A three-dimensional aerial imaging device based on strong laser ionization of air

Abstract

The invention discloses a three-dimensional aerial imaging device based on strong laser ionization of air, comprising: a pulse light source, an optical shutter, a galvanometer assembly, a lens assembly and a controller, wherein a pulse light beam generated by the pulse light source is emitted through a light outlet, an optical shutter is arranged at the light outlet for opening or closing the light outlet, a galvanometer assembly is arranged on the irradiation path of the pulse light beam for changing the irradiation direction of the pulse light beam in a horizontal or vertical direction, a lens assembly is used to focus the pulse light beam reflected by the galvanometer assembly to ionize the air at a position corresponding to the imaging area to form a holographic real image, a controller signal connects the pulse light source and the optical shutter, and adjusts the brightness of the ionized luminous point by controlling the energy of the pulse light source output pulse and the closing of the optical shutter. The optical shutter cooperates with the pulse light source to control the brightness of different positions in the holographic imaging, and the coordination of the brightness can display the picture sense and layering sense of the holographic imaging, thereby improving the display effect of the air ionization display picture.

Description

Technical Field

[0001] The invention relates to the field of air display, in particular to a three-dimensional air imaging device based on strong laser ionization of air. Background Art

[0002] The existing air ionization system includes three modules: high-power pulse light source, beam control and air ionization. The beam control module includes a two-dimensional high-speed scanning galvanometer and a lens assembly composed of a zoom lens and a flat-field focusing lens. The galvanometer system is composed of a combination of galvanometers in the x-direction and y-direction, which can make the reflected light beam scan in the x-direction and y-direction within a plane; the zoom lens changes the position of the focal point of the ionization area in the z-direction by changing the focal length of the lens. Combined with the galvanometers in the x-direction and y-direction, the position of the ionization point can be controlled to change in three-dimensional space; the flat-field focusing lens controls the light beam to form a uniformly sized focused light spot in the entire plane, suppressing the distortion of the light spot. In order to increase the pixels of the display screen, a spatial light modulator is added to the beam control system. The purpose of light wave modulation is achieved by modulating the amplitude, phase, polarization state and other parameters of the light field. The light beam modulated by the spatial light modulator forms multiple focusing points after passing through the focusing module, thereby increasing the pixels of the display screen.

[0003] However, in actual screen display, there are still demands for displaying discontinuous images and different display brightness requirements for different areas of the screen. Therefore, the device of the present invention solves the above demands by controlling the discontinuity and brightness of the ionized bright spots, thereby improving the display effect. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a three-dimensional aerial imaging device based on strong laser ionization of air, which can improve the display effect of air ionization display pictures by adjusting the discontinuity and brightness of ionized bright light points at different positions in the imaging area.

[0005] According to an embodiment of the present invention, a three-dimensional aerial imaging device based on strong laser ionization of air includes: a pulse light source, an optical shutter, a galvanometer assembly, a lens assembly and a controller, wherein the pulse light source is provided with a light outlet, and the pulse light beam generated by the pulse light source is emitted through the light outlet, the optical shutter is arranged at the light outlet and is used to open or close the light outlet, the galvanometer assembly is arranged on the irradiation path of the pulse light beam and is used to change the irradiation direction of the pulse light beam in the horizontal or vertical direction, the lens assembly is used to focus the pulse light beam reflected by the galvanometer assembly to ionize the air at a corresponding position to form a holographic real image, and the controller signal connects the pulse light source and the optical shutter, and adjusts the energy of the pulse light beam when the optical shutter closes the light outlet.

[0006] According to the three-dimensional aerial imaging device based on strong laser ionization of air in the embodiment of the present invention, the brightness of different positions in the holographic imaging can be controlled by using an optical shutter in combination with a pulse light source. The coordination of brightness can increase the sense of picture and layering of the displayed holographic imaging, thereby improving the display effect of the air ionization display.

[0007] According to some embodiments of the present invention, it further includes: a beam expander, which is arranged between the pulse light source and the optical shutter to control the beam waist spot size of the light beam.

[0008] According to some embodiments of the present invention, the device further includes: a photodetector, which is arranged between the pulse light source and the optical shutter to monitor the average power of the pulse output by the pulse light source.

[0009] According to some embodiments of the present invention, a beam splitter is provided between the pulse light source and the optical shutter, and the beam splitter is used to reflect part of the light beam output by the pulse light source onto the plurality of photodetectors.

[0010] According to some embodiments of the present invention, it further includes: a spatial light modulator, which is arranged between the pulse light source and the galvanometer assembly and is used to adjust the parameters of the pulse light beam.

[0011] According to some embodiments of the present invention, the method further includes: a heat sink, which is disposed between the pulse light source and the optical shutter and is used to reduce heat accumulation generated when the optical shutter blocks the pulse light beam.

[0012] According to some embodiments of the present invention, the transmittance of the beam splitter is A, 0.99≤A≤0.995.

[0013] According to some embodiments of the present invention, the lens assembly includes a zoom lens and a flat-field focusing lens, and the zoom lens is located between the flat-field focusing lens and the galvanometer assembly.

[0014] According to some embodiments of the present invention, the repetition frequency of the multiple pulse light sources is the same, the pulse width of the pulse light source is 50fs-100ns, the pulse energy of the pulse light source is 1μJ-200mJ, and the repetition frequency of the pulse light source is 50Hz-50MHz. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0017] Figure 1 A schematic structural diagram of a three-dimensional aerial imaging device based on strong laser ionization of air according to an embodiment of the present invention;

[0018] Figure 2 A schematic structural diagram of a pulse light source according to an embodiment of the present invention.

[0019] Reference numerals:

[0020] 1: Pulse light source; 1-2: Beam splitter; 1-3: Photodetector; 2: Beam expander; 3: Optical shutter; 4: Radiator; 5: Spatial light modulator; 6: Galvanometer assembly; 7: Lens assembly; 8: Holographic real image; 9: Controller. DETAILED DESCRIPTION

[0021] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0022] Reference below Figure 1 and Figure 2 A three-dimensional aerial imaging device based on strong laser ionization of air according to an embodiment of the present invention is described.

[0023] like Figure 1 As shown, the three-dimensional aerial imaging device based on strong laser ionization of air according to an embodiment of the present invention includes: a pulse light source 1, an optical shutter 3, a galvanometer assembly 6, a lens assembly 7 and a controller 9.

[0024] The pulse light source 1 may include a housing and a laser generator, the laser generator generates a pulse light beam, a light outlet is provided on the housing, the light beam is emitted through the light outlet, the laser generator signal is connected to the controller 9, and the controller 9 controls the energy of the light beam generated by the laser generator. The optical shutter 3 is provided at the light outlet for opening or closing the light outlet, and the optical shutter 3 may be provided on the housing of the pulse light source 1 and adjacent to the light outlet.

[0025] The galvanometer assembly 6 is arranged on the irradiation path of the pulse light beam and is used to change the irradiation direction of the pulse light beam in the horizontal or vertical direction. The lens assembly 7 is used to focus the pulse light beam reflected by the galvanometer assembly 6 to ionize the air at the corresponding position to form a holographic real image 8. In other words, the light beam is irradiated onto the galvanometer assembly 6 through the light outlet, and the galvanometer assembly 6 reflects the light beam, thereby controlling the irradiation direction of the light beam; the light beam passes through the lens assembly 7, and under the focusing action of the lens assembly 7, the light beam is focused at the focal position so that the spot diameter reaches a minimum value. At this time, the power per unit area of ​​the laser increases rapidly and reaches the air ionization threshold, thereby ionizing the air around the focus and forming a light spot. The galvanometer assembly 6 changes the position of the ionized light spot by changing the reflection direction of the light beam. Since the process of the galvanometer driving the light spot to move is extremely fast, the next focal point is ionized to form a light spot before the previous light spot disappears, thereby scanning near the focus of the lens assembly 7 to form a holographic real image 8.

[0026] Furthermore, the controller 9 signals the pulse light source 1 and the optical shutter 3, and adjusts the energy of the pulse light beam when the optical shutter 3 closes the light outlet. That is, when the light beam passes through the optical shutter 3 and is emitted to the galvanometer assembly 6, and then in the process of the galvanometer assembly 6 and the lens assembly 7 cooperating to form an image, the optical shutter 3 can control the light beam to be disconnected, and during the time when the optical shutter 3 blocks the light beam, the controller 9 controls the pulse light source 1 to adjust the energy of the light beam, thereby controlling the brightness of the light spot formed at the next ionization point.

[0027] Therefore, according to the three-dimensional aerial imaging device based on strong laser ionization of air according to the embodiment of the present invention, the optical shutter 3 cooperates with the pulse light source 1 to control the brightness of different positions in the holographic imaging image. The coordination of brightness can increase the picture sense and layering of the holographic imaging, thereby improving the display effect of the air ionization display picture.

[0028] According to some embodiments of the present invention, it also includes: a beam expander 2, which is arranged between the pulse light source 1 and the optical shutter 3 to control the waist spot size of the light beam. The light beam generated by the pulse light source 1 passes through the beam expander 2 and irradiates the optical shutter 3. The beam expander 2 can increase the waist spot area of ​​the light beam, thereby reducing the unit area optical power parameter of the spot, thereby increasing the service life of components. At the same time, in conjunction with the parameter optimization of the lens assembly 7, the size of the focused light focus can be further reduced, thereby reducing the pulse energy threshold of air ionization.

[0029] According to some embodiments of the present invention, it also includes: a photodetector 1-3, which is arranged between the pulse light source 1 and the optical shutter 3 to detect the output pulse beam power of the pulse light source 1. The light beam generated by the pulse light source 1 is irradiated on the photodetector 1-3 to detect the irradiated light beam power, and the power of the light beam output by the pulse light source 1 can be obtained by converting the light splitting ratio. In the process of beam ionization imaging, the photodetector 1-3 can monitor the power of the pulse light source 1 in real time to prevent the power fluctuation of the pulse light source 1 from affecting the imaging effect.

[0030] like Figure 2 As shown, in some specific embodiments, a beam splitter 1-2 is provided between the pulse light source 1 and the optical shutter 3. The beam splitter 1-2 is used to reflect part of the output light beam of the pulse light source 1 to multiple photodetectors 1-3. The beam splitter 1-2 is arranged to cross the extension direction of the light beam. The light beam generated by the pulse light source 1 is irradiated on the beam splitter 1-2. Most of the light beam passes through the beam splitter 1-2 and shines on the optical shutter 3 for imaging. A small part of the light beam is reflected by the beam splitter 1-2 and shines on the photodetector 1-3.

[0031] By setting the beam splitter 1-2, not only can the photodetector 1-3 be convenient for detecting the power of the pulse light source 1, but also the structural design of the imaging device can be simplified to prevent the photodetector 1-3 from blocking the light beam and affecting the imaging effect. Moreover, the beam splitter 1-2 has a simple structure and is easy to implement.

[0032] According to some embodiments of the present invention, it also includes: a spatial light modulator 5, which is arranged between the pulse light source 1 and the galvanometer assembly 6 to adjust the parameters of the pulse light beam. The spatial light modulator 5 modulates the spatial distribution of the light wave. The spatial light modulator 5 contains many independent units, which are arranged in a one-dimensional or two-dimensional array in space. Each unit can independently receive the control of an optical signal or an electrical signal, and change its own optical properties (transmittance, reflectivity, refractive index, etc.) according to the signal, thereby modulating the light wave passing through it. The spatial light modulator 5 is located between the optical shutter 3 and the galvanometer assembly 6. When the light beam passes through the spatial light modulator 5, its optical parameters (amplitude, intensity, phase or polarization state) are modulated by each unit of the spatial light modulator 5, resulting in a beam of output light with a new spatial distribution of optical parameters.

[0033] By setting up a spatial light modulator 5, the amplitude, phase, polarization state and other parameters of the light beam generated by the pulse light source 1 are adjusted. The light beam modulates the light field through the spatial light modulator 5 and forms multiple focal points after passing through the lens assembly 7, thereby improving the imaging quality of the three-dimensional figure.

[0034] like Figure 1As shown, according to some embodiments of the present invention, it also includes: a heat sink 4, which is arranged between the pulse light source 1 and the optical shutter 3, and is used to dissipate the heat accumulation generated when the optical shutter 3 blocks the pulse light beam.

[0035] In this embodiment, the light beam generated by the pulse light source 1 will irradiate the optical shutter 3. When the optical shutter 3 blocks the light beam, the light is absorbed, so that the heat of the optical shutter 3 slowly accumulates. By providing a heat sink 4, the heat dissipation of the optical shutter 3 can be promoted, and the damage caused by excessive temperature of the optical shutter 3 can be prevented. Among them, the optical shutter 3 and the heat sink 4 can be arranged on the housing of the pulse light source 1.

[0036] According to some embodiments of the present invention, the transmittance of the beam splitter 1-2 is A, 0.99≤A≤0.995. That is, when the light beam is irradiated onto the beam splitter 1-2, 99%-99.5% of the light beam passes through the beam splitter 1-2 and shines on the optical shutter 3 for ionization imaging, and 0.5%-1% of the light beam is irradiated onto the photodetector 1-3 for detecting the power of the light beam. Since the amount of light required by the photodetector 1-3 in the process of detecting the power of the light beam is relatively low, the energy of the light beam in the ionization area can be increased, thereby improving the imaging effect.

[0037] According to some embodiments of the present invention, the lens assembly 7 includes a zoom lens and a flat-field focusing lens, the zoom lens is located between the flat-field focusing lens and the galvanometer assembly 6, the high-power pulse light source 1 outputs laser pulses, the light field is modulated by the spatial light modulator 5, and then reflected to the galvanometer assembly 6 to adjust its emission direction, the light beam passes through the zoom lens and the flat-field focusing lens and is focused to a designated point in the air ionization area, and finally the high-power laser ionizes the air molecules to form a luminous bright spot.

[0038] The zoom lens can adjust the distance between the focus and the zoom lens according to the imaging requirements, and then generate a three-dimensional holographic real image 8 by adjusting the focus position. The flat-field focusing lens and the zoom lens can be used to prevent the holographic real image 8 from bending and deforming during the imaging process. The control computer actively controls the spatial light modulator 5, the galvanometer assembly 6 and the lens assembly 7 to adjust the position of the laser ionization point and the pixels of the display image according to the image to be displayed.

[0039] According to some embodiments of the present invention, the repetition frequency of multiple pulse light sources 1 is the same, the pulse width of the pulse light source 1 is 50fs-100ns, the pulse energy of the pulse light source 1 is 1μJ-200mJ, and the repetition frequency of the pulse light source 1 is 50Hz-50MHz.

[0040] Other structures and operations according to the embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0041] In the description of the present invention, "first feature" or "second feature" may include one or more of the features.

[0042] In the description of the present invention, "plurality" means two or more.

[0043] In the description of the present invention, a first feature being “on” or “under” a second feature may include that the first and second features are directly in contact with each other, or may include that the first and second features are not in direct contact with each other but are in contact with each other via another feature therebetween.

[0044] In the description of the present invention, “on”, “over” and “above” a first feature from a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0045] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0046] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A three-dimensional aerial imaging device based on strong laser ionization of air, It is characterized in that include: A pulse light source (1), wherein the pulse light source (1) is provided with a light outlet, and the pulse light beam generated by the pulse light source (1) is emitted through the light outlet; An optical shutter (3), the optical shutter (3) being arranged at the light outlet and used for opening or closing the light outlet; A galvanometer assembly (6), the galvanometer assembly (6) being arranged on an irradiation path of the pulse light beam and used for changing the irradiation direction of the pulse light beam in a horizontal or vertical direction; A lens assembly (7), the lens assembly (7) being used to focus the pulse light beam reflected by the galvanometer assembly (6) so as to ionize the air at a corresponding position to form a holographic real image (8); A heat sink (4), the heat sink (4) being arranged between the pulse light source (1) and the optical shutter (3) and being used to reduce heat accumulation generated when the optical shutter (3) blocks the pulse light beam; A controller (9), wherein the controller (9) signals connect the pulse light source (1) and the optical shutter (3), and adjusts the energy of the pulse light beam when the optical shutter (3) closes the light outlet.

2. The three-dimensional aerial imaging device based on strong laser ionization of air according to claim 1, It is characterized in that Also includes: A beam expander (2), the beam expander (2) being arranged between the pulse light source (1) and the optical shutter (3) and used for controlling the beam waist spot size of the light beam.

3. The three-dimensional aerial imaging device based on strong laser ionization of air according to claim 1, It is characterized in that Also includes: A photoelectric detector (1-3), wherein the photoelectric detector (1-3) is arranged between the pulse light source (1) and the optical shutter (3) and is used to monitor the average power of pulses output by the pulse light source (1).

4. The three-dimensional aerial imaging device based on strong laser ionization of air according to claim 3, It is characterized in that A beam splitter (1-2) is provided between the pulse light source (1) and the optical shutter (3), the beam splitter (1-2) being arranged crosswise with the extension direction of the light beam, and the beam splitter (1-2) is used to reflect part of the light beam output by the pulse light source (1) onto the plurality of photodetectors (1-3).

5. The three-dimensional aerial imaging device based on strong laser ionization of air according to claim 4, It is characterized in that Also includes: A spatial light modulator (5) is provided between the pulse light source (1) and the galvanometer assembly (6) and is used to adjust light field parameters of the pulse light beam.

6. The three-dimensional aerial imaging device based on strong laser ionization of air according to claim 4, It is characterized in that The light transmittance of the beam splitter (1-2) is A, 0.99≤A≤0.

995.

7. The three-dimensional aerial imaging device based on strong laser ionization of air according to claim 1, It is characterized in that The lens assembly (7) comprises a zoom lens and a flat-field focusing lens, and the zoom lens is located between the flat-field focusing lens and the galvanometer assembly (6).

8. A three-dimensional aerial imaging device based on strong laser ionization of air according to any one of claims 1 to 7, It is characterized in that The repetition frequency of the plurality of pulse light sources (1) is the same; the pulse width of the pulse output by the pulse light source (1) is 5 fs-100 ns, the pulse energy is 1 μJ-200 mJ, and the pulse repetition frequency is 50 Hz-50 MHz.

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