nm, respectively.
8. The multi-wavelength laser interference device according to claim 1, characterized in that:
wherein the laser generating unit comprises a plurality of lasers and a plurality of beam splitting prisms corresponding to the lasers one by one,
the beam splitter prism is used for deflecting the light beam emitted by the laser to the light source conversion unit.
9. The multi-wavelength laser interference device according to claim 8, characterized in that:
the laser generation unit also comprises a light source incidence bit used for accessing laser with other wavelengths.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101509828A (en) * | 2009-03-06 | 2009-08-19 | 北京理工大学 | Differential confocal-low coherent interference combination refractivity and thickness measurement method and apparatus |
| JP2009192249A (en) * | 2008-02-12 | 2009-08-27 | Hoya Corp | Method and device for measuring transmission wave front aberration of test lens |
| CN104111163A (en) * | 2014-07-23 | 2014-10-22 | 中国科学院上海光学精密机械研究所 | Convex lens focal length measuring device and method |
| JP2015129674A (en) * | 2014-01-07 | 2015-07-16 | オリンパス株式会社 | spectral transmittance measurement device |
| CN106197258A (en) * | 2016-07-14 | 2016-12-07 | 中国科学院上海光学精密机械研究所 | Dual pathways dual wavelength interference checking device |
| CN106404354A (en) * | 2016-10-11 | 2017-02-15 | 中国科学院长春光学精密机械与物理研究所 | Device and method for measurement of aspheric compensator transmission wavefront equation |
| CN207095826U (en) * | 2017-08-22 | 2018-03-13 | 苏州维纳仪器有限责任公司 | For detecting the interference device and its system of any wavelength optical system transmission wavefront |
| CN109029244A (en) * | 2018-07-10 | 2018-12-18 | 中国科学院上海光学精密机械研究所 | Multiwavelength laser interferometer |
| CN110307962A (en) * | 2019-06-28 | 2019-10-08 | 苏州维纳仪器有限责任公司 | The method of any wavelength transmission wavefront of detection optical system |
-
2021
- 2021-08-05 CN CN202110896803.XA patent/CN113624456A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009192249A (en) * | 2008-02-12 | 2009-08-27 | Hoya Corp | Method and device for measuring transmission wave front aberration of test lens |
| CN101509828A (en) * | 2009-03-06 | 2009-08-19 | 北京理工大学 | Differential confocal-low coherent interference combination refractivity and thickness measurement method and apparatus |
| JP2015129674A (en) * | 2014-01-07 | 2015-07-16 | オリンパス株式会社 | spectral transmittance measurement device |
| CN104111163A (en) * | 2014-07-23 | 2014-10-22 | 中国科学院上海光学精密机械研究所 | Convex lens focal length measuring device and method |
| CN106197258A (en) * | 2016-07-14 | 2016-12-07 | 中国科学院上海光学精密机械研究所 | Dual pathways dual wavelength interference checking device |
| CN106404354A (en) * | 2016-10-11 | 2017-02-15 | 中国科学院长春光学精密机械与物理研究所 | Device and method for measurement of aspheric compensator transmission wavefront equation |
| CN207095826U (en) * | 2017-08-22 | 2018-03-13 | 苏州维纳仪器有限责任公司 | For detecting the interference device and its system of any wavelength optical system transmission wavefront |
| CN109029244A (en) * | 2018-07-10 | 2018-12-18 | 中国科学院上海光学精密机械研究所 | Multiwavelength laser interferometer |
| CN110307962A (en) * | 2019-06-28 | 2019-10-08 | 苏州维纳仪器有限责任公司 | The method of any wavelength transmission wavefront of detection optical system |
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