CN220323642U

CN220323642U - Optical system assembly and laser optical system

Info

Publication number: CN220323642U
Application number: CN202322063208.5U
Authority: CN
Inventors: 徐炳蔚; 朱欣
Original assignee: Femtosecond Research Center Co Ltd
Current assignee: Femtosecond Research Center Co Ltd
Priority date: 2023-08-02
Filing date: 2023-08-02
Publication date: 2024-01-09
Anticipated expiration: 2033-08-02

Abstract

The present application relates to an optical system assembly and a laser optical system; in the 4f system, a first optical device is arranged on a first mobile unit, a second optical device is arranged on a second mobile unit, and a third optical device is arranged on a fixed part; the first optical device, the second optical device and the third optical device are positioned on the main optical axis and positioned in the same plane perpendicular to the base platform; the structure that the first moving unit moves linearly along the main optical axis direction on the base platform, the second moving unit moves linearly along the main optical axis direction on the first moving unit, and the fixing part is arranged on the base platform is designed; according to the technical scheme, the optical systems with different requirements can be flexibly and accurately combined and configured, the optical performance requirements in different fields are met, the structural design is concise, and the parameter adjustment operation is convenient.

Description

Optical system assembly and laser optical system

Technical Field

The application relates to the technical field of optics, in particular to an optical system component and a laser optical system.

Background

Fourier optics is the theoretical basis of instruments such as a phase contrast microscope and a schlieren, and an optical system for realizing an optical neural network, called an optical computer, can be built by expanding optical technology and utilizing devices such as binary optics, is not limited by hardware speed, and has the characteristic of real-time calculation; as shown in fig. 1, fig. 1 is a schematic structural diagram of an exemplary fourier optical system, which implements a fourier 4f transform function, where each distance in the diagram is a focal length f, and the total distance is 4f, which is called a 4f system, where P1, L1, P2, L2, and P3 are optical devices, and the distance between each is the focal length f; generally, L1 and L2 are lenses, for example, P1 is an object plane, a focal plane of the lens L1 is a spectrum of the object plane (i.e., fourier transform of the object plane), and spatial filtering and other operations can be performed on the plane, and then the lens L2 is used to image the plane P2, so as to obtain an optical system with mathematical analog operation capability, where common components of the fourier optical system include various lens elements, gratings, spatial light modulators (Spatial light modulator, SLM), and the like.

In the above fourier optical system, once the combination of different components such as the lens element, the grating and the spatial light modulator is set, the structure of the optical system cannot be changed at will, when other functional requirements are required to be compatible, even if the specific parameters of the functional requirements are not different from the requirements set by the original combination, the original combination design must be changed substantially, the 4f system design is usually complex, the optical elements are more, in order to ensure the performance of the optical system, all 4f distances often need to be accurately adjusted, the manpower and time costs are high when the existing optical system is adjusted, and the application requirements are difficult to meet.

Disclosure of Invention

Based on this, it is necessary to provide an optical system assembly and a laser optical system aiming at least one of the above technical defects, which provide an assembly with flexible combination and convenient adjustment for the construction of the optical system, and reduce the adjustment cost.

An optical system assembly, comprising: the base platform, locate first mobile unit and fixed part on the base platform, and locate the second mobile unit on the first mobile unit;

the first moving unit is provided with a first optical device, the second moving unit is provided with a second optical device, and the fixed part is provided with a third optical device;

the first optical device, the second optical device and the third optical device are positioned on the main optical axis and positioned in the same plane vertical to the base platform;

the first moving unit moves linearly along the main optical axis direction on the base platform, the second moving unit moves linearly along the main optical axis direction on the first moving unit, and the fixing part is arranged on the base platform;

the incident light ray sequentially passes through the third optical device, the first optical device and the second optical device for optical treatment; the emergent light rays sequentially pass through the second optical device, the first optical device and the third optical device and then are emitted.

In one embodiment, the first optical device is a lens element, the second optical device is a spatial light modulator, and the third optical device is a grating;

the incident light is separated from the grating and then enters the spatial light modulator to be modulated after being converted into parallel light through the lens element; the emergent light rays return from the spatial light modulator and are converged by the lens element and then are combined and emitted by the grating.

In one embodiment, a first track is arranged on the base platform, the first moving unit moves linearly along the first track in the direction of the main optical axis, and the distance between the lens element and the grating is adjusted;

the first moving unit is provided with a second track, and the second moving unit moves linearly along the second track in the main optical axis direction to finely adjust the distance between the space light modulator and the lens element.

In one embodiment, the optical system assembly further comprises: a first mirror, a second mirror, and a third mirror mounted on the base platform; wherein the first, second and third mirrors are located in a plane perpendicular to the base platform;

the incident light rays sequentially enter the grating after being reflected by the first reflecting mirror and the third reflecting mirror; the emergent light is output by the grating and then sequentially emitted by the third reflector and the second reflector.

In one embodiment, the first reflecting mirror and the second reflecting mirror are positioned at different height positions of the same position point in the plane of one base platform; the contact position of the light rays and each reflecting mirror is the edge position of the reflecting mirror.

In one embodiment, the optical system assembly further comprises: further comprises: a fourth reflector disposed on the base platform;

after the incident light is reflected by the third reflecting mirror, the incident light enters the grating through the reflection of the fourth reflecting mirror; the emergent light is output by the grating, passes through the fourth reflector and then enters the third reflector to be reflected.

In one embodiment, the optical system assembly further comprises an upper pitching stage mounted on the fixed part, and the grating is mounted on the pitching stage through a rotating structure; the pitching platform is used for continuously adjusting the pitch angle of the grating, and the rotating structure is used for adjusting the horizontal angle of the grating on the plane of the pitching platform.

In one embodiment, the pitching platform comprises a square structure, the lower side surface of the square structure is connected with the upper end of the fixed part, and the upper side surface is connected with the grating through the rotating structure;

an expansion bolt and a contraction bolt are arranged between the lower side surface and the upper side surface; the expansion bolts are used for providing internal expansion stress to enable the lower side face and the upper side face of the square-shaped structure to expand outwards, and the contraction bolts are arranged at two ends of the opening of the square-shaped structure and used for providing opposite direction stress to enable the lower side face and the upper side face of the square-shaped structure to contract inwards; when the stress of the expansion bolt and the stress of the contraction bolt are equal, locking the posture of the pitching platform;

the rotating structure comprises a separating piece connected to the upper side surface and a freely rotating disc below the separating piece, and the grating is connected to the disc and used for controlling the free rotation angle of the grating; the disc is locked by a fixing bolt.

In one embodiment, the base platform is provided with high precision scales on both sides for indicating the distance of the spatial light modulator and the lens element relative to the grating.

In one embodiment, the incident light is a laser pulse, the lens element is a cylindrical lens or a spherical lens, and the spatial light modulator is a two-dimensional liquid crystal spatial light modulator.

A laser optical system comprising: a laser, and said optical system assembly; the laser outputs laser pulses, and the laser pulses are modulated by the optical system component and then output for application.

In the 4f system, the first optical device is installed on the first moving unit, the second optical device is installed on the second moving unit, and the third optical device is installed on the fixing part; the first optical device, the second optical device and the third optical device are positioned on the main optical axis and positioned in the same plane perpendicular to the base platform; the structure that the first moving unit moves linearly along the main optical axis direction on the base platform, the second moving unit moves linearly along the main optical axis direction on the first moving unit, and the fixing part is arranged on the base platform is designed; according to the technical scheme, the optical systems with different requirements can be flexibly and accurately combined and configured, the optical performance requirements in different fields are met, the structural design is concise, and the parameter adjustment operation is convenient.

Further, the first optical device is a lens element, the second optical device is a spatial light modulator, and the third optical device is a grating; a lens element is mounted on the first moving unit, a spatial light modulator is mounted on the second moving unit, and a grating is mounted on the fixed portion; the first moving unit is adjusted to linearly move on the base platform along the direction of the main optical axis, and the second moving unit is adjusted to linearly move on the first moving unit along the direction of the main optical axis; therefore, the adjustment of different parameters among the spatial light modulator, the lens element and the grating is realized, the labor and time cost of system adjustment is reduced, and the application requirements are better met.

Drawings

FIG. 1 is a schematic diagram of an exemplary Fourier optical system;

FIG. 2 is a schematic diagram of an exemplary optical system assembly;

FIG. 3 is a schematic view of an exemplary pitch station configuration;

FIG. 4 is a schematic view of another exemplary pitch station configuration;

FIG. 5 is a schematic illustration of an exemplary optical path;

fig. 6 is a top plan view of an example.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.

It should be noted that, due to space limitation, all technical solutions cannot be enumerated, only some embodiments are provided in the following examples, and the "first" and "second" described in the present application are used only to distinguish different objects, and have no substantial distinguishing meaning.

Referring to fig. 2, fig. 2 is a schematic view of an exemplary optical system assembly structure, the assembly comprising: a base platform 20, a first moving unit 30 and a fixing portion 21 provided on the base platform 20, and a second moving unit 31 provided on the first moving unit 30, the fixing portion 21 being provided on the base platform 20; the first moving unit 30 is designed as a large slider, the second moving unit 31 is a small slider, the first moving unit 30 is provided with a lens element (first optical device) 301, the second moving unit 31 is provided with a spatial light modulator (second optical device) 311, and the fixed part 21 is provided with a grating (third optical device) 211; the spatial light modulator 311, the lens element 301 and the grating 211 are located on the main optical axis and in a plane perpendicular to the base platform 20, combined into one optical computing system.

From the light path, the incident light sequentially passes through the third optical device, the first optical device and the second optical device for optical treatment; the emergent light rays sequentially pass through the second optical device, the first optical device and the third optical device and then are emitted. According to the technical scheme, the optical systems with different requirements can be flexibly and accurately combined and configured, the optical performance requirements in different fields are met, the structural design is concise, and the parameter adjustment operation is convenient.

In the above embodiment, for convenience of description of the embodiment, the lens element 301 correspondingly represents the first optical device, the spatial light modulator 311 correspondingly represents the second optical device, and the grating 211 correspondingly represents the third optical device; of course, other optical devices may be used for the first optical device, the second optical device, and the third optical device, and the principle is basically consistent, which is not described in detail herein.

Wherein the first moving unit 30 is designed to move linearly in the main optical axis direction on the base platform 20, and the second moving unit 31 is designed to move linearly in the main optical axis direction on the first moving unit 30.

Illustratively, a first rail 30a is provided on the base platform 20, and the first moving unit 30 is embedded in the first rail 30a, and can perform linear motion along the first rail 30a in the main optical axis direction, as shown in the figure, and perform left-right linear motion, so as to adjust the distance between the lens element 301 and the grating 211; meanwhile, the first moving unit 30 is provided with a second rail 31a, and the second moving unit 31 is embedded in the second rail 31a, and can perform linear motion along the second rail 31a in the main optical axis direction, thereby performing fine adjustment of the distance between the spatial light modulator 311 and the lens element 301.

When in use, incident light enters the optical computing system from the grating 211, the light is separated by the grating 211, then enters the spatial light modulator 311 for modulation after being converted into parallel light by the lens element 301, the modulated emergent light is obtained, the emergent light returns from the spatial light modulator 311, is converged by the lens element 301 and then is combined and emitted by the grating 211, namely, the emergent light returns in a 'primary path'.

Above mentioned real worldIn the structure of the embodiment, the grating 211 is a dispersive element that can disperse a high-power laser light; for example, in the field of high-power lasers, high-energy light pulses are dispersed in time by the grating 211 to generate pulses having a pulse width of the order of femtoseconds (10 ^-15 ) Is a laser of (2); the spatial light modulator 311 is a device that is preprogrammed to dynamically change the temporal and spatial characteristics of the light wave, and the light wave modulation is achieved by specifically modulating one or more parameters in the light field (such as light field amplitude, refractive index, phase, polarization state, and conversion of incoherent/coherent light), in which embodiment the spatial light modulator 311 may be a two-dimensional liquid crystal spatial light modulator 311 (2D-SLM); the lens element 301 is a conventional optical device, and in this embodiment, the lens element 301 may be a spherical lens or a cylindrical lens, preferably, in the embodiment, a cylindrical lens is selected, and the cylindrical lens has a single main optical axis, which may be used for the image aspect ratio and the astigmatic adjustment operation.

As shown in fig. 2, a first moving unit 30 and a second moving unit 31 which are slidable left and right are provided on the base stage 20 in the main optical axis direction, and a lens element 301 and a spatial light modulator 311 are mounted on the same horizontal level, and both the first moving unit 30 and the second moving unit 31 are slidable along the main optical axis, so that positions among the spatial light modulator 311, the lens element 301, and the grating 211 are continuously accurate. By the above structural design, a plurality of parameters of the optical system, such as the fourier optical system, can be simply and accurately flexibly adjusted, the first moving unit 30 is adjusted so that the position of the grating 211 is just at the focus of the lens element 301, and the lens element 301 and the spatial light modulator 311 are adjusted to achieve the optimal focal length.

In practical applications, an angle may exist between the outgoing light passing through the grating 211 and the horizontal plane, for example, the grating 211 is not parallel to the gravity plumb line, and the grating 211 is processed with flaws, so that the combination performance of the lens element 301 and the grating 211 is reduced due to the influence of external environment (such as wind speed and temperature) fluctuation, and the fourier optical system is disabled.

Accordingly, in one embodiment, the pitching stage 22 is provided on the fixing portion 21, the grating 211 is mounted on the upper end of the pitching stage 22, the pitch angle of the grating 211 can be continuously adjusted by the pitching stage 22, and simultaneously, in order to adjust the angle of the grating 211 on the horizontal plane, the grating 211 is mounted on the pitching stage 22 in a freely rotating manner, so that the grating 211 can adjust the horizontal angle of the grating 211 on the plane of the pitching stage 22. Through the combined adjustment of the pitch angle and the horizontal angle, the purpose of adjusting the spatial attitude parameter of the grating 211 is achieved, and finally, the incident light rays vertically enter the lens element 301 after exiting from the grating 211.

As for the structure of the pitching stage 22, which is mounted on the upper end of the fixed portion 21, as shown in fig. 3, fig. 3 is a schematic view of an exemplary pitching stage structure, and as shown in fig. 3 (a), the grating 211 is mounted on the pitching stage 22 by a rotation structure 231; wherein the pitching stage 22 is used for continuously adjusting the pitch angle of the grating 211, and the rotating structure 231 is used for adjusting the horizontal angle of the grating 211 on the plane of the pitching stage 22.

Illustratively, the pitching platform 22 may include a rectangular structure 224, wherein a lower side 224a of the rectangular structure 224 is connected to an upper end of the fixed portion 22, and an upper side 224b is connected to the grating 211 through a rotating structure 231; an expansion bolt 225 and a contraction bolt 226 are arranged between the lower side 224a and the upper side 224 b; the expansion bolts 225 are used for providing internal expansion stress to promote the lower side 224a and the upper side 224b of the square-shaped structure 224 to expand outwards, and the contraction bolts 226 are arranged at two ends of the opening of the square-shaped structure 224 and used for providing opposite direction stress to promote the lower side 224a and the upper side 224b of the square-shaped structure 224 to contract inwards; when the stress of the expansion bolts 225 and the contraction bolts 226 is appropriate, the pitching table 22 is locked in posture.

As shown in fig. 3 (b), the rotation structure 231 may include a spacer 227 connected to the upper side 224b and a freely rotatable disk 228 below the spacer, and the grating 211 is connected to the disk 228 for controlling a free rotation angle of the grating 211; the disc 228 is locked by a fixing bolt 228 a.

In addition, for the structure of the pitching platform 22, as shown in fig. 4, fig. 4 is a schematic diagram of another example pitching platform structure, in the design of fig. 4 (a), the rectangular structure 224 adopts a different grating pitching locking mechanism, wherein a spring 229a is connected between two ends of the opening of the rectangular structure 224, which provides a tightening force for inward contraction of the lower side 224a and the upper side 224b of the rectangular structure 224, and then adopts a rigid metal sphere 229b to realize an expansion force, and when the two forces are the same, locking is realized; in addition, as in FIG. 4 (b), expansion bolts 225 may also be used to provide internal expansion stresses, effecting pitch locking.

In the solution of the foregoing embodiment, since the spatial light modulator 311, the lens element 301 and the grating 211 are located in one plane (1) perpendicular to the base platform 20, and the grating 211 is directly mounted on the pitching platform 22, it is ensured that when the grating 211 performs parameter adjustment in any 3D direction, the spatial light modulator 311 and the lens element 301 above the first moving unit 30 are always kept coaxial, so that the outgoing light and the lens element 301 are in a mutually perpendicular state in space, and the combination performance of the two is ensured not to be affected by external environmental fluctuation.

In one embodiment, in the fourier optical system formed based on the optical system component 02 of the present application, in order to facilitate parameter adjustment among the spatial light modulator 311, the lens element 301 and the grating 211, the position of the grating 211 is adjusted to fall on the focal point of the lens element 301, so that the solution of the present embodiment may further be provided with high-precision scales 203 on two sides of the base platform 20, so as to accurately indicate the distances between the spatial light modulator 311 and the lens element 301 relative to the grating 211; correspondingly, fine adjustment is performed in the edge range of the factory parameters of the lens element 301 during adjustment, and the state of the emergent light is observed, and the actual focal length is determined when the emergent light reaches the optimum.

For the optical path design of the incident light ray and the emergent light ray, in order to match the parameter adjustment performance of the optical system component 02 in the above embodiment, the present application further provides the following embodiments.

In one embodiment, the first mirror 101, the second mirror 102, and the third mirror 103 are mounted at set height positions on the base platform 20; the first mirror 101, the second mirror 102 and the third mirror 103 lie in a plane perpendicular to the base platform 20; the incident light rays sequentially enter the grating 211 after being reflected by the first reflecting mirror 101 and the third reflecting mirror 103; after being output by the grating 211, the outgoing light is sequentially emitted through the third mirror 103 and the second mirror 102. Wherein the first reflecting mirror 101 and the second reflecting mirror 102 are positioned at different height positions of the same position point in the plane (2) of one base platform 20; the contact position of the light rays and each reflecting mirror is the edge position of the reflecting mirror.

In addition, a fourth mirror 104 may be installed as needed; correspondingly, after being reflected by the third reflecting mirror 103, the incident light enters the grating 211 by the reflection of the fourth reflecting mirror 104; the outgoing light is output from the grating 211, passes through the fourth mirror 104, and then enters the third mirror 103 to be reflected.

For the optical paths of the above embodiments, referring to fig. 5, fig. 5 is a schematic view of an exemplary optical path in which the viewing angle is in an outward direction from the side close to the mirror, i.e., a→b direction in fig. 2, as shown in the figure, the incident light is reflected by the first mirror 101, the third mirror 103, and the fourth mirror 104 to enter the grating 211; meanwhile, after exiting from the grating 211, the outgoing light is sequentially emitted through the fourth mirror 104, the third mirror 103, and the second mirror 102.

For an optical computing system composed of the spatial light modulator 311, the lens element 301, and the grating 211, which is located at a position of a plane (1) perpendicular to the base platform 20 and a plane (2) of the base platform 20 perpendicular to the mirrors 101 to 104, referring to fig. 6, fig. 6 is a top plan view of an example, in which the angle of view is a top plan direction from top to bottom, i.e., a direction C to a in fig. 2, as shown in the drawing, the mirrors 101 to 104 are located on the base platform 20, an appropriate optical path may be set as required, and the mirrors may be installed at appropriate height positions so that incident light enters from the first mirror 101 and exits from the second mirror 102 (outgoing light is omitted in the drawing).

Through the structural design of a plurality of reflectors, a plurality of different types of light path designs can be compatible, light path designs with different requirements are formed, an external light source or processed incident light enters the grating 211 through the first reflector 101, the third reflector 103 and the fourth reflector 104 in sequence, the emergent light leaves the grating 211 through the optical computing system combined by the grating 211, the lens element 301 and the spatial light modulator 311 which are set in advance, and then the emergent light sequentially passes through the fourth reflector 104, the third reflector 103 and the second reflector 102, so that specific design targets and beam performance parameters are realized and then the emergent light is emitted to a subsequent application scene for use.

Preferably, each of the reflectors 101 to 104 may be a square reflector, and in the relevant optical path of the reflector, the contact position between the light and each reflector is designed at the right edge position of each reflector through corresponding parameter calculation, so as to ensure that the incident light and the emergent light just avoid, thereby reducing accidental fluctuation and improving the stability and the corresponding compatibility of the optical system.

According to the technical scheme of the embodiments, the combination of the mobile unit, the optical device and the reflecting mirror is equivalent to a folding 4f system, so that the design structure is simplified, the cost of the optical element is saved, and the adjustment process can be completed by only adjusting two f distances when the optical element is used. The distance between the lens element and the spatial light modulator can be accurately adjusted through the second moving unit, and the distance between the lens element and the grating can be accurately adjusted through the first moving unit; the operation is convenient and efficient on the premise of the same precision; in addition, the structural design can ensure that an incident light path and an emergent light path are mutually free from interference, and the relevant application requirements of the Fourier 4f system are met pertinently.

An embodiment of the laser optical system is set forth below.

The present embodiment provides a laser optical system, as shown in fig. 3, including: a laser 01, and an optical system assembly 02 of any of the above embodiments; the laser 01 outputs a laser pulse, and the laser pulse is modulated by the optical system component 02 and then output for application.

In summary, the present application provides the configuration and performance expansion of the 4f fourier optical system, designs the optical system component 02 with simple structure, comprehensive functions and convenient control and parameter adjustment, and can construct different fourier optical systems through the component, so as to effectively cover the functional demands of the systems in a plurality of related application fields.

The above examples merely represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the utility model. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application is to be determined by the claims appended hereto.

Claims

1. An optical system assembly, comprising: the base platform, locate first mobile unit and fixed part on the base platform, and locate the second mobile unit on the first mobile unit;

2. The optical system assembly of claim 1, wherein the first optical device is a lens element, the second optical device is a spatial light modulator, and the third optical device is a grating;

3. The optical system assembly of claim 2, wherein the base platform is provided with a first rail, and the first moving unit moves linearly along the first rail in the direction of the main optical axis to adjust the distance between the lens element and the grating;

4. The optical system assembly of claim 2, further comprising: a first mirror, a second mirror, and a third mirror mounted on the base platform; wherein the first, second and third mirrors are located in a plane perpendicular to the base platform;

5. The optical system assembly of claim 4, wherein the first mirror and the second mirror are positioned at different heights from a same location point in a plane of a base platform; the contact position of the light rays and each reflecting mirror is the edge position of the reflecting mirror.

6. The optical system assembly of claim 2, further comprising: a fourth reflector disposed on the base platform;

7. The optical system assembly of claim 2, further comprising an upper pitch stage mounted to the stationary portion, the grating being mounted to the pitch stage by a rotating structure; the pitching platform is used for continuously adjusting the pitch angle of the grating, and the rotating structure is used for adjusting the horizontal angle of the grating on the plane of the pitching platform.

8. The optical system assembly of claim 7, wherein the pitch stage comprises a loop-shaped structure, a lower side of the loop-shaped structure being connected to an upper end of the fixed portion, and an upper side being connected to the grating by the rotating structure;

9. The optical system assembly of claim 1, wherein the base platform is provided with high precision scales on both sides for indicating the distance of the spatial light modulator and the lens element relative to the grating.

10. A laser optical system, comprising: a laser, and an optical system assembly according to any one of claims 1-9; the laser outputs laser pulses, and the laser pulses are modulated by the optical system component and then output for application.