Diffractive field printing system and optical output method

Abstract

The present application relates to a diffraction field printing system and an optical output method, comprising a light source, an illumination optical subsystem, an imaging optical subsystem, a reference light subsystem, a mechanical motion subsystem and a control subsystem, the light emitted by the light source is split into a first illumination light field and a second illumination light field; the imaging optical subsystem comprises a diffractive optical device, a spatial light modulator and a Fourier transform lens, the spatial light modulator is located at the input face of the Fourier transform lens, used for modulating data structure, and forming the sub-wavefront information of the diffraction field on the output face of the Fourier transform lens, the first illumination light field forms a limited band dissipation spot and a Gaussian-removed light field on the input face and the output face of the Fourier transform lens; the reference light subsystem comprises a galvanometer and a relay lens group, the second illumination light field forms a reference light field on the output face of the relay lens group, and the light spot formed by the light field coincides with the output face of the Fourier transform lens or the image face of the output face. The formed diffraction field has high signal-to-noise ratio and strong uniformity.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of printing technology, and particularly relates to a diffraction field printing system and an optical output method. BACKGROUND

[0002] Diffraction field has wide applications in 3D display and sensing, photon technology, precision measurement and other fields. How to accurately construct controllable diffraction field, especially large-area functional diffraction field, is an important challenge in the field. Current construction technologies mainly include spatial light modulation technology, photolithography technology, holographic exposure technology, etc. Spatial light modulation technology mainly uses liquid crystal display, liquid crystal on silicon (LCOS) display and other devices to display complex amplitude images with different distributions, and then constructs diffraction field through the diffraction of complex amplitude images on light waves. This technology can realize specific diffraction field by adjusting the amplitude or phase of each pixel. However, the angle distribution of the diffraction field and the output area of the diffraction field are limited by the spatial light modulation device.

[0003] Photolithography technology can flexibly construct various diffraction fields by etching diffraction structures on the surface of a substrate. However, the diffraction structure needs a large amount of complex complex number operation to obtain its structure data, and the data volume is huge. A large-angle diffraction field requires its pixel unit to be below sub-micron. Preparing such a scale diffraction structure requires expensive photolithography equipment, and the width is restricted by the size of the wafer and the photolithography equipment, so it is difficult to realize the output of large-area diffraction field for display.

[0004] Traditional holographic exposure technology records holographic fringes on a dry plate through processes such as exposure and development, to realize the recording of diffraction field. Then the output of diffraction field is realized through the diffraction of holographic fringes. This technology can realize large-area and large-angle diffraction field, but its manufacturing process is complex, and requires the support of strict working conditions and equipment such as vibration isolation platform, vibration isolation laboratory, high-power high-coherence laser, etc. Moreover, there are problems such as digitalization difficulty. The digital holographic technology developed on this basis uses numerical calculation instead of holographic exposure, which reduces the dependence on vibration isolation environment, but requires high-performance professional computing equipment for support, and the output process of diffraction structure is also severely restricted by the resolution of the output system. More importantly: whether it is traditional holography or digital holography, the diffraction field constructed will be polluted by speckle noise and disturbed by Gaussian distribution, and the quality of the diffraction field is limited. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a diffraction field printing system and an optical output method, which can realize the output of large-area and high-quality functional diffraction field, and can form an optical field distribution that realizes speckle noise elimination and Gaussian elimination in near field and far field.

[0006] In order to solve the above technical problems, the application provides a diffraction field laser printing system, which comprises a light source, an illumination optical subsystem, an imaging optical subsystem, a reference light subsystem, a mechanical motion subsystem and a control subsystem, the illumination optical subsystem comprises a beam splitter, light emitted by the light source enters the illumination optical subsystem and is split into a first illumination light field and a second illumination light field by the beam splitter; the imaging optical subsystem comprises a diffractive optical device, a spatial light modulator and a Fourier transform lens, the spatial light modulator is located at the input face of the Fourier transform lens, the spatial light modulator is used for modulating data structures corresponding to sub-wavefront information and forming the sub-wavefront information of the diffraction field on the output face of the Fourier transform lens, wherein the first illumination light field illuminates the imaging optical subsystem, so that the first illumination light field sequentially passes through the diffractive optical device, the spatial light modulator and the Fourier transform lens, and a limited-band diffraction-limited spot and a Gaussian-removed light field distribution are formed on the input face and the output face of the Fourier transform lens; the reference light subsystem comprises a galvanometer and a relay lens group, the second illumination light field enters the reference light subsystem, so that the second illumination light field sequentially passes through the galvanometer and the relay lens group, and a reference light light field is formed on the output face of the relay lens group; wherein the light spot formed by the reference light light field coincides with the output face of the Fourier transform lens or the image face of the output face; the mechanical motion subsystem comprises a galvanometer driving device and a translation device, the galvanometer driving device is used for driving the galvanometer to rotate in two dimensions; the translation device is used for driving the diffractive optical device to move horizontally; the translation device is also used for driving the diffraction field recording material to move horizontally, wherein the photosensitive face of the diffraction field recording material coincides with the output face of the Fourier transform lens or the image face of the output face; the control subsystem is used for controlling the image refresh of the spatial light modulator and the motion of the mechanical motion subsystem.

[0007] The diffractive optical device is used for controlling the uniform distribution of the energy of the light spot.

[0008] The translation device comprises a one-dimensional translation stage, a two-dimensional translation stage, the one-dimensional translation stage comprises a one-dimensional precision translation stage, and the two-dimensional translation stage comprises a two-dimensional precision translation stage.

[0009] The imaging optical subsystem further comprises a micro-imaging lens group, the micro-imaging lens group is used for imaging the output face of the Fourier transform lens to the photosensitive face of the diffraction field recording material, and forming the image face of the output face.

[0010] The imaging optical subsystem further comprises any one or several of a field stop, an automatic focusing light path and a real-time monitoring light path; the field stop is used for controlling the size of the diffraction pixel of the recording unit of the diffraction field; the automatic focusing light path is used for ensuring that the output face of the Fourier transform lens or the image face of the output face is focused near the surface of the diffraction field recording material.

[0011] The reference light subsystem further comprises an aperture stop, the aperture stop is used for controlling the shape and size of the light spot formed by the reference light.

[0012] The mechanical movement subsystem further comprises a translational mechanism and / or a rotating mechanism, the translational mechanism is used to drive the spatial translation of the diffractive optical device, and the rotating mechanism is used to drive the spatial rotation of the diffractive optical device. When the mechanical movement subsystem comprises both the translational mechanism and the rotating mechanism, as one of the technical solutions, the diffractive optical device is connected to the translational mechanism, the translational mechanism is arranged on the rotating mechanism, the rotation of the rotating mechanism drives the rotation of the translational mechanism, and further drives the rotation of the diffractive optical device; meanwhile, the two-dimensional horizontal movement of the diffractive optical device can be driven by the movement of the translational mechanism. As another technical solution, the diffractive optical device is connected to the rotating mechanism, the rotating mechanism is arranged on the translational mechanism, the horizontal movement of the translational mechanism drives the horizontal movement of the rotating mechanism, and further drives the horizontal movement of the diffractive optical device; meanwhile, the rotation of the diffractive optical device can be driven by the rotation of the rotating mechanism.

[0013] The mechanical movement subsystem further comprises an automatic focusing driving mechanism, which is used to drive the servo movement of the automatic focusing optical path.

[0014] The galvanometer driving device can be a swinging mechanism, which is used to drive the swinging of the galvanometer.

[0015] The control subsystem is electrically connected with the switch of the light source, the spatial light modulator, and the mechanical movement subsystem, and is used to coordinately control the time sequence operation of the switch of the light source, the image refreshing of the spatial light modulator, the rotation of the galvanometer, and the two-dimensional translational movement of the translational device. Thus, the printing of the diffractive field based on the diffusing speckle noise, the Gaussian distribution elimination, and the tunable diffractive structure of each diffractive pixel is realized.

[0016] The control subsystem can also coordinately control the automatic focusing optical path and / or the real-time monitoring control system, so as to ensure the stable operation of the system. The control subsystem is controlled by an industrial computer and control software.

[0017] The illumination optical subsystem further comprises a beam expander collimator, which comprises a beam expander and a collimator. The beam splitter is arranged between the light source and the beam expander collimator, or the beam splitter is arranged on the side of the beam expander collimator away from the light source.

[0018] The diffractive optical device is arranged between the beam expander and the collimator, or the diffractive optical device is arranged on the side of the beam expander collimator away from the light source.

[0019] The light source comprises a laser light source, a super radiation light source, or a light-emitting diode. The laser light source comprises a continuous laser light source or a pulsed laser light source. The pulsed laser light source comprises a nanosecond pulsed laser light source, a picosecond pulsed laser light source, or a femtosecond pulsed laser light source.

[0020] The sub-wavefront information is encoded into a data structure in units of diffraction pixels, the diffraction pixel unit contains amplitude and phase factors of the sub-wavefront information, and the phase factors include one or more of a first-order phase factor, a second-order phase factor, and a high-order phase factor; and the sub-wavefront information is decomposed from wavefront information of the diffraction field.

[0021] The data structure of the wavefront information of the diffraction field is decomposed and encoded by diffraction pixels, and the decomposition and encoding method encodes the amplitude and the phase factors into the amplitude or phase transmittance map of the corresponding pixel by using diffraction inversion calculation, wherein the phase factors include at least one of a first-order phase factor, a second-order phase factor, and a high-order phase factor.

[0022] The diffraction inversion calculation includes an optimization algorithm of a limited-band diffraction spot and a Gaussian-removed illumination light field, and the optimization algorithm includes holographic calculation, iteration, simulated annealing, or genetic algorithm.

[0023] The limited-band diffraction spot and the Gaussian-removed illumination light field in the application, wherein the illumination light field is realized by illuminating the diffraction optical device with a light beam, and the diffraction optical device and the light beam jointly act to simultaneously realize the limited-band diffraction spot and the Gaussian-removed uniform illumination on at least two planes of the near field or the far field of the diffraction optical device.

[0024] The diffraction optical device is obtained by optimization of an iterative algorithm, a simulated annealing algorithm, a genetic algorithm, or the like.

[0025] The application also includes a second technical solution, an optical output method of a diffraction field laser printing system, including: obtaining diffraction field information to be printed;

[0026] The wavefront information of the diffraction field to be printed is decomposed and encoded by diffraction pixels, wherein the diffraction pixels include diffraction structures of a limited-band diffraction spot and Gaussian-removed distribution;

[0027] The diffraction pixels are recorded on a diffraction field recording material by interference of object light and reference light of the diffraction field printing system, and the diffraction field is printed;

[0028] The object light is formed by a first illumination light field of a diffraction field printing system and an imaging light path of an imaging optical subsystem; the diffraction pixel forms a diffraction spot and a wave front information with a non-Gaussian distribution in the near field and the far field of the diffraction field; the wave front information of the diffraction pixel is modulated by refreshing the object light and / or transforming the reference light; the transformation of the reference light includes adjusting the intensity of the reference light and / or the direction of the reference light; the wave front information is decomposed into a plurality of sub-wave front information, and the sub-wave front information is encoded into a data structure in units of diffraction pixels; the diffraction pixel unit contains amplitude and phase factor information of the sub-wave front information, and the phase factor information includes at least one of a first phase factor, a second phase factor and a high-order phase factor.

[0029] The diffraction pixel is used to decompose and encode the wave front information of the diffraction field to be printed, including:

[0030] The amplitude and phase factor information is encoded into an amplitude and phase transmittance distribution map of the corresponding diffraction pixel by using a diffraction inversion calculation method, wherein the diffraction inversion calculation method includes an optimization algorithm under a limited-band diffraction spot and a non-Gaussian illumination light field, and the optimization algorithm includes holographic calculation, iteration, simulated annealing or genetic algorithm;

[0031] The amplitude and / or phase transmittance distribution map is input and refreshed into the object light path of the diffraction field laser printing system;

[0032] The object light reproduces the sub-wave front information by diffraction of the amplitude and / or phase transmittance distribution map.

[0033] The refreshing of the object light includes refreshing the amplitude and / or phase transmittance distribution map formed by the data structure encoding of the spatial light modulator in the object light path to realize modulation;

[0034] The adjustment of the intensity of the reference light includes adjusting the position of the diffraction optical device by panning or rotating the diffraction optical device.

[0035] The adjustment of the direction of the reference light includes adjusting the angle of the galvanometer mirror, or adjusting the angle of the galvanometer mirror and the position of the diffraction field recording material, or adjusting the angle of the galvanometer mirror and the position of the diffraction optical device, or adjusting the angle of the galvanometer mirror, the position of the diffraction field recording material and the position of the diffraction optical device.

[0036] The optical output method of the present application is an optical output method of a tunable diffraction field based on a diffraction structure with pixel-internal diffraction spot noise and non-Gaussian distribution, which at least utilizes one of the dynamic modulation characteristics of the limited-band diffraction spot, the non-Gaussian illumination light field, the high-speed refreshing spatial light modulator and the adjustable reference light.

[0037] The present application has the following advantages:

[0038] (1) The diffraction field output printing system of the present application, the large-format diffraction field formed can realize diffraction spot noise elimination and Gaussian distribution elimination in near field and far field, and the diffraction field has higher high signal-to-noise ratio and uniformity.

[0039] (2) The diffraction field output printing system of the present application, wherein the diffraction structure of the diffraction field can be independently tuned pixel by pixel, and an arbitrary complex multifunctional diffraction field can be obtained; the diffraction pixel unit of the present application can be spliced into a large size as needed, so that it can be used to form a large-format diffraction field. The large-format diffraction field of the present application refers to a diffraction field with an area greater than or equal to 40.6 cm x 30.5 cm. The area of the diffraction field formed by the present application is affected by the area of the platform carrying the photosensitive material, so the larger the area of the photosensitive material carried by the translation device, the larger the area of the diffraction field formed.

[0040] (3) The diffraction field laser printing system of the present application, the formed diffraction field has more modulation dimensions, and by switching, rotating and / or moving the diffractive optical device; refreshing the spatial light modulator; modulating the intensity and / or direction of the reference light, a high-dimensional diffraction field with complex functions can be formed. Moreover, the modulation dimensions of the diffraction field formed by the present application are independent of each other, and the modulation is more flexible. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is the forming process and effect diagram of the band-limited diffraction spot, Gaussian-eliminated illumination light field of an embodiment of the present application;

[0042] Figure 2 (a) is the light field intensity distribution diagram on the mid-plane (x1, y1); Figure 1 (b) is the phase distribution diagram of the diffractive optical device 4; Figure 2 (c) is the light field intensity distribution diagram on the near-field plane (x2, y2); Figure 2 (d) is the light field intensity distribution diagram on the far-field plane (x3, y3); Figure 1 Figure 2 Figure 1

[0043] Figure 3 (a) is the light field intensity distribution diagram on the plane (x1, y1) in the prior art; Figure 3 (b) is the phase distribution diagram of the diffractive optical device 4 in the prior art; Figure 3 (c) is the light field intensity distribution diagram on the near-field plane (x2, y2) in the prior art; Figure 3 (d) is the light field intensity distribution diagram on the far-field plane (x3, y3) in the prior art;

[0044] Figure 4 ​​​is a schematic diagram of an embodiment of the data structure of the diffraction field of the spherical wavefront information of the present application and its decomposition and coding;

[0045] Figure 5 is a schematic diagram of an embodiment of the data structure of the diffraction field of the planar wavefront information of the present application and its decomposition and coding;

[0046] Figure 6 is a schematic diagram of an embodiment of the data structure of the diffraction field of the complex wavefront information with high-order phase factors of the present application and its decomposition and coding;

[0047] Figure 7 is a schematic diagram of the cross-sectional structure of an embodiment of the diffraction field printing system of the present application;

[0048] Figure 8 is a schematic diagram of the cross-sectional structure of another embodiment of the diffraction field printing system of the present application;

[0049] Figure 9 is a schematic diagram of the top view structure of an embodiment of the diffraction field printing system of the present application;

[0050] Figure 10 is a schematic diagram of the top view structure of another embodiment of the diffraction field printing system of the present application;

[0051] Figure 11 is a schematic diagram of the top view structure of still another embodiment of the diffraction field printing system of the present application.

[0052] Wherein, 1, light source; 2, beam expander collimator; 3, illumination light beam; 4, diffractive optical device; 5, illumination light field; 6, light field distribution; 7, spatial light modulator; 8, Fourier transform lens group; 9, field stop; 10, mechanical frame structure; 11, half-transmission half-reflection mirror; 12, reflecting mirror; 13, galvanometer mirror; 14, lens; 15, lens; 16, translation device; 17, photosensitive material; 18, aperture stop; 19, collimating mirror; 20, beam expander mirror; 21, polarization beam splitter prism; 22, micro-imaging lens group; 23, image plane of the output surface of the Fourier transform lens; 24, dichroic mirror; 25, monitoring camera; 26, digital micromirror device display; 27, total reflection prism; 28, electric control box; 29, industrial computer; 30, servo focusing system; 40, reproduction illumination light beam; 50, diffractive structure; 50-1, diffractive pixel; 501, spherical wavefront; 502, planar wavefront; 503, complex wavefront; 500, sub-wavefront. DETAILED DESCRIPTION

[0053] The present application will be further described in detail below with reference to the accompanying drawings, so that those skilled in the art can implement the present application according to the description and the drawings.

[0054] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof. The terms “first” and “second” used herein are used only to distinguish elements and do not limit the elements.

[0055] Example 1

[0056] like Figure 1 As shown, in this embodiment, the diffractive optical device 4 is located at the coordinate plane (x1, y1). The near-field plane (x2, y2) of the diffractive optical device 4 is located at a distance Z from the coordinate plane (x1, y1). The far-field plane (x3, y3) of the diffractive optical device 4 is located at infinity from the near-field plane (x2, y2). Infinity is understood as infinity in optical distance, or a distance large enough to satisfy the Fraunhofer diffraction condition.

[0057] In this embodiment of the invention, the light source 1 is a laser. The laser emits laser light, which, after passing through the beam expander and collimator 2, forms an illumination beam 3. The illumination beam 3 is incident on the diffractive optical device 4, and the light field intensity distribution on the front surface of the diffractive optical device 4 is a Gaussian distribution. As the illumination beam continues to propagate forward, a band-limited, Gaussian-free illumination field 5 is formed on the near-field plane (x2, y2), which is the band-limited, Gaussian-free light field distribution. As the illumination beam continues to propagate forward, a band-limited, Gaussian-free light field distribution 6 is also formed on its far-field plane. The shape of the light spots on the near-field and far-field planes can be similar or different, and the area of ​​the light spots can be the same or different.

[0058] like Figure 2 As shown, (a) is Figure 1 (a) is the light field intensity distribution on the midplane (x1, y1); (b) is the phase distribution of the diffractive optical device 4; (c) is... Figure 1 The light field intensity distribution on the near-field plane (x2, y2); (d) is... Figure 1 The light field intensity distribution diagram on the mid-far field plane (x3, y3) shows that a band-limited, speckle-free, and Gaussian-free illumination light field is formed in both the near-field and far-field planes of the diffractive optical device 4. Therefore, the illumination technology of this invention constrains both the near and far fields, forming a band-limited, speckle-free, and Gaussian-free illumination light field in both the near-field and far-field planes of the diffractive optical device 4.

[0059] Existing illumination techniques only constrain the near-field plane; the far-field beam remains uncontrolled or still exhibits a Gaussian distribution. For example... Figure 3As shown, (a) is a light field intensity distribution diagram in the prior art on the plane (x1, y1); (b) is a phase distribution diagram of the prior art diffractive optical device 4; (c) is a light field intensity distribution diagram in the prior art on the near field plane (x2, y2); (d) is a light field intensity distribution diagram in the prior art on the far field plane (x3, y3); as Figure 3 As shown, there is non-uniformity and distortion in the far field of the diffractive field, such as brightness non-uniformity; this structure of the prior art will introduce non-uniformity and distortion in the far field of the diffractive field, such as brightness non-uniformity. The near field distribution of the prior art is seriously polluted by random speckle noise, which will seriously affect the quality of the diffractive field.

[0060] In comparison with the prior art, the illumination technology of the present application has constraints on both the near field and the far field, and forms a band-limited, speckle-free, Gaussian-removed illumination light field in the near field plane and the far field plane of the diffractive optical device 4. The band-limited, speckle-free, Gaussian-removed illumination light field formed by the present application completely solves the problems of non-uniformity and distortion in the far field, serious pollution of the near field distribution by random speckle noise, and low quality of the diffractive field.

[0061] Embodiment 2

[0062] As shown in Figure 4 The diffractive field in this embodiment is a converging quadratic spherical wave with a radius of Z1 formed by the diffractive structure 50 under the illumination condition of the reproduction illumination light beam 40, and the complex amplitude of the wave front on the plane (x4, y4) is:

[0063]

[0064] wherein the reproduction illumination light beam 40 is a light beam distribution formed by the diffractive field printing system on the diffractive field recording material.

[0065] The diffractive structure 50 is arranged and combined by a series of diffractive pixels 50-1, and the wave front information on the plane (x4, y4) is decomposed into a series of sub-wave fronts 500 according to the interval of the diffractive pixels 50-1, each sub-wave front 500 is a part of a spherical wave front 501, and all the sub-wave fronts 500 can be superimposed to form a complete spherical wave front 501. The sub-wave front 500 of each pixel is:

[0066]

[0067] wherein (px4, py4) is the center coordinate of each diffractive pixel 50-1, w x ,w yThese are the dimensions of the diffraction pixel in the x and y directions, respectively, and rect(x,y) is the aperture function in the field of information optics. The information of each wavefront 500 is encoded into the data structure corresponding to the diffraction pixel 50-1 through holographic calculation based on the illumination conditions in Example 1 (i.e., reproducing the illumination beam 40).

[0068] like Figure 5 As shown, the diffraction field in this embodiment is a plane wave with wave vector k formed by the diffraction structure 50 under the illumination conditions of the reconstructed illumination beam 40, and its complex amplitude on the plane (x4, y4) is:

[0069] A(x4,y4)exp[jk(x4cosα+x4cosβ)]

[0070] Where cosα and cosβ are the direction cosines of the plane wave. The diffraction structure 50 is composed of a series of diffraction pixels 50-1 arranged together. The wavefront information is decomposed into a series of sub-wavefronts 500 on the plane (x4, y4) according to the interval of the diffraction pixels 50-1. Each sub-wavefront 500 is part of the plane wavefront 502, and all the sub-wavefronts 500 can be superimposed to form a complete plane wavefront 502. The sub-wavefront 500 of each diffraction pixel is:

[0071]

[0072] Where (px4, py4) are the center coordinates of each diffraction pixel 50-1, w x ,w y These are the dimensions of the diffraction pixel in the x and y directions, respectively, where rect(x,y) is the aperture function in the field of information optics. The information of each sub-wavefront is encoded into the data structure corresponding to the diffraction pixel 50-1 through holographic calculation based on the illumination conditions in Example 1.

[0073] like Figure 6 As shown, the diffraction field in this embodiment is a complex wavefront 503 containing higher-order phases formed by the diffraction structure 50 under the illumination conditions of the reconstructed illumination beam 40. The complex amplitude of its wavefront on the plane (x4, y4) is:

[0074]

[0075] Where G(ξ, η) is the spectrum of the complex wavefront 503. λ is wavelength, cos a, cos β are direction cosines. The diffraction structure 50 is composed of a series of diffraction pixels 50-1, the wavefront information is decomposed into a series of sub-wavefronts 500 in the plane (x4, y4) according to the interval of the diffraction pixels 50-1, each sub-wavefront 500 is a part of the complex wavefront 503, and all the sub-wavefronts 500 can be superimposed to form a complete complex wavefront 503. The sub-wavefront 500 of each diffraction pixel is:

[0076]

[0077] where (px4, py4) is the center coordinate of each diffraction pixel 50-1, w x ,w y are the sizes of the diffraction pixel x, y direction respectively, and rect(x, y) is a rectangular aperture function in the field of information optics. The information of each sub-wavefront is encoded to form the data structure corresponding to the diffraction pixel 50-1 by an iterative algorithm based on the illumination condition in embodiment 1.

[0078] Embodiment 3

[0079] As Figure 7 shown, the embodiment of the present application provides a diffraction field laser printing system, which comprises a light source 1, an illumination optical subsystem, an imaging optical subsystem, a reference light subsystem, a mechanical motion subsystem and a control subsystem.

[0080] The illumination optical subsystem comprises a beam splitter, light emitted by the light source 1 enters the illumination optical subsystem and is split by the beam splitter into a first illumination light field and a second illumination light field; the imaging optical subsystem comprises a diffractive optical device 4, a spatial light modulator 7 and a Fourier transform lens, the spatial light modulator 7 is located at the input face of the Fourier transform lens, the spatial light modulator 7 is used for modulating the data structure corresponding to the sub-wavefront information and forming the sub-wavefront information of the diffraction field on the output face of the Fourier transform lens, wherein the first illumination light field illuminates the imaging optical subsystem, so that the first illumination light field sequentially passes through the diffractive optical device 4, the spatial light modulator 7 and the Fourier transform lens, and a limited-band diffraction spot and a Gaussian-removed light field distribution are simultaneously formed on the input face and the output face of the Fourier transform lens; the reference light subsystem comprises a galvanometer 13 and a relay lens group, the second illumination light field enters the reference light subsystem, so that the second illumination light field sequentially passes through the galvanometer 13 and the relay lens group, and a reference light field is formed on the output face of the relay lens group; wherein the light spot formed by the reference light field coincides with the output face of the Fourier transform lens or the image face of the output face; the mechanical motion subsystem comprises a galvanometer driving device and a translation device 16, the galvanometer driving device is used for driving the galvanometer to rotate in two dimensions; the translation device 16 is used for driving the diffraction field recording material 17 to move in translation, wherein the photosensitive face of the diffraction field recording material 17 coincides with the output face of the Fourier transform lens or the image face of the output face; the control subsystem is used for controlling the image refreshing of the spatial light modulator 7 and the motion of the mechanical motion subsystem.

[0081] In the embodiment of the application, the control subsystem is electrically connected with the switch of the light source 1, the spatial light modulator 7 and the mechanical motion subsystem, and is used for coordinately controlling the switch of the light source 1, the image refreshing of the spatial light modulator 7, the rotation of the galvanometer 13 and the two-dimensional translation motion of the translation device 16 to operate in time sequence, so as to control the working or stopping of the light source 1, the image refreshing of the spatial light modulator 7, the angle change of the reflected light beam of the galvanometer 13 and the position of the diffraction field recording material 17.

[0082] In the embodiment of the application, the beam splitter is a half-transmission half-reflection mirror 11, and in the embodiment of the application, the illumination optical subsystem further comprises an expander collimator 2, and the half-transmission half-reflection mirror 11 is arranged between the expander collimator 2 and the diffractive optical device 4.

[0083] In the embodiment of the application, the relay lens group is composed of a lens 14 and a lens 15, and in other embodiments, the relay lens group can also be composed of multiple lenses.

[0084] Specifically, in the embodiment of the application, the light source 1 comprises a laser light source, and more specifically, the laser light source in the embodiment of the application is a laser. In other embodiments, the light source can also be a super radiation light source or a light-emitting diode light source.

[0085] Specifically, in the embodiment of the present application, the imaging optical subsystem comprises a diffractive optical device 4, a spatial light modulator 7, a Fourier transform lens group 8 and a field stop 9; in the embodiment of the present application, the spatial light modulator 7 is an amplitude type spatial light modulator. In the embodiment of the present application, the Fourier transform lens is a Fourier transform lens group 8, and in other embodiments, it can also be a Fourier transform lens.

[0086] In the embodiment of the present application, the translation device 16 is a two-dimensional translation stage, and the diffractive field recording material 17 is arranged on the two-dimensional translation stage, and the two-dimensional translation stage adjusts the reciprocating movement of the diffractive field recording material 17 along the optical axis direction. In the embodiment of the present application, the two-dimensional translation stage comprises a two-dimensional precision translation stage, and in the embodiment of the present application, the size of the two-dimensional translation stage affects the size of the diffractive field recording material 17 carried by the two-dimensional translation stage. By increasing the carrying area of the two-dimensional translation stage, the area of the diffractive field recording material 17 can be increased, and thus the area of the formed diffractive field can be increased. The diffractive field recording material 17 in the embodiment of the present application is a photosensitive material.

[0087] In the embodiment of the present application, the galvanometer driving device comprises a swing mechanism (not marked in the figure), that is, the galvanometer 13 can be driven to swing or rotate along one direction.

[0088] In the embodiment of the present application, the reference light subsystem further comprises an aperture stop 18, and the aperture stop 18 is used to control the shape and size of the light spot formed by the reference light.

[0089] In the embodiment of the present application, a mirror 12 is further included, and the mirror 12 is used to change the path of the light beam.

[0090] In the embodiment of the present application, the diffractive field laser printing system further comprises a mechanical frame structure 10, and the mechanical frame structure 10 of the present application forms a containing cavity inside, and the containing cavity contains the mirror 12, the aperture stop 18 and the galvanometer 13. Two through holes are arranged on the surface of the mechanical frame structure 10, and the through holes enable the light beam to pass through. In the embodiment of the present application, the surface of the mechanical frame structure 10 can be used to support the light source 1, the imaging optical subsystem, part of the reference light subsystem and part of the mechanical motion subsystem. The embodiment of the present application is only used to illustrate the mechanical frame structure 10, and does not limit the structure and purpose of the mechanical frame structure 10.

[0091] Specifically, in the embodiment of the present application, the working principle of the diffractive field laser printing system comprises:

[0092] S1: The light emitted by the light source 1 reaches the illumination optical subsystem and is split by the beam splitter to form a first illumination light field and a second illumination light field.

[0093] Specifically, in the embodiment of the present application, the light source emits light, which forms an illumination light beam 3 after passing through the beam expander collimator 2. The illumination light beam 3 is divided into two beams by the half-transmission half-reflection mirror 11, one of which is transmitted light, and the other is reflected light. The transmitted light is the first illumination light field, and the reflected light is the second illumination light field.

[0094] S2: The first illumination light field illuminates the imaging optical subsystem. The first illumination light field sequentially passes through the diffractive optical device, the spatial light modulator, and the Fourier transform lens, and simultaneously forms a limited-band annihilation spot and a de-Gaussian light field distribution on the input face and the output face of the Fourier transform lens.

[0095] The transmitted light is incident on the diffractive optical device 4. After the light beam passes through the diffractive optical device 4, a limited-band annihilation spot and a de-Gaussian illumination light field 5 are formed at a position with a distance Z from the diffractive optical device 4. The illumination light field 5 illuminates the spatial light modulator 7, which displays the information coding of the wavelet front in the embodiment 2 to form a data structure corresponding to the diffractive pixel. The spatial light modulator 7 is located on the input face of the Fourier transform lens group 8. After the light passes through the spatial light modulator 7, an annihilation spot noise and a de-Gaussian distributed wavelet front are formed on the output face of the Fourier transform lens group 8, that is, a light field 6 with an annihilation spot noise and a de-Gaussian distribution is formed. The field stop 9 is located on the output face of the Fourier transform lens group 8, and the output face coincides with the plane where the diffractive field recording material 17 is located. In the embodiment of the present application, the wavelet front passes through the field stop 9 and forms a first light spot on the surface of the diffractive field recording material 17.

[0096] In the embodiment of the present application, the first illumination light field illuminates the imaging optical subsystem, that is, the first illumination light field sequentially passes through the diffractive optical device, the spatial light modulator, and the Fourier transform lens, and forms an object light path, that is, an object light that irradiates the diffractive field recording material 17.

[0097] S3: The second illumination light field illuminates the reference light subsystem to form an adjustable reference light. The output face of the Fourier transform lens or the image face of the output face coincides with the illumination face of the reference light. The interference between the reference light and the object light forms a diffractive field, wherein the object light is formed by the first illumination light field imaging optical subsystem of the diffractive field printing system.

[0098] In the embodiment, the reflected light of the half-transmission half-reflection mirror 11 passes through the aperture stop 18 after being reflected by the mirror 12, and then is incident on the two-dimensional galvanometer. After the light is reflected by the two-dimensional galvanometer, it enters the relay lens group composed of the lens 14 and the lens 15. After the light passes through the relay lens group, a second light spot is formed on the surface of the diffractive field recording material 17. The second light spot coincides with the first light spot of the wavelet front formed by the transmitted light of the half-transmission half-reflection mirror 11 on the surface of the diffractive field recording material 17. A diffractive field is formed on the diffractive field recording material 17 by the interference of the two light beams.

[0099] In the embodiment of the present application, the second illumination light field illuminates the reference light sub-system to form a reference light path.

[0100] In the embodiment, the adjustment of the diffraction field can be achieved by any one of the following two ways or both of them, which are as follows: (1) refreshing the data structure corresponding to the sub-pixel of the amplitude type spatial light modulator; (2) changing the angle of the reflected light beam of the two-dimensional galvanometer.

[0101] The control sub-system of the embodiment coordinates the switching of the laser (not shown in the figure), the refreshing of the spatial light modulator 7, the deflection of the two-dimensional galvanometer, and the movement of the translation device 16, so as to realize the optical output of the diffraction field of the pixel-by-pixel tunable diffraction structure based on the in-pixel dissipation speckle noise and the Gaussian distribution.

[0102] In the embodiment of the present application, the diffraction field optical output method is also included, which uses the diffraction field printing system described above, and includes the following steps.

[0103] S10: obtaining the diffraction field information to be printed.

[0104] In the embodiment of the present application, the information of the diffraction field to be printed can be picture information.

[0105] S20: using the diffraction pixel decomposition and encoding the wavefront information of the diffraction field to be printed, wherein the diffraction pixel includes the limited-band dissipation speckle and the Gaussian distribution diffraction structure.

[0106] In the embodiment of the present application, the amplitude and phase factor information is encoded into the amplitude and phase transmittance distribution map of the corresponding diffraction pixel by using the diffraction inversion calculation method, wherein the diffraction inversion calculation method includes the optimization algorithm under the limited-band dissipation speckle and the Gaussian distribution illumination light field, and the optimization algorithm includes holographic calculation, iteration, simulated annealing or genetic algorithm, and the embodiment of the present application is not limited to the above optimization algorithm; the amplitude and / or phase transmittance distribution map is input and refreshed into the object light path of the diffraction field laser printing system; the object light reproduces the sub-wavefront information by diffraction on the amplitude and / or phase transmittance distribution map.

[0107] S30: the diffraction pixels are recorded on the diffraction field recording material 17 by the interference of the object light and the reference light of the diffraction field printing system one by one to print the diffraction field; wherein the object light is formed by the object light path composed of the first illumination light field illumination imaging optical sub-system of the diffraction field printing system; the diffraction pixel forms the dissipation speckle and the Gaussian distribution wavefront information in the near field and the far field of its diffraction field at the same time; the wavefront information of the diffraction pixel is modulated by the refreshing of the object light and / or the transformation of the reference light; the wavefront information is decomposed into several sub-wavefront information, the sub-wavefront information is encoded to form a data structure with the diffraction pixel as a unit, the diffraction pixel unit contains the amplitude and phase factor information of the sub-wavefront information, and the phase factor information includes at least one of the first phase factor, the second phase factor and the high-order phase factor.

[0108] In the embodiment of the present application, the refreshing of the object light comprises refreshing the amplitude and / or phase transmittance distribution diagram of the data structure corresponding to the spatial light modulator 7 on the light path of the object light to realize the modulation.

[0109] The adjustment of the direction of the reference light comprises: adjusting the angle of the galvanometer; or, adjusting the angle of the galvanometer and adjusting the position of the diffractive field recording material, or, adjusting the angle of the galvanometer and adjusting the position of the diffractive optical device, or, adjusting the angle of the galvanometer, adjusting the position of the diffractive field recording material and adjusting the position of the diffractive optical device.

[0110] Embodiment 4

[0111] As shown in Figure 8 The embodiment of the present application provides a diffractive field laser printing system, which comprises a light source 1, an illumination optical subsystem, an imaging optical subsystem, a reference light subsystem, a mechanical motion subsystem and a control subsystem.

[0112] The illumination optical subsystem comprises a beam splitter, and the light emitted by the light source 1 enters the illumination optical subsystem and is split by the beam splitter into a first illumination light field and a second illumination light field;

[0113] The imaging optical subsystem comprises a diffractive optical device 4, a spatial light modulator 7 and a Fourier transform lens, the spatial light modulator 7 is located at the input face of the Fourier transform lens, the spatial light modulator 7 is used for modulating the data structure corresponding to the sub-wavefront information and forming the sub-wavefront information of the diffractive field on the output face of the Fourier transform lens, wherein the first illumination light field illuminates the imaging optical subsystem, so that the first illumination light field passes through the diffractive optical device 4, the spatial light modulator 7 and the Fourier transform lens in turn, and a limited-band diffraction spot and a Gaussian-removed light field distribution are formed on the input face and the output face of the Fourier transform lens at the same time;

[0114] The reference light subsystem comprises a galvanometer 13 and a relay lens group, the second illumination light field enters the reference light subsystem, so that the second illumination light field passes through the galvanometer 13 and the relay lens group in turn, and a reference light field is formed on the output face of the relay lens group; wherein the light spot formed by the reference light field coincides with the output face of the Fourier transform lens or the image face of the output face;

[0115] The mechanical motion subsystem comprises a galvanometer driving device and a translation device 16, the galvanometer driving device is used for driving the galvanometer to rotate in two dimensions; the translation device 16 is used for driving the diffractive field recording material 17 to move in translation, wherein the photosensitive surface of the diffractive field recording material 17 coincides with the output face of the Fourier transform lens or the image face of the output face;

[0116] The control subsystem is used for controlling the image refreshing of the spatial light modulator 7 and controlling the motion of the mechanical motion subsystem.

[0117] In the embodiment of the present application, the control subsystem is electrically connected with the switch of the light source 1, the spatial light modulator 7 and the mechanical motion subsystem, and is used for coordinating the control of the switch of the light source, the image refreshing of the spatial light modulator 7, the rotation of the galvanometer 13 and the two-dimensional translation motion of the translation device 16 according to the time sequence.

[0118] In the embodiment of the present application, the beam splitter is a half-transmission half-reflection mirror 11, and in the embodiment of the present application, the illumination optical subsystem further comprises a beam expander collimator 2, the beam expander collimator 2 comprises a beam expander mirror 20 and a collimator mirror 19, the diffractive optical device 4 is arranged between the beam expander mirror 20 and the collimator mirror 19, and the half-transmission half-reflection mirror 11 is located between the beam expander mirror 20 and the light source 1.

[0119] Specifically, in the embodiment of the present application, the mechanical motion subsystem further comprises a translation mechanism (not shown in the figure); the translation mechanism is used for driving the diffractive optical device 4 to move two-dimensionally horizontally in space, the diffractive optical device 4 is installed on the translation mechanism, and the translation mechanism moves reciprocally along the optical axis direction to drive the diffractive optical device 4 to move. In the embodiment of the present application, the galvanometer driving device is a swing mechanism (not shown in the figure), and the swing mechanism can drive the galvanometer 13 to swing. In the embodiment of the present application, the relay lens group is composed of the lens 14 and the lens 15, and in other embodiments, the relay lens group can also be composed of multiple lenses. In the embodiment of the present application, the galvanometer 13 is a two-dimensional galvanometer. In other embodiments, the mechanical motion subsystem further comprises a rotation mechanism (not shown in the figure), and the rotation mechanism is used for driving the diffractive optical device 4 to move rotationally in space. In other embodiments, the translation mechanism can not be arranged, the rotation mechanism is arranged, the diffractive optical device 4 is arranged on the rotation mechanism, and the rotation mechanism drives the diffractive optical device 4 to rotate.

[0120] In the embodiment of the present application, the translation device 16 is a two-dimensional translation stage, the diffractive field recording material 17 is arranged on the two-dimensional translation stage, and the two-dimensional translation stage adjusts the diffractive field recording material 17 to move reciprocally along the optical axis direction. In the embodiment of the present application, the two-dimensional translation stage comprises a two-dimensional precision translation stage, and in the embodiment of the present application, the size of the two-dimensional translation stage affects the size of the diffractive field recording material 17, the carrying area of the two-dimensional translation stage can be increased by increasing the size of the two-dimensional translation stage, the area of the diffractive field recording material 17 can be increased, and then the area of the formed diffractive field can be increased. The diffractive field recording material 17 in the embodiment of the present application is a photosensitive material.

[0121] Specifically, in the embodiment of the present application, the light source 1 comprises a laser light source, and more specifically, the laser light source in the embodiment of the present application is a laser. In the embodiment of the present application, the laser light source is a continuous laser light source, and in other embodiments, the laser light source can also be a pulsed laser light source, the pulsed laser light source comprising a nanosecond pulsed laser light source, a picosecond pulsed laser light source or a femtosecond pulsed laser light source.

[0122] Specifically, in the embodiment of the present application, the imaging optical subsystem comprises a spatial light modulator 7, a Fourier transform lens group 8 and a field stop 9. In the embodiment of the present application, a Fourier transform lens group 8 is used, and in other embodiments, a Fourier transform lens can also be used. In the embodiment of the present application, the spatial light modulator 7 is a phase-type spatial light modulator. The field stop 9 is located on the output surface of the Fourier transform lens group 8.

[0123] The embodiment of the present application also comprises a mechanical frame structure 10, and the mirror 12, the aperture stop 18 and the galvanometer 13 are located in the mechanical frame structure 10.

[0124] In the embodiment of the present application, the diffractive field laser printing system also comprises a mirror 12, which is used to reflect the light reflected by the semi-transparent mirror 11 to the aperture stop 18.

[0125] In the embodiment of the present application, the control subsystem is electrically connected with the switch of the light source 1, the spatial light modulator 7 and the mechanical motion subsystem, and the control subsystem is used to coordinately control the switch of the light source 1, the image refreshing of the spatial light modulator 7, the rotation of the galvanometer 13, the two-dimensional translational motion of the translation device 16 and the two-dimensional translational motion of the translation mechanism to operate in time sequence. In order to control the recording of a complex high-dimensional diffractive field with high signal-to-noise ratio and high uniformity on the diffractive field recording material 17.

[0126] Specifically, in the embodiment of the present application, the working principle of the diffractive field laser printing system comprises:

[0127] S1: the light emitted by the light source 1 reaches the illumination optical subsystem and is split by the beam splitter to form a first illumination light field and a second illumination light field.

[0128] Specifically, in the embodiment of the present application, the laser emits laser light which is split into two beams of light by the semi-transparent mirror 11, one of which is transmitted light and the other of which is reflected light, the transmitted light being the first illumination light field and the reflected light being the second illumination light field.

[0129] S2: the first illumination light field illuminates the imaging optical subsystem, and the first illumination light field sequentially passes through the diffractive optical device 4, the spatial light modulator 7 and the Fourier transform lens to simultaneously form a limited-band annihilation spot and a Gaussian-removed light field distribution on the input surface and the output surface of the Fourier transform lens.

[0130] In the embodiment of the present application, the transmitted light enters the expansion collimator 2, and the light beam forms an illumination light beam 3 after passing through the diffractive optical device 4 and the collimating mirror 19, and the illumination light beam 3 forms a limited-band annihilation spot and a Gaussian-removed illumination light field 5 at a position with a distance Z from the collimating mirror 19.

[0131] In the embodiment of the present application, the illumination light field 5 illuminates the phase type spatial light modulator, and the phase type spatial light modulator displays the information coding of the wavelet front of the embodiment 2 to form the data structure corresponding to the sub-pixel. The spatial light modulator 7 is located on the input surface of the Fourier transform lens group 8, and the light passes through the spatial light modulator 7 to form the wavelet front with diffraction spot noise eliminated and Gaussian distribution removed on the output surface of the Fourier transform lens group 8, that is, the light field 6 with diffraction spot noise eliminated and Gaussian distribution removed. The field stop 9 is located on the output surface of the Fourier transform lens group 8, and the output surface is coincident with the plane where the photosensitive material is located, and the photosensitive material is located on the translation device 16. The wavelet front passes through the field stop 9 and forms the first light spot on the surface of the diffraction field recording material 17.

[0132] In the embodiment of the present application, the first illumination light field illuminates the imaging optical system, that is, the first illumination light field sequentially passes through the diffractive optical device 4, the spatial light modulator 7 and the Fourier transform lens to form the object light path and form the object light irradiated to the diffraction field recording material 17.

[0133] S3: The second illumination light field illuminates the reference optical system to form the adjustable reference light, and the output surface of the Fourier transform lens or the image surface of the output surface is coincident with the illumination surface of the reference light; the interference between the reference light and the object light forms the diffraction field, wherein the object light is formed by the first illumination light field of the diffraction field printing system.

[0134] In the embodiment of the present application, the reflected light passes through the aperture stop 18 after passing through the mirror 12, and then is incident on the two-dimensional galvanometer, the light is reflected by the two-dimensional galvanometer and enters the relay lens group composed of the lens 14 and the lens 15, the relay lens group forms the second light spot on the surface of the photosensitive material, and the second light spot is coincident with the first light spot of the wavelet front on the surface of the photosensitive material. The diffraction field is formed on the photosensitive material by the interference of the two light beams.

[0135] In the embodiment of the present application, the adjustment of the diffraction field can be realized by any one of the following three ways, or any two combinations, or three simultaneous actions, and the three ways are as follows: (1) the spatial light modulator 7 refreshes the data structure corresponding to the sub-pixel; (2) the galvanometer 13 changes the angle of the reflected light beam; (3) the diffractive optical device 4 moves along the optical axis.

[0136] In the embodiment of the present application, the control subsystem coordinates the control of the switching of the laser, the refreshing of the spatial light modulator 7, the axial movement of the translation device 16 and the translation mechanism, controls the movement of the diffraction field recording material 17 and the axial movement of the diffractive optical device 4, controls the deflection of the two-dimensional galvanometer by controlling the working or stopping of the galvanometer driving device, so as to realize the optical output of the diffraction field based on the pixel-in diffraction spot noise eliminated and Gaussian distribution removed diffraction structure which is tunable pixel by pixel.

[0137] The embodiment of the present application also includes a diffraction field optical output method, which adopts the diffraction field printing system, and includes the following steps:

[0138] S10: obtaining diffraction field information to be printed.

[0139] In the embodiment of the present application, the information of the diffraction field to be printed can be picture information.

[0140] S20: decomposing and encoding the wavefront information of the diffraction field to be printed by using a diffraction pixel, wherein the diffraction pixel includes a limited-band speckle and a Gaussian-distribution-free diffraction structure.

[0141] In the embodiment of the present application, the amplitude and phase factor information is encoded into an amplitude and phase transmittance distribution map of the corresponding diffraction pixel by using a diffraction inversion calculation method, wherein the diffraction inversion calculation method includes an optimization algorithm under a limited-band speckle and a Gaussian-distribution-free illumination light field, and the optimization algorithm includes holographic calculation, iteration, simulated annealing or genetic algorithm; the amplitude and / or phase transmittance distribution map is input and refreshed into an object light path of the diffraction field laser printing system; and the object light reproduces the sub-wavefront information by diffraction of the amplitude and / or phase transmittance distribution map.

[0142] S30: the diffraction pixels are recorded on the diffraction field recording material 17 by interference of the object light and the reference light of the diffraction field printing system one by one to print the diffraction field, wherein the object light is formed by the object light path composed of the first illumination light field imaging optical subsystem of the diffraction field printing system; the diffraction pixel forms the wavefront information of the speckle and the Gaussian-distribution-free diffraction field at the same time; the wavefront information of the diffraction pixel is modulated by refreshing the object light and / or transforming the reference light; the transformation of the reference light includes adjusting the intensity of the reference light and / or the direction of the reference light; the wavefront information is decomposed into a plurality of sub-wavefront information, the sub-wavefront information is encoded into a data structure with the diffraction pixel as a unit, the diffraction pixel unit contains the amplitude and phase factor information of the sub-wavefront information, and the phase factor information includes at least one of a first phase factor, a second phase factor and a high-order phase factor.

[0143] In the embodiment of the present application, the refreshing of the object light includes refreshing the amplitude and / or phase transmittance distribution map formed by the data structure encoding of the spatial light modulator on the object light path to realize the modulation.

[0144] The adjustment of the intensity of the reference light includes: moving the diffractive optical device to adjust the position of the diffractive optical device. In other embodiments, the position of the diffractive optical device can also be adjusted by rotating the diffractive optical device, or rotating and moving the diffractive optical device at the same time.

[0145] The direction of the reference light can be adjusted in four ways: (1) modulating the angle of the galvanometer. (2) modulating the angle of the galvanometer and adjusting the position of the diffraction field recording material. (3) modulating the angle of the galvanometer and adjusting the position of the diffraction optical device. (4) modulating the angle of the galvanometer, adjusting the position of the diffraction field recording material, and adjusting the position of the diffraction optical device.

[0146] Example 5

[0147] like Figure 9 As shown in the embodiment of the present invention, a diffraction field laser printing system includes a light source 1, an illumination optical subsystem, an imaging optical subsystem, a reference photonics system, a mechanical motion subsystem, and a control subsystem.

[0148] The illumination optical subsystem includes a beam splitter. Light emitted from light source 1 enters the illumination optical subsystem and is split into a first illumination light field and a second illumination light field by the beam splitter. The imaging optical subsystem includes a diffractive optical device 4, a spatial light modulator 7, and a Fourier transform lens. The spatial light modulator 7 is located at the input surface of the Fourier transform lens. The spatial light modulator 7 is used to modulate the data structure corresponding to the sub-wavefront information and form the sub-wavefront information of the diffractive field on the output surface of the Fourier transform lens. The first illumination light field illuminates the imaging optical subsystem, so that the first illumination light field passes sequentially through the diffractive optical device 4, the spatial light modulator 7, and the Fourier transform lens, simultaneously forming a band-limited speckle extinguishing and Gaussian-reduced light field distribution on both the input and output surfaces of the Fourier transform lens. The reference photonic system includes a galvanometer 13 and a relay lens group. The second illumination light field enters the reference photonic system, causing the second illumination light field to pass sequentially through the galvanometer 13 and the relay lens group, forming a reference light field on the output surface of the relay lens group. The light spot formed by the reference light field coincides with the output surface or the image plane 23 of the Fourier transform lens. The mechanical motion subsystem includes a galvanometer drive device and a translation device. The galvanometer drive device is used to drive the galvanometer to perform two-dimensional rotation. The translation device is used to drive the diffraction field recording material 17 to perform translational motion. The photosensitive surface of the diffraction field recording material 17 coincides with the output surface or the image plane of the Fourier transform lens. The control subsystem is used to control the image refresh of the spatial light modulator 7 and to control the motion of the mechanical motion subsystem.

[0149] Specifically, in this embodiment of the invention, the beam splitter is a semi-transparent and semi-reflective mirror 11. In this embodiment of the invention, the illumination optical subsystem also includes a beam expander and collimator 2, which includes a beam expander 20 and a collimator 19. The diffractive optical device 4 is disposed between the beam expander 20 and the collimator 19, and the semi-transparent and semi-reflective mirror 11 is disposed between the light source 1 and the beam expander and collimator 2.

[0150] In the embodiment of the present application, the translation device 16 is a two-dimensional translation table, the diffraction field recording material 17 is arranged on the two-dimensional translation table, and the two-dimensional translation table adjusts the reciprocating movement of the diffraction field recording material 17 along the optical axis direction. In the embodiment of the present application, the two-dimensional translation table includes a two-dimensional precision translation table. In the embodiment of the present application, the size of the two-dimensional translation table affects the size of the diffraction field recording material 17. By increasing the bearing area of the two-dimensional translation table, the area of the diffraction field recording material 17 can be increased, and the area of the formed diffraction field can be increased. The diffraction field recording material 17 in the embodiment of the present application is a photosensitive material.

[0151] In the embodiment of the present application, the galvanometer driving device includes a swing mechanism (not marked in the figure), that is, the galvanometer 13 can be driven to swing reciprocally in one direction.

[0152] Specifically, in the embodiment of the present application, the mechanical movement subsystem further includes a translation mechanism (not marked in the figure), the translation mechanism is connected with the diffractive optical device 4, and the translation mechanism is used to drive the diffractive optical device 4 to make a translation movement in space. In other embodiments, the mechanical movement subsystem includes a rotation mechanism, the diffractive optical device 4 is arranged on the rotation mechanism, and the rotation mechanism is used to drive the diffractive optical device 4 to make a rotation movement in space. Or, when the mechanical movement subsystem simultaneously includes a translation mechanism and a rotation mechanism, the diffractive optical device is connected with the translation mechanism, the translation mechanism is arranged on the rotation mechanism, the rotation mechanism is used to drive the translation mechanism to rotate, and the translation mechanism is used to drive the diffractive optical device to rotate; at the same time, the two-dimensional horizontal movement of the diffractive optical device can be driven by the movement of the translation mechanism. Or, the diffractive optical device is connected with the rotation mechanism, the rotation mechanism is arranged on the translation mechanism, the horizontal movement of the rotation mechanism is driven by the horizontal movement of the translation mechanism, and the horizontal movement of the diffractive optical device is driven by the horizontal movement of the rotation mechanism; at the same time, the rotation of the diffractive optical device can be driven by the rotation of the rotation mechanism.

[0153] In the embodiment of the present application, the relay lens group is composed of the lens 14 and the lens 15, and in other embodiments, the relay lens group can also be composed of multiple lenses. In the embodiment of the present application, the galvanometer 13 is a two-dimensional galvanometer.

[0154] Specifically, in the embodiment of the present application, the light source 1 includes a laser light source, and more specifically, the laser light source in the embodiment of the present application is a laser.

[0155] Specifically, in the embodiment of the present application, the imaging optical subsystem includes a spatial light modulator 7, a polarization beam splitter prism 21, a Fourier transform lens group 8, a micro-imaging lens group 22 and a field stop 9. In the embodiment of the present application, a Fourier transform lens group 8 is used, and in other embodiments, a Fourier transform lens can also be used. In the embodiment of the present application, the spatial light modulator 7 is a phase-type spatial light modulator 7. In the embodiment of the present application, the field stop 9 is located on the output surface of the Fourier transform lens group 8, and the output surface coincides with the plane on which the diffraction field recording material 17 is located through the image formed by the mirror 12 and the micro-imaging lens group 22.

[0156] In the embodiment of the present application, the control subsystem is electrically connected with the switch of the light source 1, the spatial light modulator 7 and the mechanical motion subsystem, and the control subsystem is used to coordinate the control of the switch of the light source 1, the image refreshing of the spatial light modulator 7, the rotation of the galvanometer 13, the two-dimensional translation motion operation of the translation device 16 and the translation mechanism. In order to coordinate the control of the switch of the light source 1, the image refreshing of the spatial light modulator 7, the movement of the diffractive optical device 4, the movement of the diffraction field recording material 17 and the swing of the galvanometer 13.

[0157] In the embodiment of the present application, the diffractive field laser printing system further includes a mirror 12, and the mirror 12 is used to change the beam path in the embodiment of the present application.

[0158] Specifically, in the embodiment of the present application, the optical output method of the diffractive field laser printing system includes:

[0159] S1: The light emitted by the light source 1 reaches the illumination optical subsystem and is split by the beam splitter to form a first illumination light field and a second illumination light field.

[0160] Specifically, in the embodiment of the present application, the laser emits laser light which is split into two beams of light by the semi-transparent mirror 11, one transmitted light and one reflected light. Among them, the transmitted light is the first illumination light field, and the reflected light is the second illumination light field.

[0161] S2: The first illumination light field illuminates the imaging optical subsystem, and the first illumination light field sequentially passes through the diffractive optical device 4, the spatial light modulator 7 and the Fourier transform lens, and simultaneously forms a band-limited diffraction spot and a Gaussian-removed light field distribution on the input surface and the output surface of the Fourier transform lens.

[0162] In the embodiment of the present application, the transmitted light continues to enter the beam expander 20 of the beam expander collimator 2 of the illumination optical subsystem, and the light beam forms the illumination light beam 3 after passing through the diffractive optical device 4 and the collimating mirror 19. The illumination light beam 3 is reflected by the mirror 12, and then reflected by the polarization beam splitter prism 21 to form the limited-band annular spot, the de-Gaussian illumination light field 5 at the plane where the spatial light modulator 7 is located. The illumination light field 5 illuminates the phase-type spatial light modulator, and the phase-type spatial light modulator displays the information coding of the wavelet front in the embodiment 2 to form the data structure corresponding to the sub-pixel. The phase-type spatial light modulator is located on the input surface of the Fourier transform lens group 8, and the light passes through the phase-type spatial light modulator to form the annular spot noise, the de-Gaussian distributed wavelet front on the output surface of the Fourier transform lens group 8, that is, to form the annular spot noise, the de-Gaussian distributed light field 6. The field stop 9 is located on the output surface of the Fourier transform lens group 8, and the output surface coincides with the plane where the diffractive field recording material 17 is located through the image formed by the mirror 12 and the micro-imaging lens group 22, and the diffractive field recording material 17 is located on the translation device 16. The wavelet front passes through the field stop 9, the mirror 12 and the micro-imaging lens group 22, and forms the first light spot on the surface of the diffractive field recording material 17.

[0163] S3: The second illumination light field illuminates the reference light subsystem to form an adjustable reference light, and the output surface of the Fourier transform lens or the image surface 23 coincides with the illumination surface of the reference light; and the interference between the reference light and the object light forms a diffractive field, wherein the object light is formed by the first illumination light field illumination optical subsystem of the diffractive field printing system.

[0164] In the embodiment, the reflected light of the half-transmission half-reflection mirror 11 passes through the aperture stop 18 after being reflected by the mirror 12, and then enters the two-dimensional galvanometer. The light passes through the two-dimensional galvanometer to enter the relay lens group composed of the lens 14 and the lens 15, and the relay lens group forms the second light spot on the surface of the diffractive field recording material 17, and the second light spot coincides with the first light spot. The interference between the two light beams forms the diffractive structure on the diffractive field recording material 17.

[0165] In the embodiment, the adjustment of the diffractive field can be realized by any one of the following three ways, or any combination of two, or three ways acting simultaneously, and the three ways are as follows: (1) the spatial light modulator 7 refreshes the data structure corresponding to the sub-pixel; (2) the two-dimensional galvanometer changes the angle of the reflected light beam; (3) the diffractive optical device 4 moves axially along the optical axis.

[0166] In the embodiment of the present application, the control subsystem coordinates the switching of the laser, the refreshing of the spatial light modulator 7, the axial movement of the translation device 16 and the translation mechanism, to control the movement of the diffractive field recording material 17 and the axial movement of the diffractive optical device 4, controls the operation or stop of the swing mechanism to control the deflection of the two-dimensional galvanometer, so as to realize the pixel-by-pixel tunable optical output of the diffractive field based on the in-pixel speckle noise elimination and Gaussian distribution-free diffractive structure.

[0167] In the embodiment of the present application, the diffractive field optical output method also includes the diffractive field printing system, which comprises:

[0168] S10: obtaining the information of the diffractive field to be printed.

[0169] In the embodiment of the present application, the information of the diffractive field to be printed can be picture information.

[0170] S20: decomposing and encoding the wavefront information of the diffractive field to be printed by using the diffractive pixel, wherein the diffractive pixel includes a band-limited speckle and a Gaussian distribution-free diffractive structure.

[0171] In the embodiment of the present application, the amplitude and phase factor information is encoded into the amplitude and phase transmittance distribution map of the corresponding diffractive pixel by using the diffractive inversion calculation method, wherein the diffractive inversion calculation method includes an optimization algorithm under the band-limited speckle and Gaussian distribution-free illumination light field, and the optimization algorithm includes but is not limited to holographic calculation, iteration, simulated annealing or genetic algorithm; the amplitude and / or phase transmittance distribution map is input and refreshed into the object light path of the diffractive field laser printing system; and the object light reproduces the sub-wavefront information by diffracting the amplitude and / or phase transmittance distribution map.

[0172] S30: the diffractive pixels are recorded on the diffractive field recording material 17 by the interference of the object light and the reference light of the diffractive field printing system one by one to print the diffractive field, wherein the object light is formed by the object light path composed of the first illumination light field imaging optical subsystem of the diffractive field printing system; the diffractive pixel forms the speckle and Gaussian distribution-free wavefront information in the near field and the far field of the diffractive field at the same time; the wavefront information of the diffractive pixel is modulated by the refreshing of the object light and / or the transformation of the reference light; the wavefront information is decomposed into a plurality of sub-wavefront information, the sub-wavefront information is encoded to form a data structure with the diffractive pixel as a unit, the diffractive pixel unit contains the amplitude and phase factor information of the sub-wavefront information, and the phase factor information includes at least one of the first phase factor, the second phase factor and the high-order phase factor.

[0173] In the embodiment of the present application, the refreshing of the object light includes refreshing the amplitude and / or phase transmittance distribution map formed by the data structure encoding of the spatial light modulator corresponding to the object light path to realize the modulation.

[0174] The adjustment of the intensity of the reference light includes: translating the diffractive optical device to adjust the position of the diffractive optical device. In other embodiments, the position of the diffractive optical device can also be adjusted by rotating the diffractive optical device, or by simultaneously rotating and translating the diffractive optical device.

[0175] The adjustment of the direction of the reference light includes: (1) modulating the angle of the galvanometer; (2) modulating the angle of the galvanometer and adjusting the position of the diffractive field recording material; (3) modulating the angle of the galvanometer and adjusting the position of the diffractive optical device; (4) modulating the angle of the galvanometer, adjusting the position of the diffractive field recording material, and adjusting the position of the diffractive optical device.

[0176] Embodiment 6

[0177] As shown in Figure 10 Embodiments of the present application provide a diffractive field laser printing system, which includes a light source 1, an illumination optical subsystem, an imaging optical subsystem, a reference light subsystem, a mechanical motion subsystem, and a control subsystem.

[0178] The illumination optical subsystem includes a beam splitter, and the light emitted by the light source 1 enters the illumination optical subsystem and is split by the beam splitter into a first illumination light field and a second illumination light field. The imaging optical subsystem includes a diffractive optical device 4, a spatial light modulator 7, and a Fourier transform lens. The spatial light modulator 7 is located at the input face of the Fourier transform lens, and the spatial light modulator 7 is used to modulate the data structure corresponding to the sub-wavefront information and form the sub-wavefront information of the diffractive field on the output face of the Fourier transform lens. The first illumination light field illuminates the imaging optical subsystem, so that the first illumination light field passes through the diffractive optical device 4, the spatial light modulator 7, and the Fourier transform lens in turn, and simultaneously forms a limited-band diffraction-limited spot and a Gaussian-removed light field distribution on the input face and the output face of the Fourier transform lens. The reference light subsystem includes a galvanometer 13 and a relay lens group. The second illumination light field enters the reference light subsystem, so that the second illumination light field passes through the galvanometer 13 and the relay lens group in turn, and forms a reference light field on the output face of the relay lens group. The spot formed by the reference light field coincides with the output face of the Fourier transform lens or the image face of the output face. The mechanical motion subsystem includes a galvanometer driving device and a translation device. The galvanometer driving device is used to drive the galvanometer to rotate in two dimensions. The translation device is used to drive the diffractive field recording material 17 to move in translation. The photosensitive surface of the diffractive field recording material 17 coincides with the output face of the Fourier transform lens or the image face of the output face. The control subsystem is used to control the image refresh of the spatial light modulator 7 and the motion of the mechanical motion subsystem.

[0179] Specifically, in embodiments of the present application, the light source 1 is a continuous laser.

[0180] In the embodiment of the present application, the beam splitter is a half-transmission half-reflection mirror 11, and in the embodiment of the present application, the illumination optical subsystem further comprises an expander collimator 2, the expander collimator 2 comprises an expander mirror 20 and a collimator mirror 19, the diffractive optical device 4 is arranged between the expander mirror 20 and the collimator mirror 19, and the half-transmission half-reflection mirror 11 is arranged between the light source 1 and the expander collimator 2.

[0181] In the embodiment of the present application, the spatial light modulator 7 is a digital micromirror device display 26, and the Fourier transform lens adopts a Fourier transform lens group 8. In the embodiment of the present application, the imaging optical subsystem comprises the digital micromirror device display 26, a total reflection prism 27, the Fourier transform lens group 8, a field stop 9, a micro-imaging lens group 22, an auto-focusing optical path 30 and a monitoring camera 25, wherein the monitoring camera 25 is used to observe the situation of the diffraction field of the system output on the surface of the diffraction field recording material 17. The reference light subsystem comprises a galvanometer 13, a relay lens group and an aperture stop 18. The relay lens group comprises a lens 14 and a lens 15; the galvanometer 13 can vibrate in two dimensions.

[0182] In the embodiment of the present application, the translation device 16 is a two-dimensional translation stage, and the diffraction field recording material 17 is arranged on the two-dimensional translation stage, and the two-dimensional translation stage adjusts the reciprocating movement of the diffraction field recording material 17 along the optical axis direction. In the embodiment of the present application, the two-dimensional translation stage comprises a two-dimensional precision translation stage, and in the embodiment of the present application, the size of the two-dimensional translation stage affects the size of the diffraction field recording material 17 carried thereon. By increasing the carrying area of the two-dimensional translation stage, the area of the diffraction field recording material 17 can be increased, and further, the area of the formed diffraction field can be increased. The diffraction field recording material 17 in the embodiment of the present application is a photosensitive material.

[0183] In the embodiment of the present application, the mechanical motion subsystem further comprises a translation mechanism, a rotation mechanism and an auto-focusing driving mechanism (not shown in the figure), the galvanometer driving device is a swing mechanism (not shown in the figure), and the swing mechanism can drive the galvanometer 13 to swing. The diffractive optical device 4 is installed on the translation mechanism, and the translation mechanism moves reciprocally along the optical axis direction to drive the diffractive optical device 4 to move; the rotation mechanism is used to drive the diffractive optical device 4 to rotate in space, and in the embodiment of the present application, the translation mechanism is installed on the rotation mechanism, and the rotation of the rotation mechanism drives the rotation of the translation mechanism, and further, drives the rotation of the diffractive optical device 4. The auto-focusing driving mechanism is used to drive the auto-focusing optical path to do servo motion, so as to realize accurate focusing by the auto-focusing optical path. In other embodiments, the diffractive optical device 4 can also be arranged on the rotation mechanism, and the rotation mechanism is arranged on the translation mechanism. The translation mechanism drives the rotation mechanism to do two-dimensional translation motion, and further, drives the diffractive optical device 4 to do two-dimensional translation motion. The rotation of the rotation mechanism drives the rotation of the diffractive optical device 4.

[0184] The control subsystem is electrically connected with the switch of the light source 1, the spatial light modulator 7, the mechanical motion subsystem, the automatic focusing optical path 30 and the monitoring camera 25, and is used for coordinately controlling the switch of the light source 1, the image refreshing of the spatial light modulator 7, the rotation of the galvanometer 13, the two-dimensional translation motion of the translation device 16 and the translation mechanism, and the rotation of the rotation mechanism.

[0185] The control subsystem comprises an electric control box 28, an industrial computer 29 and control software thereof. The control subsystem is used for coordinately controlling the motion of each component in the mechanical motion subsystem, the switch of the laser, the refreshing of the digital micro-mirror device display 26, the real-time monitoring of the monitoring camera 25 and the automatic focusing optical path 30.

[0186] The diffractive field laser printing system in the embodiment of the application further comprises the mirror 12, the dichroic mirror 24 and the mechanical frame structure 10. The micro-imaging lens group 22 comprises a first micro-imaging lens group 221 and a second micro-imaging lens group 222, wherein the first micro-imaging lens group 221 is arranged away from the translation device 16, and the second micro-imaging lens group 222 is arranged close to the translation device 16; the number of the dichroic mirrors 24 is two, wherein one dichroic mirror 24 is arranged between the first micro-imaging lens group 221 and the second micro-imaging lens group 222, and the other dichroic mirror 24 is arranged between the field stop 9 and the first micro-imaging lens group 221.

[0187] In the embodiment of the application, the light output by the automatic focusing optical path 30 reaches the dichroic mirror 24, so as to realize the automatic focusing of the object light to the diffractive field recording material 17. In the embodiment of the application, the light formed by the first illumination optical field illumination imaging optical subsystem is object light.

[0188] In the embodiment, one operation mode of the diffractive field laser printing system is as follows: the control software sends a cycle instruction to the electric control system of the electric control box 28, the electric control system controls the motion of the diffractive optical device 4, the motion of the translation device 16 and the translation mechanism and the rotation of the swing mechanism in parallel, after the above four are all moved to the positions, a signal is sent to control the digital micro-mirror device display 26 to refresh the image and to turn on the laser, the laser is exposed on the diffractive field recording material 17 through the imaging optical subsystem and the reference optical subsystem to complete a recording cycle of a sub-wavefront. Then the above process is repeated by a second instruction to complete the recording of a second sub-wavefront. Until all the sub-wavefronts are recorded.

[0189] Specifically, in the embodiment of the application, the optical output principle of the diffractive field laser printing system comprises:

[0190] S1: the light emitted by the light source 1 reaches the illumination optical subsystem, and is split by the beam splitter to form a first illumination optical field and a second illumination optical field.

[0191] Specifically, in the embodiment of the present application, the laser emitted by the light source 1 is divided into two beams by the half-transmission half-reflection mirror 11, one transmitted beam and one reflected beam. The transmitted beam is the first illumination light field, and the reflected beam is the second illumination light field; the transmitted beam continues to enter the beam expander 20 and the collimating mirror 19 of the beam expander collimator 2 of the illumination optical subsystem.

[0192] S2: The first illumination light field illuminates the imaging optical subsystem, and sequentially passes through the diffractive optical device 4, the spatial light modulator 7 and the Fourier transform lens, and simultaneously forms a limited-band annihilation spot and a non-Gaussian light field distribution on the input face and the output face of the Fourier transform lens.

[0193] In the embodiment of the present application, the light beam passing through the beam expander 20 and the collimating mirror 19 further passes through the diffractive optical device 4 to form the illumination light beam 3, which is reflected by the mirror 12 to the total reflection prism 27 to form the limited-band annihilation spot and the non-Gaussian illumination light field 5; the illumination light field 5 illuminates the digital micromirror device display 26, which displays the information coding of the wavelet front in the embodiment 2 to form the data structure corresponding to the sub-pixel. The digital micromirror device display 26 is located on the input face of the Fourier transform lens group 8, and after the light passes through the digital micromirror device display 26, an annihilation spot noise and a non-Gaussian distributed wavelet front is formed on the output face of the Fourier transform lens group 8, that is, an annihilation spot noise and a non-Gaussian distributed light field is formed. The field diaphragm 9 is located on the output face of the Fourier transform lens group 8, and the light field passes through the field diaphragm 9 to reach the dichroic mirror 24, and passes through the first micro-imaging lens group 221 to reach the other dichroic mirror 24. The control subsystem can control the auto-focusing light path 30 to make the dichroic mirror 24 automatically focus, and the light further passes through the second micro-imaging lens group 222 to form a reduced first light spot on the diffraction field recording material 17.

[0194] S3: The second illumination light field illuminates the reference light subsystem to form an adjustable reference light, and the output face of the Fourier transform lens or the image face 23 of the output face coincides with the illumination face of the reference light; the interference between the reference light and the object light forms a diffraction field, wherein the object light is formed by the first illumination light field imaging optical subsystem of the diffraction field printing system.

[0195] In the embodiment, the reflected light of the half-transmission half-reflection mirror 11 passes through the aperture diaphragm 18 after being reflected by the mirror 12, then is incident on the two-dimensional galvanometer, and the light is reflected by the two-dimensional galvanometer to enter the relay lens group composed of the lens 14 and the lens 15, and is reflected by the mirror 12 to the surface of the diffraction field recording material 17 to form a second light spot, which coincides with the first light spot. The interference between the two light beams forms a diffraction structure on the diffraction field recording material 17, that is, a diffraction field is printed. In the embodiment of the present application, the control subsystem can control the monitoring camera 25 to monitor the diffraction field formed on the diffraction field recording material 17 in real time.

[0196] The embodiment of the present application also includes a diffraction field optical output method, which adopts the diffraction field printing system, and includes:

[0197] S10: obtaining diffraction field information to be printed.

[0198] In the embodiment of the present application, the information of the diffraction field to be printed can be picture information.

[0199] S20: decomposing and encoding the wavefront information of the diffraction field to be printed by using a diffraction pixel, wherein the diffraction pixel includes a limited-band annihilation speckle and a Gaussian-distribution-removed diffraction structure.

[0200] In the embodiment of the present application, the amplitude and phase factor information is encoded into the amplitude and phase transmittance distribution map of the corresponding diffraction pixel by using a diffraction inversion calculation method, wherein the diffraction inversion calculation method includes an optimization algorithm under the illumination light field of the limited-band annihilation speckle and the Gaussian-distribution-removed diffraction structure, and the optimization algorithm includes holographic calculation, iteration, simulated annealing or genetic algorithm; the amplitude and / or phase transmittance distribution map is input and refreshed into the object light path of the diffraction field laser printing system; and the object light reproduces the sub-wavefront information by diffraction on the amplitude and / or phase transmittance distribution map.

[0201] S30: the diffraction pixels are recorded on the diffraction field recording material 17 by the interference of the object light and the reference light of the diffraction field printing system one by one to print the diffraction field; wherein the object light is formed by the object light path composed of the first illumination light field imaging optical subsystem of the diffraction field printing system; the diffraction pixels form the wavefront information of the annihilation speckle and the Gaussian-distribution-removed diffraction structure in the near field and the far field of the diffraction field of the diffraction pixel at the same time; the wavefront information of the diffraction pixel is modulated by the refreshing of the object light and / or the transformation of the reference light; the wavefront information is decomposed into several sub-wavefront information, the sub-wavefront information is encoded to form a data structure with the diffraction pixel as a unit, the diffraction pixel unit contains the amplitude and phase factor information of the sub-wavefront information, and the phase factor information includes at least one of the first phase factor, the second phase factor and the high-order phase factor.

[0202] In the embodiment of the present application, the refreshing of the object light includes refreshing the amplitude and / or phase transmittance distribution map formed by the data structure coding of the spatial light modulator on the object light path to realize the modulation.

[0203] The adjustment of the intensity of the reference light includes: adjusting the position of the diffraction optical device by panning and / or rotating the diffraction optical device.

[0204] The adjustment of the direction of the reference light includes: (1) adjusting the angle of the modulation mirror; (2) adjusting the angle of the modulation mirror and the position of the diffraction field recording material; (3) adjusting the angle of the modulation mirror and the position of the diffraction optical device; (4) adjusting the angle of the modulation mirror, the position of the diffraction field recording material and the position of the diffraction optical device.

[0205] Embodiment 7

[0206] As Figure 11 shown, the embodiment of the present application provides a diffraction field laser printing system, which comprises a light source 1, an illumination optical subsystem, an imaging optical subsystem, a reference light subsystem, a mechanical motion subsystem and a control subsystem.

[0207] The illumination optical subsystem comprises a beam splitter, the light emitted by the light source 1 enters the illumination optical subsystem and is split by the beam splitter into a first illumination light field and a second illumination light field; the imaging optical subsystem comprises a diffractive optical device 4, a spatial light modulator 7 and a Fourier transform lens, the spatial light modulator 7 is located at the input face of the Fourier transform lens, the spatial light modulator 7 is used to modulate the data structure corresponding to the sub-wavefront information and form the sub-wavefront information of the diffraction field on the output face of the Fourier transform lens, wherein the first illumination light field illuminates the imaging optical subsystem, so that the first illumination light field passes through the diffractive optical device 4, the spatial light modulator 7 and the Fourier transform lens in turn, and a limited-band dissipation speckle and a de-Gaussian light field distribution are formed on the input face and the output face of the Fourier transform lens at the same time; the reference light subsystem comprises a galvanometer 13 and a relay lens group, the second illumination light field enters the reference light subsystem, so that the second illumination light field passes through the galvanometer 13 and the relay lens group in turn, and a reference light field is formed on the output face of the relay lens group; wherein the light spot formed by the reference light field coincides with the output face of the Fourier transform lens or the image face 23 of the output face; the mechanical motion subsystem comprises a galvanometer driving device and a translation device, the galvanometer driving device is used to drive the galvanometer to rotate in two dimensions; the translation device is used to drive the diffraction field recording material 17 to move in translation, wherein the photosensitive surface of the diffraction field recording material 17 coincides with the output face of the Fourier transform lens or the image face; the control subsystem is used to control the image refresh of the spatial light modulator 7 and the motion of the mechanical motion subsystem.

[0208] Specifically, in the embodiment of the present application, the light source 1 is a nanosecond pulsed laser.

[0209] In the embodiment of the present application, the beam splitter is a half-transmission half-reflection mirror 11, in the embodiment of the present application, the illumination optical subsystem further comprises an expansion collimator 2, the expansion collimator 2 comprises an expansion mirror 20 and a collimating mirror 19, the diffractive optical device 4 is arranged on the side of the collimating mirror 19 away from the expansion mirror 20, and the half-transmission half-reflection mirror 11 is arranged between the light source 1 and the expansion collimator 2.

[0210] In the embodiment of the present application, the spatial light modulator 7 is a phase type spatial light modulator, and the Fourier transform lens is a Fourier transform lens group 8. In the embodiment of the present application, the imaging optical subsystem includes the phase type spatial light modulator, the polarization beam splitter prism 21, the Fourier transform lens group 8, the field stop 9, the micro-imaging lens group 22, the monitoring camera 25 and the automatic focusing light path 30. The reference light subsystem includes the galvanometer 13, the relay lens group and the aperture stop 18; the relay lens group includes the lens 14 and the lens 15; the galvanometer 13 can vibrate in two dimensions.

[0211] In the embodiment of the present application, the translation device 16 is a two-dimensional translation stage, and the diffraction field recording material 17 is arranged on the two-dimensional translation stage, and the two-dimensional translation stage adjusts the reciprocating movement of the diffraction field recording material 17 along the optical axis direction. In the embodiment of the present application, the two-dimensional translation stage includes a two-dimensional precision translation stage, and in the embodiment of the present application, the size of the two-dimensional translation stage affects the size of the diffraction field recording material 17 carried thereon, and by increasing the carrying area of the two-dimensional translation stage, the area of the diffraction field recording material 17 can be increased, and thus the area of the formed diffraction field can be increased. The diffraction field recording material 17 in the embodiment of the present application is a photosensitive material.

[0212] In the embodiment of the present application, the mechanical motion subsystem further includes a translation mechanism (not shown in the figure), a rotation mechanism (not shown in the figure) and an automatic focusing driving system (not shown in the figure), the translation mechanism (not shown in the figure) is used to drive the diffraction optical device 4 to move in space; the diffraction optical device 4 is installed on the translation mechanism, and the translation mechanism moves reciprocally along the optical axis direction to drive the diffraction optical device 4 to move; the rotation mechanism is used to drive the diffraction optical device 4 to rotate in space, in the embodiment of the present application, the translation mechanism is installed on the rotation mechanism, and the rotation of the rotation mechanism drives the rotation of the translation mechanism, and thus drives the rotation of the diffraction optical device 4. The galvanometer driving device is a swing mechanism (not shown in the figure), which can drive the galvanometer 13 to swing. The automatic focusing driving system drives the automatic focusing light path 30 to move, so as to realize the automatic focusing of the light path. In other embodiments, the diffraction optical device 4 can also be arranged on the rotation mechanism, and the rotation mechanism is arranged on the translation mechanism, the translation mechanism drives the rotation mechanism to move in two dimensions, and thus drives the diffraction optical device 4 to move in two dimensions, and the rotation of the rotation mechanism drives the rotation of the diffraction optical device 4.

[0213] In the embodiment of the present application, the control subsystem is electrically connected with the switch of the light source 1, the spatial light modulator 7, the mechanical motion subsystem and the monitoring camera 25, and the control subsystem is used to coordinately control the switch of the light source 1, the image refreshing of the spatial light modulator 7, the rotation of the galvanometer 13, the two-dimensional translation movement of the translation device 16 and the translation mechanism, the rotation of the rotation mechanism, control the servo movement of the automatic focusing driving system to drive the automatic focusing light path 30, and control the real-time detection of the monitoring camera 25. The control subsystem includes the electric control box 28, the industrial computer 29 and the control software thereof.

[0214] The diffractive field laser printing system of the embodiment of the present application further comprises a mirror 12, two dichroic mirrors 24 and a mechanical frame structure (not shown in the figure). In the embodiment of the present application, the micro-imaging lens group 22 comprises a first micro-imaging lens group 221 and a second micro-imaging lens group 222, wherein the first micro-imaging lens group 221 is arranged away from the translation device 16 and the second micro-imaging lens group 222 is arranged close to the translation device 16; the number of the two dichroic mirrors 24 is two, wherein one dichroic mirror 24 is arranged between the first micro-imaging lens group 221 and the second micro-imaging lens group 222 and the other dichroic mirror 24 is arranged between the field stop 9 and the first micro-imaging lens group 221.

[0215] Another operation mode of the diffractive field laser printing system in the embodiment is as follows: the control software sends an instruction to the electric control system of the electric control box 28, and the electric control system controls the diffractive optical device 4 and the galvanometer 13 to move to a position and then keep still. Then a cycle instruction is entered, the electric control system controls the translation device 16 to move to a position, sends a signal to control the phase spatial light modulator to refresh an image and turn on the laser, and the laser is exposed on the photosensitive material through the imaging optical subsystem and the reference light subsystem to complete a cycle of recording of a sub-wavefront. Then a second cycle instruction is entered to repeat the above process to complete recording of a second sub-wavefront. Until all the sub-wavefronts are recorded.

[0216] Specifically, in the embodiment of the present application, the working principle of the diffractive field laser printing system is as follows:

[0217] S1: the light emitted by the light source 1 reaches the illumination optical subsystem and is split by the beam splitter to form a first illumination light field and a second illumination light field.

[0218] Specifically, in the embodiment of the present application, the laser emitted by the light source 1 is split into two beams of light by the half-transmission half-reflection mirror 11, one of which is transmitted light and the other of which is reflected light. The transmitted light is the first illumination light field and the reflected light is the second illumination light field. The transmitted light enters the expansion collimator 2 of the expansion mirror 20 and the collimation mirror 19.

[0219] S2: the first illumination light field illuminates the imaging optical subsystem, and the first illumination light field sequentially passes through the diffractive optical device 4, the spatial light modulator 7 and the Fourier transform lens to form a limited-band diffraction-limited spot and a Gaussian-removed light field distribution on the input face and the output face of the Fourier transform lens at the same time.

[0220] In the embodiment of the present application, the light beam passing through the beam expander 20 and the collimator 19 forms the illumination light beam 3 after entering the diffractive optical device 4, the illumination light beam 3 is reflected to the polarization beam splitter prism 21 through the mirror 12, forming the limited band annihilation spot, the Gaussian illumination light field 5; the illumination light field 5 illuminates the phase spatial light modulator, and the phase spatial light modulator displays the information coding of the wave front of the sub-wave front of the embodiment 2 to form the data structure corresponding to the sub-pixel. The phase spatial light modulator 7 is located on the input surface of the Fourier transform lens group 8, and the light passes through the phase spatial light modulator 7 to form the annihilation spot noise, the Gaussian distribution of the sub-wave front on the output surface of the Fourier transform lens group 8, that is, the annihilation spot noise, the Gaussian distribution of the light field distribution 6. The field stop 9 is located on the output surface of the Fourier transform lens group 8, the light beam passes through the field stop 9 to reach the dichroic mirror 24, and passes through the first micro-imaging lens group 221 to reach another dichroic mirror 24. The control subsystem can control the autofocus optical path 30 to automatically focus the dichroic mirror 24, and the light further passes through the second micro-imaging lens group 222 to form a reduced first light spot on the diffractive field recording material 17.

[0221] S3: The second illumination light field illuminates the reference light subsystem to form an adjustable reference light, and the output surface of the Fourier transform lens or the image surface 23 of the output surface coincides with the illumination surface of the reference light; the interference between the reference light and the object light forms a diffractive field, wherein the object light is formed by the first illumination light field illumination optical subsystem of the diffractive field printing system.

[0222] In the embodiment, the reflected light of the half-transmission half-reflection mirror 11 passes through the aperture diaphragm 18 after being reflected by the mirror 12, then enters the two-dimensional galvanometer, and the light passes through the galvanometer 13 to enter the relay lens group composed of the lens 14 and the lens 15, and is reflected to the surface of the diffractive field recording material 17 through the mirror 12 to form a second light spot. The second light spot coincides with the first light spot of the sub-wave front formed by the transmitted light of the half-transmission half-reflection mirror 11 on the surface of the diffractive field recording material 17. The diffractive structure is formed on the diffractive field recording material 17 by the interference of the two light beams.

[0223] In the embodiment of the present application, the diffractive field optical output method also includes the diffractive field printing system described above, which comprises:

[0224] S10: Obtain the information of the diffractive field to be printed.

[0225] In the embodiment of the present application, the information of the diffractive field to be printed can be picture information.

[0226] S20: Decompose and encode the wave front information of the diffractive field to be printed by using the diffractive pixel, wherein the diffractive pixel includes the limited band annihilation spot and the Gaussian distribution of the diffractive structure.

[0227] In this embodiment of the invention, the amplitude and phase factor information is encoded into amplitude and phase transmittance distribution maps of corresponding diffraction pixels using a diffraction inversion calculation method. The diffraction inversion calculation method includes band-limited speckle removal and optimization algorithms under Gaussian-free illumination fields. The optimization algorithms include holographic calculation, iteration, simulated annealing, or genetic algorithms. The amplitude and / or phase transmittance distribution maps are input and the object light path of the diffraction field laser printing system is refreshed. The object light reconstructs the sub-wavefront information through diffraction of the amplitude and / or phase transmittance distribution maps.

[0228] S30: Diffraction pixels are recorded one by one on the diffraction field recording material 17 through the interference of the object light and the reference light of the diffraction field printing system, thus printing the diffraction field; wherein, the object light is formed by the object light optical path composed of the first illumination light field illuminating the imaging optical subsystem of the diffraction field printing system; the diffraction pixels simultaneously form wavefront information with smear removal and Gaussian distribution removal in the near field and far field of their diffraction field; the wavefront information of the diffraction pixels is modulated by refreshing the object light and / or changing the reference light; the change of the reference light includes parameter tuning by modulating the intensity and / or direction of the reference light; the wavefront information is decomposed into several sub-wavefront information, and the sub-wavefront information is encoded into a data structure with diffraction pixels as units. The diffraction pixel unit contains the amplitude and phase factor information of the sub-wavefront information, and the phase factor information includes at least one of the first phase factor, second phase factor and higher-order phase factor.

[0229] In this embodiment of the invention, the object light refresh includes refreshing the amplitude and / or phase transmittance distribution map formed by the data structure encoding corresponding to the spatial light modulator on the object light path to achieve modulation.

[0230] Adjusting the intensity of the reference light includes translating and / or rotating the diffractive optics to adjust their position.

[0231] The adjustment of the direction of the reference light includes: (1) modulating the angle of the galvanometer. (2) modulating the angle of the galvanometer and adjusting the position of the diffraction field recording material. (3) modulating the angle of the galvanometer and adjusting the position of the diffraction optical device. (4) modulating the angle of the galvanometer, adjusting the position of the diffraction field recording material, and adjusting the position of the diffraction optical device.

[0232] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. It can be applied to various fields suitable for the invention. Other modifications can be readily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the invention is not limited to the specific details and examples shown and described herein.

Claims

1. A diffractive field printing system, characterized by, The imaging system comprises a light source, an illumination optical subsystem, an imaging optical subsystem, a reference light subsystem, a mechanical motion subsystem and a control subsystem, The illumination optical subsystem comprises a beam splitter, and light emitted by the light source enters the illumination optical subsystem and is split by the beam splitter into a first illumination light field and a second illumination light field; The imaging optical subsystem comprises a diffractive optical device, a spatial light modulator and a Fourier transform lens, the spatial light modulator is located at the input face of the Fourier transform lens, the spatial light modulator is used to modulate the data structure corresponding to the sub-wavefront information and form the sub-wavefront information of the diffraction field on the output face of the Fourier transform lens, wherein the first illumination light field illuminates the imaging optical subsystem, so that the first illumination light field sequentially passes through the diffractive optical device, the spatial light modulator and the Fourier transform lens, and a limited-band diffraction spot and a de-Gaussian light field distribution are formed on the input face and the output face of the Fourier transform lens; The reference light subsystem comprises a galvanometer and a relay lens group, the second illumination light field enters the reference light subsystem, so that the second illumination light field sequentially passes through the galvanometer and the relay lens group, and a reference light light field is formed on the output face of the relay lens group; wherein the light spot formed by the reference light light field coincides with the output face of the Fourier transform lens or the image face of the output face; The mechanical motion subsystem comprises a galvanometer driving device and a translation device, the galvanometer driving device is used to drive the galvanometer to rotate in two dimensions, and the translation device is used to drive the diffraction field recording material to move in translation, wherein the photosensitive face of the diffraction field recording material coincides with the output face of the Fourier transform lens or the image face of the output face; The control subsystem is used to control the image refreshing of the spatial light modulator and the motion of the mechanical motion subsystem.

2. The diffractive field printing system of claim 1, wherein, The imaging optical subsystem further comprises any one or several of a micro-imaging lens group, a field stop, an autofocus optical path and a real-time monitoring optical path, the micro-imaging lens group is used to image the output face of the Fourier transform lens onto the photosensitive face of the diffraction field recording material to form the image face of the output face; the field stop is used to control the size of the recording unit diffraction pixel of the diffraction field; the autofocus optical path is used to ensure that the output face of the Fourier transform lens or the image face of the output face is focused near the surface of the diffraction field recording material.

3. The diffractive field printing system of claim 1, wherein, The reference light subsystem further comprises an aperture stop, and the aperture stop is used to control the shape and size of the light spot formed by the reference light light field.

4. The diffractive field printing system of claim 2, wherein, The mechanical motion subsystem further comprises a translation mechanism and / or a rotation mechanism, the translation mechanism is used to drive the diffractive optical device to move in translation in space, and the rotation mechanism is used to drive the diffractive optical device to move in rotation in space; The mechanical motion subsystem further comprises an autofocus driving mechanism, and the autofocus driving mechanism is used to drive the autofocus optical path to move in servo.

5. The diffractive field printing system of claim 1, wherein, The control subsystem is electrically connected with the switch of the light source, the spatial light modulator and the mechanical motion subsystem, and is used for coordinating control of the switch of the light source, image refreshing of the spatial light modulator, rotation of the galvanometer and two-dimensional translation motion of the translation device to operate in time sequence.

6. The diffractive field printing system of claim 1, wherein, The illumination optical subsystem further comprises a beam expander collimator, and the beam expander collimator comprises a beam expander and a collimator, wherein the beam splitter is arranged between the light source and the beam expander collimator, or the beam splitter is arranged on the side of the beam expander collimator away from the light source.

7. The diffractive field printing system of claim 1, wherein, The light source comprises a laser light source, a super radiation light source or a light emitting diode, the laser light source comprises a continuous laser light source or a pulsed laser light source, and the pulsed laser light source comprises a nanosecond pulsed laser light source, a picosecond pulsed laser light source or a femtosecond pulsed laser light source.

8. A method of diffractive field optical output, characterized by, The diffraction field printing system of any one of claims 1-7 comprises: acquiring diffraction field information to be printed; using diffraction pixels to decompose and encode wavefront information of the diffraction field to be printed, wherein the diffraction pixels comprise limited-band annihilation spots and Gaussian-distribution-free diffraction structures; the diffraction pixels are recorded on a diffraction field recording material one by one through interference of object light and reference light of the diffraction field printing system to print a diffraction field; wherein the object light is formed by illuminating the object light optical path composed of the imaging optical subsystem by the first illumination light field of the diffraction field printing system; the diffraction pixels form annihilation spots and Gaussian-distribution-free wavefront information in the near field and far field of the diffraction pixel diffraction field at the same time; the wavefront information of the diffraction pixels is modulated through refreshing of the object light and / or transformation of the reference light; the transformation of the reference light comprises adjusting the intensity of the reference light and / or the direction of the reference light; the wavefront information is decomposed into a plurality of sub-wavefront information, and the sub-wavefront information is encoded to form a data structure with the diffraction pixels as units, and the amplitude and phase factor information of the sub-wavefront information are contained in the diffraction pixel unit, and the phase factor information comprises at least one of a first phase factor, a second phase factor and a high-order phase factor.

9. The diffractive field optical output method of claim 8, wherein, The use of diffraction pixels to decompose and encode the wavefront information of the diffraction field to be printed comprises: using a diffraction inversion calculation method to encode the amplitude and the phase factor information into an amplitude and phase transmittance distribution map of the corresponding diffraction pixels, wherein the diffraction inversion calculation method comprises an optimization algorithm under limited-band annihilation spots and Gaussian-distribution-free illumination light field, and the optimization algorithm comprises holographic calculation, iteration, simulated annealing or genetic algorithm; inputting and refreshing the amplitude and / or phase transmittance distribution map into the object light optical path of the diffraction field laser printing system; the object light reproduces the sub-wavefront information through diffraction of the amplitude and / or phase transmittance distribution map.

10. The diffractive field optical output method of claim 8, wherein, the refreshing of the object light comprises refreshing the amplitude and / or phase transmittance distribution map formed by the data structure encoding of the spatial light modulator corresponding to the object light optical path to realize modulation; the adjustment of the intensity of the reference light comprises: translating and / or rotating the diffractive optical device to adjust the position of the diffractive optical device; The adjustment of the direction of the reference light comprises: modulating the angle of the galvanometer; or, modulating the angle of the galvanometer and adjusting the position of the diffractive field recording material, or, modulating the angle of the galvanometer and adjusting the position of the diffractive optical device, or, modulating the angle of the galvanometer, adjusting the position of the diffractive field recording material and adjusting the position of the diffractive optical device.

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