CN107728243B - A non-dispersive polarization multiplexing grating and display device - Google Patents

Abstract

The present invention provides a non-dispersive polarization multiplexing grating and a display device. The grating includes a plurality of periodically arranged grating sub-units, and each grating sub-unit includes: one or more first embossed sub-grating units, one or more A plurality of second relief sub-grating units and one or more third relief sub-grating units; the first relief sub-grating unit, the second relief sub-grating unit and the third relief sub-grating unit are respectively used for red light, green light and Diffraction of blue light; the first relief sub-grating unit, the second relief sub-grating unit and the third relief sub-grating unit are etched on the surface of the same medium; any first relief sub-grating unit has a first height, any second relief sub-grating unit The grating unit has a second height, any third relief sub-grating unit has a third height, the first height is greater than the second height, and the second height is greater than the third height. The invention realizes achromatism and polarization multiplexing, and can form multi-view images.

Description

A non-dispersive polarization multiplexing grating and display device

technical field

The present invention relates to the field of display technology, more specifically, to a non-dispersive polarization multiplexing grating and a display device.

Background technique

Subwavelength microstructures can achieve optical properties that cannot be achieved by ordinary optical components because their period constants are smaller than the wavelength of incident light. For example, on the one hand, the grating etched by the subwavelength microstructure can achieve polarization sensitivity, and the function of the polarization beam splitter can be completed through the surface structure; on the other hand, for specific polarized light, the subwavelength microstructure can achieve wavelength insensitivity, and Complete the modulation of signal light with multiple wavelengths.

For the microstructure of optical components, there are currently subwavelength microstructure polarizing beam splitters and subwavelength microstructure achromatic focusing lenses. Among them, the subwavelength microstructure polarization beam splitter is based on the strict coupled wave theory, and a subwavelength dielectric grating with a high aspect ratio is obtained. The incident light is incident at a Bragg angle, and only the 0th-order TM mode diffracted light exists in the diffracted light order. The diffracted light of the +1-order TE mode has different diffraction angles, and can be used for polarization multiplexing, but cannot be used for multiple wavelengths; the sub-wavelength microstructure achromatic focusing lens, through the non-periodic coupling dielectric resonator array, makes the near-infrared three-wavelength The signal light is focused to the same point, but it is generally only designed for a certain polarized light and cannot be polarized multiplexed.

Moreover, the microstructures with the above two functions can only be used in the near-infrared band at present.

The signal light wavelengths processed by gratings in these display systems are all in the near-infrared region, and the imaging color is distorted, and the diffracted images cannot be viewed from multiple perspectives.

Contents of the invention

The present invention provides a non-dispersive polarization multiplexing grating that overcomes the problem that the wavelength of the signal light processed by the grating in the above-mentioned display system is in the near-infrared region, the imaging has some chromatic aberration, resulting in color distortion, and the diffracted image cannot be viewed from multiple angles of view. and display device.

According to one aspect of the present invention, a grating is provided, including a plurality of periodically arranged grating subunits, each of the plurality of grating subunits includes: one or more first relief sub-grating units, one or A plurality of second relief sub-grating units and one or more third relief sub-grating units; the first relief sub-grating units are used for diffraction of red light, and the second relief sub-grating units are used for diffraction of green light Diffraction, the third relief sub-grating unit is used for diffraction of blue light; the first relief sub-grating unit, the second relief sub-grating unit and the third relief sub-grating unit are etched on the surface of the same medium; Any of the first relief sub-grating units has a first height, any of the second relief sub-grating units has a second height, any of the third relief sub-grating units has a third height, and the first height greater than the second height, the second height being greater than the third height.

Preferably, each of the plurality of grating sub-units further includes: any one of the first relief sub-grating units becomes a protrusion alone, or is combined with any of the second relief sub-grating units and/or Any of the third embossed sub-grating units is stacked to form a protrusion; any of the second embossed sub-grating units alone becomes a protrusion, or, with any of the first embossed sub-grating units and/or any One said third embossed sub-grating unit is overlaid to form a protrusion; any said third embossed sub-grating unit becomes a protrusion alone, or, with any one of said first embossed sub-grating unit and/or any The second embossed sub-grating unit is overlaid to form a protrusion.

Preferably, the medium is an optical waveguide, or a substrate on the surface of an optical waveguide.

Preferably, the exterior of the grating is in contact with air.

Preferably, the grating includes: the ratio of the period of the first relief sub-grating unit to the wavelength of red light is less than 1; the ratio of the period of the second relief sub-grating unit to the wavelength of green light is less than 1; the third The ratio of the period of the relief sub-grating unit to the blue light wavelength is less than 1.

Preferably, the grating includes: the duty cycle of the first relief sub-grating unit is less than 0.8; the duty cycle of the second relief sub-grating unit is less than 0.8; the duty cycle of the third relief sub-grating unit less than 0.8.

Preferably, the grating includes: the aspect ratio of the first relief sub-grating unit is less than 1; the aspect ratio of the second relief sub-grating unit is less than 1; the aspect ratio of the third relief sub-grating unit is less than 1.

Preferably, the grating includes: the grating has different diffraction angles for incident signal light of different polarization states; the polarization state of the outgoing signal light diffracted by the grating is the same as the polarization state of the incident signal light corresponding to the outgoing signal light; The diffraction angles of the grating are the same for the red light, the green light and the blue light of the same polarization state incident on the signal light.

According to another aspect of the present invention, a display device is provided, including: a microdisplay, used to emit signal light; a polarizer, used to form polarized signal light; a polarization mixer, used to mix the polarized signal light ; The grating described in any one of the above is used to modulate and diffract the polarized signal light in different polarization states mixed by the polarization mixer to different angles to form a multi-view image; the polarizer includes: TE polarizer , used to form the polarized signal light of the TE mode, TM polarizer, used to form the polarized signal light of the TM mode; the signal light from the microdisplay passes through the polarizer, the polarization mixer and the grating.

Preferably, a collimator is further included, configured to collimate the signal light emitted by the microdisplay into parallel signal light, so that the polarizer polarizes the parallel signal light to form polarized signal light.

The present invention provides a non-dispersive polarization multiplexing grating and display device, by setting one or more first relief sub-grating units with different heights etched on the surface of the same medium in each grating sub-unit, one or more A second relief sub-grating unit and one or more third relief sub-grating units; and the first relief sub-grating unit is used for diffraction of red light, and the second relief sub-grating unit is used for diffraction of green light Diffraction, the third embossed sub-grating unit is used to diffract blue light, so that the non-dispersive polarization multiplexing grating can diffract red light, green light and blue light at the same diffraction angle, realizing the function of achromatic aberration, and keeping the image True; the non-dispersive polarization multiplexing grating can modulate signal lights of different polarization states to realize polarization multiplexing, and diffract to different angles to form a multi-view image; the non-dispersive polarization multiplexing grating will polarization multiplex The function is integrated with the multi-wavelength achromatic function and can be used in the visible light band. Moreover, the display device provided by the present invention can be used by multiple people to view images from multiple perspectives, and can also be used in the field of vehicle display and the like.

Description of drawings

FIG. 1 is a schematic structural diagram of a grating subunit of a grating in an embodiment of the present invention;

2 is a schematic diagram of a partial structure of a grating subunit of a grating in an embodiment of the present invention;

3 is a schematic diagram of the diffraction of the red signal light of the TE mode incident on the grating in an embodiment of the present invention;

4 is a schematic diagram of the diffraction of the green signal light of the TE mode incident on the grating in an embodiment of the present invention;

5 is a schematic diagram of the diffraction of the blue signal light of the TE mode incident on the grating in an embodiment of the present invention;

6 is a schematic diagram of the diffraction of the red signal light of the TM mode incident on the grating in an embodiment of the present invention;

7 is a schematic diagram of the diffraction of the green signal light of the TM mode incident on the grating in an embodiment of the present invention;

8 is a schematic diagram of the diffraction of the blue signal light of the TM mode incident on the grating in an embodiment of the present invention;

Fig. 9 is a schematic diagram of a transmissive grating display in an embodiment of the present invention;

Fig. 10 is a schematic diagram of a reflective grating display in an embodiment of the present invention;

FIG. 11 is a schematic diagram of signal source generation of a display device in an embodiment of the present invention.

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

Fig. 1 is a schematic structural diagram of a grating subunit of a grating in an embodiment of the present invention. Comprising: one or more first embossed sub-grating units, one or more second embossed sub-grating units and one or more third embossed sub-grating units; the first embossed sub-grating units are used for diffracting red light , the second relief sub-grating unit is used for diffraction of green light, and the third relief sub-grating unit is used for diffraction of blue light; the first relief sub-grating unit, the second relief sub-grating unit and The third relief sub-grating units are etched on the surface of the same medium; any of the first relief sub-grating units has a first height, any of the second relief sub-grating units has a second height, and any of the first relief sub-grating units has a second height. The three-relief sub-grating unit has a third height, the first height is greater than the second height, and the second height is greater than the third height.

Specifically, the grating includes a transmission type and a reflection type, and has a nanostructure. The structure of the grating exhibits long-range order and short-range disorder. The long-range order means that the grating includes a plurality of periodically arranged grating subunits; the short-range disorder means that the grating subunits in the plurality of grating In each grating sub-unit, after the first relief sub-grating unit, the second relief sub-grating unit and the third relief sub-grating unit are overlaid, the grating shape has no period.

Further, the height of the first relief sub-grating unit in the grating is the first height, the height of the second relief sub-grating unit in the grating is the second height, and the third relief sub-grating unit in the grating The height is a third height, the first height is greater than the second height, and the second height is greater than the third height.

The first relief sub-grating unit, the second relief sub-grating unit and the third relief sub-grating unit are etched on the same medium surface, which means that the first relief sub-grating unit, the second relief sub-grating unit Both the grating unit and the third relief sub-grating unit are made of the same material as the medium.

Further, the grating with the above structure has the property that the diffraction angles are different for incident signal lights of different polarization states; but the diffraction angles are the same for incident signal lights of the same polarization state.

The present invention provides a non-dispersive polarization multiplexing grating. In each grating sub-unit, one or more first relief sub-grating units with different heights etched on the surface of the same medium, one or more first relief sub-grating units, one or more second Two embossed sub-grating units and one or more third embossed sub-grating units; and the first embossed sub-grating unit is used for diffracting red light, and the second embossed sub-grating unit is used for diffracting green light, The third embossed sub-grating unit is used to diffract blue light, so that the non-dispersive polarization multiplexing grating has different diffraction angles for incident signal light of different polarization states, but for incident signal light of the same polarization state, the diffraction angle The same property, and through this property, signal light of different polarization states can be modulated to realize polarization multiplexing, diffracted to different angles, and form a multi-view image.

Based on the above-mentioned embodiment, each grating sub-unit in the multiple grating sub-units further includes: any one of the first relief sub-grating units alone becomes a protrusion, or, any one of the second relief sub-grating units and /or any one of the third relief sub-grating units is laminated to form a protrusion; any of the second relief sub-grating units alone becomes a protrusion, or, with any of the first relief sub-grating units and/or Or any of the third relief sub-grating units is stacked to form a protrusion; any of the third relief sub-grating units alone becomes a protrusion, or, with any of the first relief sub-grating units and/or Any one of the second relief sub-grating units is stacked to form a protrusion.

Based on the above embodiments, the grating includes: the medium is an optical waveguide, or is a base material on the surface of an optical waveguide.

Specifically, the optical waveguide is a dielectric device that guides light waves to propagate therein, including high-transparency optical glass and optical plastic. The substrate on the surface of the optical waveguide refers to coating one or more layers of substrates on the surface of the optical waveguide, and the substrate is a metal material or a dielectric material.

Further, the first embossed sub-grating unit, the second embossed sub-grating unit and the third embossed sub-grating unit are overlaid on the surface of the same medium, which means that the first embossed sub-grating unit, the first embossed sub-grating unit The second relief sub-grating unit and the third relief sub-grating unit are laminated on the surface of the same optical waveguide or the surface of the substrate on the optical waveguide.

Based on the above embodiment, the exterior of the grating is in contact with air.

Based on the above embodiment, the grating includes: the ratio of the period of the first relief sub-grating unit to the wavelength of red light is less than 1; the ratio of the period of the second relief sub-grating unit to the wavelength of green light is less than 1; the The ratio of the period of the third relief sub-grating unit to the blue light wavelength is less than 1.

Based on the above embodiment, the grating includes: the duty ratio of the first relief sub-grating unit is less than 0.8; the duty ratio of the second relief sub-grating unit is less than 0.8; the duty ratio of the third relief sub-grating unit The empty ratio is less than 0.8.

Based on the above embodiment, the grating includes: the aspect ratio of the first relief sub-grating unit is less than 1; the aspect ratio of the second relief sub-grating unit is less than 1; the depth of the third relief sub-grating unit is The aspect ratio is less than 1. Specifically, the formula for calculating the aspect ratio is:

where bd is the aspect ratio, d is the duty cycle, h is the ridge height, and T is the period.

2 is a schematic diagram of a partial structure of a grating subunit of a grating in an embodiment of the present invention, the grating includes a plurality of periodically arranged grating subunits, each of the plurality of grating subunits includes: One or more first embossed sub-grating units, one or more second embossed sub-grating units and one or more third embossed sub-grating units; the first embossed sub-grating units are used for diffraction of red light, so The second relief sub-grating unit is used for diffraction of green light, and the third relief sub-grating unit is used for diffraction of blue light; the first relief sub-grating unit, the second relief sub-grating unit and the The third relief sub-grating unit is etched on the surface of the same medium; any of the first relief sub-grating units has a first height, any of the second relief sub-grating units has a second height, and any of the third relief sub-grating units has a first height. The sub-grating unit has a third height, the first height is greater than the second height, and the second height is greater than the third height.

Further, as shown in FIG. 2, the first relief sub-grating unit 1, the second relief sub-grating unit 2 and the third relief sub-grating unit 3 are sequentially etched on the surface of the optical waveguide 5, and the first relief sub-grating unit 1. The second embossed sub-grating unit 2 and the third embossed sub-grating unit 3 are laminated to form a protrusion, and the outside of the grating is in contact with a gas medium 4, and the gas medium 4 is air.

Table 1 The theoretical value table of the maximum diffraction efficiency of the TE mode signal light incident on the grating

Table 2 The theoretical value table of the maximum diffraction efficiency of the signal light of the TM mode incident on the grating

As shown in Table 1, R is red signal light, G is green signal light, and B is blue signal light, and the ratio of the period of the first relief sub-grating unit 1 to the wavelength of the red signal light is 0.948, so The ratio of the period of the second relief sub-grating unit 2 to the wavelength of the green signal light is 0.951, and the ratio of the period of the third relief sub-grating unit 3 to the wavelength of the blue signal light is 0.948. The ratio of the period of the first relief sub-grating unit 1 to the wavelength of the red signal light is less than 1; the ratio of the period of the second relief sub-grating unit 2 to the wavelength of the green signal light is less than 1; the third relief sub-grating unit The ratio of the period of 3 to the wavelength of the blue signal light is less than 1. As shown in Table 2, R is red signal light, G is green signal light, and B is blue signal light. The ratio of the period of the first embossed sub-grating unit 1 to the wavelength of the red signal light is 0.948, The ratio of the period of the second relief sub-grating unit 2 to the wavelength of the green signal light is 0.951, and the ratio of the period of the third relief sub-grating unit 3 to the wavelength of the blue signal light is 0.948. The ratio of the period of the first relief sub-grating unit 1 to the wavelength of the red signal light is less than 1; the ratio of the period of the second relief sub-grating unit 2 to the wavelength of the green signal light is less than 1; the third relief sub-grating unit The ratio of the period of 3 to the wavelength of the blue signal light is less than 1.

Further, as shown in Table 1 and Table 2, when the signal light of the TE mode or the signal light of the TM mode is incident, the duty ratio of the first relief sub-grating unit 1 is 0.312203, and the duty cycle of the second relief sub-grating unit 1 is 0.312203. The duty ratio of the grating unit 2 is 0.313658, and the duty ratio of the third relief sub-grating unit 3 is 0.266726. The duty ratio of the first relief sub-grating unit 1 is less than 0.8; the duty ratio of the second relief sub-grating unit 2 is less than 0.8; the duty ratio of the third relief sub-grating unit 3 is less than 0.8.

Further, as shown in Table 1, when the signal light of the TE mode is incident, the aspect ratio of the first relief sub-grating unit 1 is 0.7423, and the aspect ratio of the second relief sub-grating unit 2 is 0.7005, The aspect ratio of the third relief sub-grating unit 3 is 0.6569. The aspect ratio of the first relief sub-grating unit 1 is less than 1; the aspect ratio of the second relief sub-grating unit 2 is less than 1; the aspect ratio of the third relief sub-grating unit 3 is less than 1.

Further, as shown in Table 1, the ±1st order diffraction efficiencies of the red signal light, the green signal light and the blue signal light are all higher than 47%, and the 0th order diffraction efficiency is close to 0. As shown in Table 2, the diffraction efficiencies of the ±1st order of the red signal light, the green signal light and the blue signal light are all lower than 1%, and the diffraction efficiency of the 0th order is relatively high. It can be further known from this that the period of the grating in this embodiment is 18.9 microns.

Based on the above embodiment, the grating includes: when the signal light of the TE mode is incident on the grating, +1 order diffracted light and -1 order diffracted light are generated; when the signal light of the TM mode is incident on the grating , resulting in 0th order diffracted light.

Based on the above-mentioned embodiment, the grating has different diffraction angles for incident signal light of different polarization states; the polarization state of the outgoing signal light diffracted by the grating is the same as the polarization state of the incident signal light corresponding to the outgoing signal light; the grating For the red light, green light and blue light incident signal light of the same polarization state, the diffraction angles are the same.

3 is a schematic diagram of the diffraction of the red signal light of the TE mode incident on the grating in an embodiment of the present invention. As shown in FIG. 3 , the red signal light 101 of the TE mode is incident on the grating 100 at an angle θ _i , Produced +1 order diffracted light 103, the diffraction angle of described +1 order diffracted light is Produced simultaneously - 1 order diffracted light 102, the diffraction angle of described- 1 order diffracted light is

4 is a schematic diagram of the diffraction of the green signal light of the TE mode incident on the grating in an embodiment of the present invention. As shown in FIG. 4 , the green signal light 201 of the TE mode is incident on the grating 100 at an angle θ _i , Produced +1 order diffracted light 203, the diffraction angle of described +1 order diffracted light is Simultaneously produced-1 order diffracted light 202, the diffraction angle of described-1 order diffracted light is

FIG. 5 is a schematic diagram of the diffraction of the blue signal light of the TE mode incident on the grating in an embodiment of the present invention. As shown in FIG. 5 , the blue signal light 301 of the TE mode is incident on the grating 100 at an angle θ _i Above, the +1st-order diffracted light 303 is generated, and the diffraction angle of the +1st-order diffracted light is Simultaneously produced-1 order diffracted light 302, the diffraction angle of described-1 order diffracted light is

Further, the diffraction angles of the diffracted light corresponding to the incident signal light in the same polarization state are the same, therefore, the diffraction angle of the red signal light-first-order diffracted light Diffraction angle of green signal light-1st order diffracted light and the diffraction angle of the blue signal light-first-order diffracted light equal in size. Diffraction angle of red signal light + 1st order diffracted light Diffraction angle of green signal light + 1st order diffracted light and the diffraction angle of the blue signal light + 1st order diffracted light equal in size.

6 is a schematic diagram of the diffraction of the red signal light of the TM mode incident on the grating in an embodiment of the present invention. As shown in FIG. 6, the red signal light 401 of the TM mode is incident on the grating 100 at an angle θ _i , The 0th-order diffracted light 402 is produced, and the diffraction angle of the 0-order diffracted light is

7 is a schematic diagram of the diffraction of the green signal light of the TM mode incident on the grating in an embodiment of the present invention. As shown in FIG. 7, the green signal light 501 of the TM mode is incident on the grating 100 at an angle θ _i , Produced 0 order diffracted light 502, the diffraction angle of described 0 order diffracted light is

8 is a schematic diagram of the diffraction of the blue signal light of the TM mode incident on the grating in an embodiment of the present invention. As shown in FIG. 8, the blue signal light 601 of the TM mode is incident on the grating 100 at an angle θ _i , the 0th-order diffracted light 602 is generated, and the diffraction angle of the 0-order diffracted light is

Further, the diffraction angles of the diffracted light corresponding to the incident signal light in the same polarization state are the same, therefore, the diffraction angle of the 0th order diffracted light of the red signal light Diffraction angle of 0th order diffracted light of green signal light and the diffraction angle of the 0th order diffracted light of the blue signal light equal in size.

FIG. 9 is a schematic diagram of a transmissive grating display in an embodiment of the present invention. As shown in FIG. 9 , the colored and polarized mixed signal light 700 is incident on the grating 100 at a diffraction angle _θi , and +1 order diffracted light 703 is generated. , the +1st-order diffracted light 703 carries the TM polarization information of the signal light 700, and the diffraction angle of the +1st-order diffracted light is The observer 706 can observe the corresponding image information; the -1 order diffracted light 701 is produced, and the -1 order diffracted light 701 carries the TM polarization information of the signal light 700, and the diffraction angle of the -1 order diffracted light is The observer 704 can observe the corresponding image information; the 0th order diffracted light 702 is produced, and the 0th order diffracted light 702 carries the TE polarization information of the signal light 700, and the diffraction angle of the 0th order diffracted light is The observer 705 can observe the corresponding image information. It should be noted that, in this embodiment, only the diffraction angle of the +1st order diffracted light is The diffraction angle of the -1 order diffracted light is and the diffraction angle of the 0th order diffracted light is But not limited to this.

FIG. 10 is a schematic diagram of a reflective grating display in an embodiment of the present invention. As shown in FIG. 10 , the colored and polarized mixed signal light 800 is incident on the grating 100 at a diffraction angle _θi , and +1 order diffracted light 803 is generated. , the +1st-order diffracted light 803 carries the TM polarization information of the signal light 800, and the diffraction angle of the +1st-order diffracted light is The observer 806 can observe the corresponding image information; the -1 order diffracted light 801 is produced, and the -1 order diffracted light 801 carries the TM polarization information of the signal light 800, and the diffraction angle of the -1 order diffracted light is The observer 804 can observe the corresponding image information; the 0th order diffracted light 802 is produced, and the 0th order diffracted light 802 carries the TE polarization information of the signal light 800, and the diffraction angle of the 0th order diffracted light is The observer 805 can observe the corresponding image information. It should be noted that, in this embodiment, only the diffraction angle of the +1st order diffracted light is The diffraction angle of the -1 order diffracted light is and the diffraction angle of the 0th order diffracted light is But not limited to this.

Based on the above embodiments, the present invention provides a display device, including: a microdisplay, used to emit signal light; a polarizer, used to form polarized signal light; a polarization mixer, used to mix the polarized signal light; The grating according to any one of the above-mentioned embodiments is used for diffracting the modulated polarization signals in different polarization states mixed by the polarization mixer to different angles to form a multi-view image. The polarizer includes: a TE polarizer for forming polarized signal light of a TE mode, a TM polarizer for forming a polarized signal light of a TM mode; the signal light from the microdisplay passes through the a polarizer, the polarization mixer and the grating.

Based on the above embodiment, the display device further includes a collimator, configured to collimate the signal light emitted by the microdisplay into parallel signal light, so that the polarizer polarizes the parallel signal light to form a polarized signal light.

Fig. 11 is a schematic diagram of signal source generation of a display device in an embodiment of the present invention. As shown in Fig. 11, the first color microdisplay 911 emits image signal light, which is collimated by the first collimator 921 to form parallel light , is incident on the TE polarizer 931 to form a light wave 8010 carrying the TE component in the image signal light; at the other end, the second color microdisplay 912 emits image signal light different from the first color microdisplay 911, and undergoes a second collimation The collimation of the polarizer 922 forms parallel light, which is incident on the TM polarizer 932 to form the light wave 8011 carrying the TM component of the image signal light. The light waves 8010 and 8011 are incident on the polarization mixer 940 and combined to form a polarization mixed color image 800 .

Further, the polarization mixer 940 combines beams to form a polarization mixed color image 800. A multi-view image is formed through a transmission grating or a reflection grating described in the above embodiments. In this embodiment, a display device includes a first color microdisplay 911, a first collimator 921, a TE polarizer 931, a second color microdisplay 912, a second collimator 922, and a TM polarizer 932 , a polarization mixer 940, and a transmissive grating or a reflective grating.

The present invention provides a non-dispersive polarization multiplexing grating and display device, by setting one or more first relief sub-grating units with different heights etched on the surface of the same medium in each grating sub-unit, one or more A second relief sub-grating unit and one or more third relief sub-grating units; and the first relief sub-grating unit is used for diffraction of red light, and the second relief sub-grating unit is used for diffraction of green light Diffraction, the third embossed sub-grating unit is used to diffract blue light, so that the non-dispersive polarization multiplexing grating can diffract red light, green light and blue light at the same diffraction angle, realizing the function of achromatic aberration, and keeping the image True; the non-dispersive polarization multiplexing grating can modulate signal lights of different polarization states to realize polarization multiplexing, and diffract to different angles to form a multi-view image; the non-dispersive polarization multiplexing grating will polarization multiplex The function is integrated with the multi-wavelength achromatic function, and can be used in the visible light band; and the display device provided by the present invention can be used by multiple people to view images from multiple perspectives, and can also be used in the field of vehicle display.

Finally, the method of the present invention is only a preferred embodiment, and is not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. a kind of grating, the grating subelement including multiple periodic arrangements, each grating in multiple grating subelements is single Member includes: one or more first embossment sub-gratings units, one or more second embossment sub-gratings units and one or more Third embossment sub-gratings unit；The first embossment sub-gratings unit is used to carry out the diffraction of feux rouges, the second embossment sub-light Grid unit is used to carry out the diffraction of green light, and the third embossment sub-gratings unit is used to carry out the diffraction of blue light；It is characterized in that,

The first embossment sub-gratings unit, the second embossment sub-gratings unit and third embossment sub-gratings unit etching In same dielectric surface；

Any first embossment sub-gratings unit has the first height, and any second embossment sub-gratings unit has second Highly, any third embossment sub-gratings unit has third height, and first height is greater than second height, described Second height is greater than the third height.

2. grating according to claim 1, which is characterized in that each grating subelement in multiple grating subelements is into one Step includes:

Any first embossment sub-gratings unit individually becomes a protrusion, alternatively, with any second embossment sub-gratings Unit and/or any third embossment sub-gratings unit, which are folded, is carved into a protrusion；

Any second embossment sub-gratings unit individually becomes a protrusion, alternatively, with any first embossment sub-gratings Unit and/or any third embossment sub-gratings unit, which are folded, is carved into a protrusion；

Any third embossment sub-gratings unit individually becomes a protrusion, alternatively, with any first embossment sub-gratings Unit and/or any second embossment sub-gratings unit, which are folded, is carved into a protrusion.

3. grating according to claim 1, which is characterized in that the medium is optical waveguide, or is light guide surface Substrate.

4. grating according to claim 1, which is characterized in that contacted outside the grating with air.

5. grating according to claim 1 characterized by comprising

The period of the first embossment sub-gratings unit and the ratio of red light wavelength are less than 1；The second embossment sub-gratings unit Period and green wavelength ratio less than 1；The period of the third embossment sub-gratings unit and the ratio of blue light wavelength are less than 1。

6. grating according to claim 1 characterized by comprising

The duty ratio of the first embossment sub-gratings unit is less than 0.8；The duty ratio of the second embossment sub-gratings unit is less than 0.8；The duty ratio of the third embossment sub-gratings unit is less than 0.8.

7. grating according to claim 1 characterized by comprising

The depth-to-width ratio of the first embossment sub-gratings unit is less than 1；The depth-to-width ratio of the second embossment sub-gratings unit is less than 1； The depth-to-width ratio of the third embossment sub-gratings unit is less than 1.

8. grating according to claim 1 characterized by comprising

The grating is different to the incoming signal optical diffraction angle of different polarization states；The polarization of the optical grating diffraction output signal light The polarization state of state, incoming signal light corresponding with the output signal light is identical；The grating for same polarization state feux rouges, Green light and blue light incoming signal light, the angle of diffraction are identical.

9. a kind of display device characterized by comprising

Micro-display, for emitting signal light；

The polarizer is used to form polarization signal light；

Polarization combiner, for mixing the polarization signal light；

Grating described in any one of claims 1 to 8, for by the polarization combiner mix in different polarization states Polarization signal light modulation is diffracted into different angle, forms multi-view image；

The polarizer includes: the TE polarizer, is used to form the polarization signal light of TE mould, and the TM polarizer is used to form TM mould Polarization signal light；

Signal light from the micro-display sequentially passes through the polarizer, the polarization combiner and the grating.

10. display device according to claim 9, which is characterized in that further include collimator, be used for the micro-display The signal light of transmitting is collimated into parallel signal light, so that the polarizer is polarized the parallel signal light to form polarization signal Light.