WO2022017171A1 - 波导组件和包括波导组件的近眼显示设备 - Google Patents

波导组件和包括波导组件的近眼显示设备 Download PDF

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Publication number
WO2022017171A1
WO2022017171A1 PCT/CN2021/104696 CN2021104696W WO2022017171A1 WO 2022017171 A1 WO2022017171 A1 WO 2022017171A1 CN 2021104696 W CN2021104696 W CN 2021104696W WO 2022017171 A1 WO2022017171 A1 WO 2022017171A1
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Prior art keywords
grating
coupling
reflection
light
waveguide
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PCT/CN2021/104696
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English (en)
French (fr)
Inventor
马珂奇
徐钦锋
杜佳玮
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Ningbo Sunny Opotech Co Ltd
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Ningbo Sunny Opotech Co Ltd
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Priority to CN202180049670.0A priority Critical patent/CN115803662A/zh
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Anticipated expiration legal-status Critical
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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01—Head-up displays
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01—Head-up displays
    • G02B27/0101—Head-up displays characterised by optical features
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/18—Diffraction gratings
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
    • G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
    • G02B6/122—Basic optical elements, e.g. light-guiding paths
    • G02B6/124—Geodesic lenses or integrated gratings

Definitions

  • the present application relates to the technical field of optical transmission, and in particular, to a waveguide assembly and a near-eye display device including the waveguide assembly.
  • Near-eye display devices are mainly used to display pictures or videos to human eyes, and near-eye display devices can be widely used in fields such as virtual reality, augmented reality, mixed reality or military.
  • the near-eye display device includes components such as a light source assembly and a waveguide.
  • the waveguide is provided with an in-coupling area and an out-coupling area.
  • the light emitted by the light source assembly is coupled into the waveguide from the coupling-in area, and the light is then coupled out of the waveguide from the coupling-out area and transmitted to people. Eye.
  • the main purpose of the present application is to provide a waveguide assembly with high utilization rate of light energy, high exit pupil density, and uniform brightness, and a near-eye display device including the waveguide assembly.
  • An embodiment of the present application provides a waveguide assembly, including:
  • a coupling-in area disposed on a surface of the waveguide sheet, the coupling-in area is used to couple light into the waveguide sheet and make the light diffuse and transmit in the waveguide sheet;
  • an out-coupling grating provided on a surface of the waveguide sheet, the coupling-out grating is used to couple out the light coupled in from the coupling-in region out of the waveguide sheet;
  • the first reflection grating and the coupling-out grating are arranged on the same surface of the waveguide sheet and are located at the end of the coupling-out grating along the light transmission direction, the first-time reflection grating and the coupling-out grating
  • the groove lines are parallel, the period of the first reflection grating and the coupling-out grating is the same, and the diffraction efficiency of the second-order diffracted light in the diffraction order is set to the maximum, or the first reflection grating is the coupling grating.
  • Half of the out-coupling grating period and the diffraction efficiency of the first-order diffracted light in the diffraction order is set to be the maximum, and the first reflection grating is used to reflect the light passing through the out-coupling grating but not out-coupling back to the out-coupling The grating is then coupled out.
  • the first reflection grating includes a first reflection grating and a second reflection grating arranged in phase separation.
  • the first reflection grating is a sinusoidal grating, a rectangular grating, a blazed grating, or a slanted grating inclined toward the outcoupling grating.
  • the waveguide assembly further includes a second reflection grating, and the second reflection grating and the first reflection grating are provided on the same surface of the waveguide sheet;
  • the second reflection grating is opposite to the first reflection grating and is located on both sides of the coupling-out grating;
  • the groove lines of the second reflection grating are parallel to the groove lines of the outcoupling grating, the period of the second reflection grating is the same as the period of the coupling out grating, and the diffraction order of the second order diffracted light in the diffraction order
  • the efficiency is set to the maximum, or the period of the second reflection grating is half the period of the outcoupling grating and the diffraction efficiency of the first-order diffracted light in the diffraction order is set to the maximum;
  • the uncoupled light after being reflected by the first reflection grating is transmitted to the second reflection grating, and is reflected back to the outcoupling grating by the second reflection grating.
  • the first reflection grating includes a first reflection grating and a second reflection grating arranged in phase separation
  • the second reflection grating includes a third reflection grating and a fourth reflection grating arranged in phase separation
  • the first reflection grating and the third reflection grating are arranged opposite to each other
  • the second reflection grating and the fourth reflection grating are arranged opposite to each other.
  • the second reflection grating is a sinusoidal grating, a rectangular grating, a blazed grating, or a slanted grating inclined toward the outcoupling grating.
  • the outcoupling grating is a one-dimensional grating.
  • the coupling-out grating is composed of two one-dimensional gratings respectively provided on two surfaces of the waveguide sheet or composed of two one-dimensional gratings provided on the same surface of the waveguide sheet superimposed.
  • the included angle between the two one-dimensional gratings of the outcoupling grating is 50-70 degrees.
  • the coupling-out grating is a rectangular grating, a blazed grating, a tilted grating, a sinusoidal grating or a holographic grating, and the groove depth is 50-200 nm.
  • the first sub-reflection grating borders the outcoupling grating.
  • the width of the first reflection grating is greater than 3 mm.
  • the coupling-out grating is a rectangular grating
  • the first reflection grating and/or the second reflection grating is a tilted grating or a blazed grating.
  • the in-coupling region includes an in-coupling grating for coupling light into the waveguide sheet.
  • the coupled-in grating is a rectangular grating, a blazed grating, a slanted grating, a sinusoidal grating or a holographic grating, with a period of 300-600 nm and a groove depth of 40-500 nm.
  • the coupling-in region further includes a turning grating, and the turning grating is used for diffusing and transmitting the light coupled in from the coupling-in grating in the waveguide sheet.
  • the turning grating is a rectangular grating, a blazed grating, a tilted grating, a sinusoidal grating or a holographic grating, and has a period of 300-600 nm and a groove depth of 40-500 nm.
  • the in-coupling region and the out-coupling grating are located on the same surface of the waveguide sheet or are respectively located on two opposite surfaces of the waveguide sheet.
  • the thickness of the waveguide sheet is 0.3-2.5 mm
  • the material of the waveguide sheet is an optical material that is transparent to visible light
  • the refractive index of the waveguide sheet is 1.4-2.2.
  • An embodiment of the present application further provides a near-eye display device, including a projector and a waveguide assembly, where the waveguide assembly is the waveguide assembly described in any of the foregoing embodiments.
  • a first reflection grating is arranged on one side surface of the waveguide sheet, and the first reflection grating is parallel to the groove line of the outcoupling grating, and the period of the first reflection grating and the outcoupling grating is The same and the diffraction efficiency of the second-order diffracted light in the diffraction order is set to the maximum, or the first reflection grating is half of the outcoupling grating period and the diffraction efficiency of the first-order diffracted light in the diffraction order is set to the maximum, so that The light that passes through the out-coupling grating but is not coupled out is returned to the out-coupling grating by the first reflection grating to be coupled out, thereby improving the light energy utilization rate of the entire waveguide assembly and increasing the overall exit pupil density of the waveguide assembly.
  • the light that has been coupled out after being returned by the first reflection grating supplements the light that has been coupled out, the brightness uniformity of the light coupled out in the overall visible area of the waveguide sheet is improved.
  • the manufacturing process is simple, and the manufacturing is convenient.
  • the light that is not coupled out of the out-coupling grating for the first time can be returned to the out-coupling grating only after passing through a first-time reflection grating, and the utilization rate of light energy is higher.
  • FIG. 1 is a schematic structural diagram of a waveguide assembly provided by an embodiment of the present application
  • FIG. 2 is a side view of the waveguide assembly shown in FIG. 1;
  • FIG. 3 is a grating vector diagram of the waveguide assembly shown in FIG. 1;
  • FIG. 4 is a diagram of a simulation result of light diffraction of a waveguide assembly provided by an embodiment of the application
  • FIG. 5 is a schematic diagram of the waveguide assembly with grating vector shown in FIG. 1;
  • FIG. 6 is a schematic structural diagram of a waveguide assembly provided by an embodiment of the present application.
  • FIG. 7 is a schematic structural diagram of a waveguide assembly provided by an embodiment of the present application.
  • FIG. 8 is a schematic structural diagram of a waveguide assembly provided by an embodiment of the present application.
  • Figure 9 is a side view of a portion of the waveguide assembly shown in Figure 8.
  • Fig. 10 is a grating vector diagram of the waveguide assembly shown in Fig. 8;
  • Fig. 11 is a grating vector diagram of the waveguide assembly shown in Fig. 8;
  • Fig. 12 is a grating vector diagram of the waveguide assembly shown in Fig. 8;
  • Figure 13 is a grating vector diagram of the waveguide assembly shown in Figure 8.
  • FIG. 14 is a schematic structural diagram of a near-eye display device according to an embodiment of the present application.
  • FIG. 15 is a schematic structural diagram of a near-eye display device according to an embodiment of the present application.
  • Waveguide sheet 1. Waveguide sheet; 2. In-coupling region; 21. In-coupling grating; 22. Inflection grating; 3. Out-coupling grating; 4. First reflection grating; 41. First reflection grating; 42, Second reflection grating; 5. The second reflection grating; 51, the third reflection grating; 52, the fourth reflection grating; 6. Projector light machine.
  • FIG. 1 is a schematic structural diagram of a waveguide assembly provided by an embodiment of the present application.
  • the waveguide assembly provided in this embodiment includes:
  • Waveguide sheet 1
  • the coupling-in region 2 is arranged on a surface of the waveguide sheet 1, and the coupling-in region 2 is used to couple light into the waveguide sheet 1 and make the light diffuse and transmit in the waveguide sheet 1;
  • the coupling-out grating 3 is arranged on a surface of the waveguide sheet 1, and the coupling-out grating 3 is used for coupling the light coupled in from the coupling-in region 2 out of the waveguide sheet 1;
  • the first reflection grating 4 is arranged on the same surface of the waveguide plate 1 as the outcoupling grating 3 and is located at the end of the outcoupling grating 3 along the light transmission direction.
  • the first reflection grating 4 is parallel to the groove lines of the outcoupling grating 3 , the period of the first reflection grating 4 and the outcoupling grating 3 is the same and the diffraction efficiency of the second-order diffracted light in the diffraction order is set to the maximum, or the first reflection grating 4 is half the period of the coupling out grating 3 and the diffraction order
  • the diffraction efficiency of the first-order diffracted light in the second time is set to be the maximum, and the first-time reflection grating 4 is used to reflect the light passing through the out-coupling grating 3 but not out-coupled back to the out-coupling grating 3 and then out-coupling.
  • FIG. 2 is a side view of the waveguide assembly shown in FIG. 1 .
  • the working principle of the waveguide assembly is as follows:
  • the light is coupled into the waveguide sheet 1 through the coupling-in region 2 , and diffuses and transmits to the coupling-out grating 3 in the waveguide sheet 1 .
  • the coupling-out grating 3 couples the light A to the outside of the waveguide sheet 1, so that it can be observed by the human eye, that is, a visible area is formed.
  • the uncoupled light B will continue to propagate to the first reflection grating 4, the first reflection grating 4 will reflect the light B back out of the coupling grating 3, and then coupled out by the coupling out grating 3, that is, the light C, Ray C remains parallel to ray A.
  • FIG. 3 is a grating vector diagram of the waveguide assembly shown in FIG. 1 .
  • the coupling-in region 2 has a grating vector G0
  • the coupling-out grating 3 has a grating vector G1
  • the first reflection grating 4 has a grating vector G2. Since the first reflection grating 4 is parallel to the groove lines of the outcoupling grating 3, the grating vectors of the first reflection grating 4 and the outcoupling grating 3 are parallel to each other, so that the uncoupled light B is reflected by the first reflection grating. 4 is reflected back out of the grating 3. The period of the first reflection grating 4 determines its vector size.
  • the diffraction efficiency of the second-order diffracted light is set to be the largest among its diffraction orders, so that the light B is at the first reflection grating 4 .
  • the presence of ray C increases the exit pupil density.
  • the uncoupled light is reflected back out of the coupling grating 3 and partially out-coupled by diffraction.
  • the propagation direction of A in the waveguide sheet 1 is opposite, which just compensates the energy weakening of the light A when it is transmitted in the waveguide sheet 1, and improves the brightness uniformity of the outcoupled light in the entire visible area of the waveguide sheet.
  • this part of the light just compensates for the energy weakening of the light A when it is transmitted in the waveguide sheet 1, and improves the coupling out in the entire visible area of the waveguide sheet. Brightness uniformity of light.
  • the first reflection grating 4 needs to be disposed at the end of the coupling-out grating 3 along the light transmission direction.
  • the first reflection grating 4 is arranged on one side surface of the waveguide sheet 1, and the first reflection grating 4 is parallel to the groove line of the coupling-out grating 3.
  • the first reflection grating 4 The period of the out-coupling grating 3 is the same and the diffraction efficiency of the second-order diffracted light in the diffraction order is set to the maximum, or the first reflection grating 4 is half the period of the out-coupling grating 3 and the diffraction efficiency of the first-order diffracted light in the diffraction order is set.
  • the diffraction efficiency is set to the maximum, so that the light that passes through the coupling-out grating 3 but is not coupled out is returned to the coupling-out grating 3 by the first reflection grating 4, so as to be coupled out, thereby improving the overall light energy utilization rate of the waveguide assembly, Increases the exit pupil density of the waveguide assembly as a whole.
  • the light returned and recoupled by the first reflection grating 4 supplements the light that has been coupled out, the brightness uniformity of the light coupled out in the overall visible area of the waveguide sheet 1 is improved.
  • the fabrication process is simple, and the production is convenient.
  • the light that is not coupled out by the outcoupling grating 3 for the first time can be returned to the outcoupling grating 3 only by passing through a first reflection grating 4, and the utilization rate of light energy is higher.
  • the first reflection grating 4 borders the outcoupling grating 3 , and since the first reflection grating 4 and the coupling out grating 3 are arranged on the same side of the waveguide sheet 1 , the waveguide assembly is simple and convenient to manufacture. In other embodiments, there is a gap between the first reflection grating 4 and the coupling-out grating 3 , which is not specifically limited herein.
  • the width of the first reflection grating 4 is greater than 3 mm, and the reflection efficiency is high.
  • the first reflection grating 4 is a sinusoidal grating, a rectangular grating, a blazed grating, or an inclined grating inclined toward the direction of the coupling-out grating 3, and the groove depth is 400-600 nm.
  • the first reflection grating 4 may be a slanted grating or a blazed grating. Compared with a conventional rectangular grating, the slanted or blazed grating can concentrate the diffraction energy on a certain order, improving the first The reflection efficiency of the sub-reflection grating 4 is improved, thereby improving the utilization rate of light energy of the waveguide sheet 1 .
  • FIG. 4 is a diagram of a simulation result of light diffraction of a waveguide assembly provided by an embodiment of the present application.
  • the period of the first reflection grating 4 is 340 nm
  • the height is 500 nm
  • the duty cycle is 0.74
  • the inclination angle between the first reflection grating 4 and the horizontal direction is 66.7°
  • the first reflection grating 4 and the horizontal direction are 66.7°.
  • the refractive index of the waveguide sheet is all set to 1.7
  • the wavelength of light is 460 nm.
  • the maximum diffraction efficiency can reach more than 95%, and the average is about 75%, which can significantly improve the energy utilization rate of the waveguide sheet 1 .
  • the first reflection grating 4 is an inclined grating inclined in the direction of the coupling-out grating 3, and the second-order diffraction light has a high diffraction efficiency.
  • the second-order diffraction efficiency is greater than 80%. .
  • the coupling-out grating 3 is a diffraction grating or a holographic grating.
  • the coupling-out grating 3 when it is a diffraction grating, it can be a rectangular grating, a blazed grating, an inclined grating, a sinusoidal grating or a holographic grating, and the groove depth is 50-200 nm.
  • the coupling-out grating 3 is set as an ordinary rectangular grating
  • the first reflection grating 4 is set as a tilted grating or a blazed grating, because the existence of the first reflection grating 4 greatly improves the light energy of the waveguide sheet 1 Therefore, the out-coupling grating 3 does not need to be set as an inclined grating with high diffraction efficiency (in the conventional scheme, due to the low diffraction efficiency of ordinary rectangular gratings, an inclined grating is selected as the out-coupling grating, but the high diffraction efficiency of the inclined grating causes the distance
  • the field of view close to the coupling-in area 2 has higher energy coupling-out, while the field of view far from the coupling-in area 2 has lower energy coupling-out, and the energy distribution will be uneven in the entire visible area.
  • the setting of the primary reflection grating 4 improves the utilization rate of light energy, and at the same time avoids uneven coupling and output of energy in different
  • the thickness of the waveguide sheet 1 is 0.3-2.5 mm
  • the material of the waveguide sheet 1 is an optical material transparent to visible light
  • the refractive index of the waveguide sheet 1 is 1.4-2.2.
  • the coupling-out grating 3 is a one-dimensional grating.
  • the outcoupling grating 3 is a two-dimensional grating, which should also be within the protection scope of the present application, which is not specifically limited here.
  • the outcoupling grating 3 is a two-dimensional grating, it may be composed of two one-dimensional gratings disposed on both sides of the waveguide sheet 1 respectively or composed of two one-dimensional gratings disposed on one side of the waveguide sheet 1 superimposed.
  • the coupling region 2 includes a coupling grating 21 , and the coupling grating 21 is used for coupling light into the waveguide sheet 1 .
  • the coupled-in grating 21 is a rectangular grating, a blazed grating, a tilted grating, a sinusoidal grating or a holographic grating, with a period of 300-600 nm and a groove depth of 40-500 nm.
  • the coupling region 2 also includes a turning grating 22, which is used to diffuse and transmit the light coupled from the coupling grating 21 in the waveguide sheet 1.
  • the additional turning grating 22 can further increase the utilization rate of light energy.
  • the turning grating 22 is a rectangular grating, a blazed grating, a tilted grating, a sinusoidal grating or a holographic grating, with a period of 300-600 nm and a groove depth of 40-500 nm.
  • FIG. 5 is a schematic diagram of the waveguide assembly with grating vector shown in FIG. 1 .
  • the coupling grating 21 has a grating vector G0a
  • the turning grating 22 has a grating vector G0b
  • the first reflection grating 4 parallel to the groove line of the outcoupling grating 3 , so that the uncoupled light B is reflected by the first reflection grating 4 back to the outcoupling grating 3 .
  • the diffraction efficiency of the second-order diffracted light is set to be the largest among the diffraction orders; or the period of the first reflection grating 4 is When coupling out half of the period of the grating 3, among its diffraction orders, the diffraction efficiency of the first-order diffracted light is set to the maximum, so that the grating corresponding to the second-order diffracted light when the light B is diffracted at the first reflection grating 4
  • the uncoupled light is reflected back out of the coupling grating 3 and partially out-coupled by diffraction.
  • the propagation direction of A in the waveguide sheet 1 is opposite, which just compensates the energy weakening of the light A when it is transmitted in the waveguide sheet 1, and improves the brightness uniformity of the outcoupled light in the entire visible area of the waveguide sheet.
  • the coupling-in region 2 and the coupling-out grating 3 are located on the same surface of the waveguide sheet 1 . In other embodiments, the coupling-in region 2 and the coupling-out grating 3 are respectively located on two surfaces of the waveguide sheet 1 opposite to each other, which are not specifically limited herein.
  • the coupling-out grating 3 is a one-dimensional grating.
  • the outcoupling grating 3 is a two-dimensional grating, which should also be within the protection scope of the present application, which is not specifically limited here.
  • the outcoupling grating 3 is a two-dimensional grating, it may be composed of two one-dimensional gratings disposed on both sides of the waveguide sheet 1 respectively or composed of two one-dimensional gratings disposed on one side of the waveguide sheet 1 superimposed.
  • the coupling-out grating 3 is a rectangular grating, a blazed grating, an inclined grating, a sinusoidal grating or a holographic grating, and the groove depth is 50-200 nm.
  • FIG. 6 is a schematic structural diagram of a waveguide assembly provided by an embodiment of the present application.
  • the first reflection grating 4 includes a first reflection grating 41 and a second reflection grating 42 which are arranged in phase separation, and the grating vector sum of the first reflection grating 41 and the second reflection grating 42 for G2.
  • the coupling-in region 2 includes a coupling-in grating 21 and a turning grating 22 .
  • the coupling-in grating 21 has a grating vector G0a
  • the grating vector of the coupling-out grating 3 is G1.
  • the diffraction efficiency of the second-order diffracted light is set to the maximum; or the period of the first reflection grating 41 and the second reflection grating 42 is half of the period of the coupling-out grating 3, and among the diffraction orders, the first order
  • the first reflection grating 4 is set as two separate reflection gratings, which can reflect light from multiple directions, avoid omission, further improve the utilization rate of light energy, increase the exit pupil density, and increase the brightness uniformity .
  • the coupling-out grating 3 is a one-dimensional grating.
  • the outcoupling grating 3 is a two-dimensional grating, which should also be within the protection scope of the present application, which is not specifically limited here.
  • the outcoupling grating 3 is a two-dimensional grating, it may be composed of two one-dimensional gratings disposed on both sides of the waveguide sheet 1 respectively or composed of two one-dimensional gratings disposed on one side of the waveguide sheet 1 superimposed.
  • the coupling-out grating 3 is a rectangular grating, a blazed grating, an inclined grating, a sinusoidal grating or a holographic grating, and the groove depth is 50-200 nm.
  • the thickness of the waveguide sheet 1 is 0.3-2.5 mm
  • the material of the waveguide sheet 1 is an optical material transparent to visible light
  • the refractive index of the waveguide sheet 1 is 1.4-2.2.
  • the coupling region 2 may only have the coupling grating 21 without the turning grating 22 .
  • FIG. 7 is a schematic structural diagram of a waveguide assembly provided by an embodiment of the present application.
  • the waveguide assembly provided in this embodiment further includes a second reflection grating 5 , and the second reflection grating 5 and the first reflection grating 4 are provided on the same surface of the waveguide sheet 1 .
  • the second reflection grating 5 is disposed opposite to the first reflection grating 4 and located on both sides of the coupling-out grating 3 respectively.
  • the groove lines of the second reflection grating 5 are parallel to the groove lines of the outcoupling grating 3, the period of the second reflection grating 5 is the same as that of the coupling out grating 3, and the diffraction efficiency of the second order diffracted light in the diffraction order is set as
  • the period of the maximum, or second, reflection grating 5 is half the period of the outcoupling grating 3 and the diffraction efficiency of the first-order diffracted light in the diffraction order is set to be maximum.
  • the uncoupled light after being reflected by the first reflection grating 4 is transmitted to the second reflection grating 5 , and is reflected back out of the coupling grating 3 by the second reflection grating 5 and then coupled out.
  • the coupling-in region 2 includes a coupling-in grating 21 and a turning grating 22 .
  • the grating vector sum of the coupling-in grating 21 and the turning grating 22 is equal to G0 described in the previous embodiment
  • the first reflection grating 4 has a grating vector G1
  • the waveguide assembly provided in this embodiment is provided with a second reflection grating 5 on the waveguide sheet 1 , and the second reflection grating 5 and the first reflection grating 4 are located on the same side of the waveguide sheet 1 , and the second reflection grating 5
  • the groove line of the coupling-out grating 3 is parallel to the groove line of the coupling-out grating 3
  • the period of the second reflection grating 5 is the same as the period of the coupling-out grating 3 and the diffraction efficiency of the second-order diffracted light in the diffraction order is set to the maximum, or the second time
  • the period of the reflection grating 5 is half of the period of the outcoupling grating 3 and the diffraction efficiency of the first-order diffracted light in the diffraction order is set to the maximum, so that the light that is not coupled out by the outcoupling grating 3 is reflected back by the first reflection grating 41 After the grating 3 is coupled out, the light that
  • the second reflection grating 5 is a sinusoidal grating, a rectangular grating, a blazed grating, or an inclined grating inclined toward the direction of the coupling-out grating 3 .
  • the second reflection grating 5 is an inclined grating, and at this time, the diffraction efficiency is high (may exceed 80%).
  • the second reflection grating 5 is inclined toward the coupling-out grating 3 , which further improves the reflection efficiency of the second reflection grating 5 .
  • the coupling-out grating 3 is a one-dimensional grating.
  • the outcoupling grating 3 is a two-dimensional grating, which should also be within the protection scope of the present application, which is not specifically limited here.
  • the outcoupling grating 3 is a two-dimensional grating, it may be composed of two one-dimensional gratings disposed on both sides of the waveguide sheet 1 respectively or composed of two one-dimensional gratings disposed on one side of the waveguide sheet 1 superimposed.
  • the coupling-out grating 3 is a rectangular grating, a blazed grating, an inclined grating, a sinusoidal grating or a holographic grating, and the groove depth is 50-200 nm.
  • the thickness of the waveguide sheet 1 is 0.3-2.5 mm
  • the material of the waveguide sheet 1 is an optical material transparent to visible light
  • the refractive index of the waveguide sheet 1 is 1.4-2.2.
  • the coupling region 2 may only have the coupling grating 21 without the turning grating 22 .
  • FIG. 8 is a schematic structural diagram of a waveguide assembly provided by an embodiment of the present application.
  • the first reflection grating 4 includes a first reflection grating 41 and a second reflection grating 42 arranged in phase separation
  • the second reflection grating 5 includes a third reflection grating arranged in phase separation 51 and the fourth reflection grating 52
  • the first reflection grating 41 and the third reflection grating 51 are arranged oppositely
  • the second reflection grating 42 and the fourth reflection grating 52 are arranged oppositely, that is, the first reflection grating 41, the second reflection
  • the three reflection gratings 51 and the fourth reflection grating 52 are arranged sequentially around the coupling-in region 2 and the coupling-out grating 3 .
  • the periods of the first reflection grating 41 and the second reflection grating 42 are equal to the period in the vertical direction of the outcoupling grating 3 , and the diffraction efficiency of the second-order diffracted light is set to be the maximum, which can reach more than 80% after optimization.
  • the period of the third reflection grating 51 and the fourth reflection grating 52 is equal to the period of the outcoupling grating 3 in the horizontal direction, and the diffraction efficiency of the second-order diffracted light is set to the maximum value, which can reach more than 80% after optimization, so that the uncoupled light is not coupled out.
  • the period of the first reflection grating 41, the second reflection grating 42, the period of the third reflection grating 51 and the fourth reflection grating 52 can also be set to be half of the period of the coupling-out grating 3, corresponding to the diffraction
  • the diffraction efficiency of the first-order diffracted light in the order is set to be the maximum.
  • the first reflection grating 4 is set as two separate reflection gratings (41, 42), and the second reflection grating 5 is set as two separate reflection gratings (51, 52),
  • the first reflection grating 4 is set as two separate reflection gratings (41, 42)
  • the second reflection grating 5 is set as two separate reflection gratings (51, 52)
  • the coupling-out grating 3 is a two-dimensional grating.
  • the outcoupling grating 3 may be composed of two one-dimensional gratings disposed on both sides of the waveguide sheet 1 respectively or composed of two one-dimensional gratings disposed on one side of the waveguide sheet 1 superposed.
  • the coupling-out grating 3 may also be a one-dimensional grating, which is not specifically limited herein.
  • the coupling-in region 2 only includes the coupling-in grating 21 .
  • the coupling-in region may further include coupling-in gratings 21 and turning gratings 22 .
  • the coupling-out grating 3 is a rectangular grating, a blazed grating, an inclined grating, a sinusoidal grating or a holographic grating, and the groove depth is 50-200 nm.
  • FIG. 9 is a side view of a portion of the waveguide assembly shown in FIG. 8 .
  • the outcoupling grating 3 is a two-dimensional grating, and is composed of two one-dimensional gratings ( 31 , 32 ) respectively disposed on the two surfaces of the waveguide sheet 1 .
  • the light is coupled into the waveguide sheet 1 through the coupling-in region 2, and the light that is not coupled out by the two-dimensional coupling-out grating 3 (31, 32) is reflected by the first reflection grating 4 (or 41), and then passes through the two-dimensional coupling.
  • the output grating 3 (31, 32) is coupled out.
  • FIG. 10 is a grating vector diagram of the waveguide assembly shown in FIG. 8 .
  • the coupling-in region 2 has a grating vector G0
  • the one-dimensional coupling-out grating 31 has a grating vector G1
  • the one-dimensional coupling-out grating 32 has a grating vector G2
  • the first reflection grating 4 (42) has a grating vector G3.
  • FIG. 11 is a grating vector diagram of the waveguide assembly shown in FIG. 8 .
  • the coupling-in region 2 has a grating vector G0
  • the one-dimensional coupling-out grating 31 has a grating vector G1
  • the one-dimensional coupling-out grating 32 has a grating vector G2
  • the first reflection grating 4 (42) has a grating vector G3
  • the second reflection grating 5 has a grating vector G4
  • the light that has not been coupled out after reflection is transmitted to the secondary reflection grating 5 (52), and is reflected back to the outcoupling grating 3 (31, 32) by the second reflection grating 5 (52) and coupled out, improving the light energy utilization, increased exit pupil density, and increased brightness uniformity.
  • FIG. 12 is a grating vector diagram of the waveguide assembly shown in FIG. 8 .
  • the coupling-in region 2 has a grating vector G0
  • the one-dimensional coupling-out grating 31 has a grating vector G1
  • the first reflection grating 4 (41) has a grating vector G2
  • the first reflection grating 4 ( 41 ) is then coupled out by the coupling-out grating 31 , which improves the utilization rate of light energy, increases the exit pupil density, and increases the brightness uniformity.
  • FIG. 13 is a grating vector diagram of the waveguide assembly shown in FIG. 8 .
  • the coupling-in region 2 has a grating vector G0
  • the one-dimensional coupling-out grating 32 has a grating vector G1
  • the second reflection grating 5 (51) has a grating vector G2
  • the second reflection grating 5 (51) is then coupled out by the outcoupling grating 32, which improves the utilization rate of light energy, increases the exit pupil density, and increases the brightness uniformity.
  • the included angle between the two one-dimensional gratings of the coupling-out grating 3 is 50-70 degrees.
  • the coupling-out grating 3 is a rectangular grating, a blazed grating, an inclined grating, a sinusoidal grating or a holographic grating, and the groove depth is 50-200 nm.
  • the coupling-out grating 3 is formed by superposing two one-dimensional gratings disposed on the same surface of the waveguide sheet 1 .
  • the thickness of the waveguide sheet 1 is 0.3-2.5 mm
  • the material of the waveguide sheet 1 is an optical material transparent to visible light
  • the refractive index of the waveguide sheet 1 is 1.4-2.2.
  • FIG. 14 is a schematic structural diagram of a near-eye display device according to an embodiment of the present application.
  • an embodiment of the present application further provides a near-eye display device, including a projector 6 and a waveguide assembly, where the waveguide assembly is the waveguide assembly described in any of the foregoing embodiments.
  • the waveguide assembly includes:
  • Waveguide sheet 1
  • the coupling-in region 2 is arranged on a surface of the waveguide sheet 1, and the coupling-in region 2 is used to couple light into the waveguide sheet 1 and make the light diffuse and transmit in the waveguide sheet 1;
  • the coupling-out grating 3 is arranged on a surface of the waveguide sheet 1, and the coupling-out grating 3 is used for coupling the light coupled in from the coupling-in region 2 out of the waveguide sheet 1;
  • the first reflection grating 4 is arranged on the same surface of the waveguide plate 1 as the outcoupling grating 3 and is located at the end of the outcoupling grating 3 along the light transmission direction.
  • the first reflection grating 4 is parallel to the groove lines of the outcoupling grating 3 , the period of the first reflection grating 4 and the outcoupling grating 3 is the same and the diffraction efficiency of the second-order diffracted light in the diffraction order is set to the maximum, or the first reflection grating 4 is half the period of the coupling out grating 3 and the diffraction order
  • the diffraction efficiency of the first-order diffracted light in the second time is set to be the maximum, and the first-time reflection grating 4 is used to reflect the light passing through the out-coupling grating 3 but not out-coupled back to the out-coupling grating 3 and then out-coupling.
  • the light emitted by the projector 6 is coupled into the waveguide sheet 1 by the coupling-in region 2 , and diffuses in the waveguide sheet 1 to be transmitted to the coupling-out grating 3 .
  • the outcoupling grating 3 couples the light A out of the waveguide sheet 1 and is observed by the human eye, thereby forming a visible area.
  • the uncoupled light B will continue to propagate to the first reflection grating 4, the first reflection grating 4 will reflect the light B back out of the coupling grating 3, and then coupled out by the coupling out grating 3, that is, the light C, Ray C remains parallel to ray A.
  • the near-eye display device includes a projector 6 and a waveguide assembly, and the waveguide assembly is provided with a first reflection grating 4 on one side surface of the waveguide sheet 1, and makes the first reflection grating 4 and the coupling-out grating 3
  • the groove lines are parallel, the period of the first reflection grating 4 and the outcoupling grating 3 are the same, and the diffraction efficiency of the second-order diffracted light in the diffraction order is set to the maximum, or the first reflection grating 4 is the outcoupling grating 3 period.
  • Half and the diffraction efficiency of the first-order diffracted light in the diffraction order is set to the maximum, so that the light that passes through the coupling-out grating 3 but is not coupled out is returned to the coupling-out grating 3 by the first reflection grating 4, so as to be coupled out, thereby
  • the utilization rate of light energy of the entire waveguide assembly is improved, and the exit pupil density of the entire waveguide assembly is increased.
  • the light returned and recoupled by the first reflection grating 4 supplements the light that has been coupled out, the brightness uniformity of the light coupled out in the overall visible area of the waveguide sheet 1 is improved.
  • the fabrication process is simple, and the production is convenient.
  • the light that is not coupled out of the outcoupling grating 3 for the first time can be returned to the outcoupling grating 3 only by passing through a first reflection grating 4, and the utilization rate of light energy is higher.
  • FIG. 15 is a schematic structural diagram of a near-eye display device according to an embodiment of the present application.
  • the waveguide assembly further includes a second reflection grating 5 , and the second reflection grating 5 and the first reflection grating 4 are disposed on the same surface of the waveguide sheet 1 .
  • the second reflection grating 5 is disposed opposite to the first reflection grating 4 and located on both sides of the coupling-out grating 3 respectively.
  • the groove lines of the second reflection grating 5 are parallel to the groove lines of the outcoupling grating 3, the period of the second reflection grating 5 is the same as that of the coupling out grating 3, and the diffraction efficiency of the second order diffracted light in the diffraction order is set as
  • the period of the maximum, or second, reflection grating 5 is half the period of the outcoupling grating 3 and the diffraction efficiency of the first-order diffracted light in the diffraction order is set to be maximum.
  • the uncoupled light after being reflected by the first reflection grating 4 is transmitted to the second reflection grating 5 , and is reflected back out of the coupling grating 3 by the second reflection grating 5 and then coupled out.
  • the light emitted by the projector 6 is coupled into the waveguide sheet 1 by the coupling-in region 2 , and diffuses in the waveguide sheet 1 to be transmitted to the coupling-out grating 3 .
  • the coupling-out grating 3 couples the light A to the outside of the waveguide sheet 1, thereby forming a visible area.
  • the uncoupled light B will continue to propagate to the first reflection grating 4, the first reflection grating 4 will reflect the light B back out of the coupling grating 3, and then coupled out by the coupling out grating 3, that is, the light C, Ray C remains parallel to ray A.
  • the second reflection grating 5 is disposed on the waveguide sheet 1 in the waveguide assembly, and the second reflection grating 5 and the first reflection grating 4 are located on the same side of the waveguide sheet 1, and
  • the groove lines of the second reflection grating 5 are parallel to the groove lines of the outcoupling grating 3, the period of the second reflection grating 5 is the same as that of the coupling out grating 3, and the diffraction efficiency of the second order diffracted light in the diffraction order is set as Maximum, or the period of the second reflection grating 5 is half of the period of the coupling-out grating 3 and the diffraction efficiency of the first-order diffracted light in the diffraction order is set to the maximum, so that the light that is not coupled out by the coupling-out grating 3 is absorbed by the first order.
  • the uncoupled light is then reflected back out of the grating 3 through the second reflection grating 5, thereby further improving the utilization rate of light energy, increasing the exit pupil density, Improved brightness uniformity.
  • connection should be understood in a broad sense unless otherwise expressly specified and limited. For example, it may be a fixed connection or a detachable connection. Connection, or integral connection; may be mechanical connection or electrical connection; may be direct communication, or indirect communication through an intermediate medium, and may be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations. Also, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

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Abstract

一种波导组件，包括：波导片；耦入区域，设于波导片的一表面上，耦入区域用于将光线耦入；耦出光栅，设于波导片的一表面上，耦出光栅用于将从耦入区域耦入的光线耦出波导片；和第一次反射光栅，与耦出光栅设于波导片的同一表面上并位于耦出光栅沿光线传输方向上的末端，第一次反射光栅与耦出光栅的槽线平行，第一次反射光栅与耦出光栅的周期相同且衍射级次中二阶衍射光的衍射效率被设置为最大，或第一次反射光栅为耦出光栅周期的一半且衍射级次中一阶衍射光的衍射效率被设置为最大，第一次反射光栅用于将经过耦出光栅而未耦出的光线反射回耦出光栅再耦出，提高了光能利用率、出瞳密度、亮度均匀性，制作工艺简单。

Description

波导组件和包括波导组件的近眼显示设备 技术领域
本申请涉及光学传输技术领域，具体地涉及一种波导组件和包括波导组件的近眼显示设备。
背景技术
近眼显示设备主要是用于将图片或视频显示到人眼中，近眼显示设备可广泛应用于虚拟现实、增强现实、混合现实或军事等领域。
近眼显示设备包括光源组件和波导等部件，波导上设有耦入区域和耦出区域，光源组件发出的光由耦入区域耦入到波导内，光线再由耦出区域耦出波导传输至人眼。
但是由于在耦出区域，光的衍射效率很低，大部分光能被波导的侧边吸收或在波导的侧边处逃逸，造成波导整体光能利用率很低，进而导致近眼显示设备的出瞳密度很低。而且，由于光线在波导中传输时，能量是逐渐减弱的，导致了耦出的光线亮度不均匀。
发明内容
本申请的主要目的是提供一种光能利用率高、出瞳密度高、亮度均匀的波导组件和包括波导组件的近眼显示设备。
本申请一实施例提供一种波导组件，包括：
波导片；
耦入区域，设于所述波导片的一表面上，所述耦入区域用于将光线耦入到所述波导片内并使所述光线在所述波导片内扩散传输；
耦出光栅，设于所述波导片的一表面上，所述耦出光栅用于将从所述耦入区域耦入的光线耦出所述波导片；和
第一次反射光栅，与所述耦出光栅设于所述波导片的同一表面上并位于所述耦出光栅沿光线传输方向上的末端，所述第一次反射光栅与所述耦出光栅的槽线平行，所述第一次反射光栅与所述耦出光栅的周期相同且衍射级次中二阶衍射光的衍射效率被设置为最大，或所述第一次反射光栅为所述耦出光栅周期的一半且衍射级次中一阶衍射光的衍射效率被设置为最大，所述第一次反射光栅用于将经过所述耦出光栅而未耦出的光线反射回所述耦出光栅再耦出。
在一个实施例中，所述第一次反射光栅包括相分离设置的第一反射光栅和第二反射光栅。
在一个实施例中，所述第一次反射光栅为正弦光栅、矩形光栅、闪耀光栅或向所述耦出光栅的方向倾斜的倾斜光栅。
在一个实施例中，波导组件还包括第二次反射光栅，所述第二次反射光栅与所述第一次反射光栅设于所述波导片的同一表面上；
所述第二次反射光栅与所述第一次反射光栅相对设置并分别位于所述耦出光栅的两侧；
所述第二次反射光栅的槽线与所述耦出光栅的槽线平行，所述第二次反射光栅的周期与所述耦 出光栅的周期相同且衍射级次中二阶衍射光的衍射效率被设置为最大，或所述第二次反射光栅的周期为所述耦出光栅周期的一半且衍射级次中一阶衍射光的衍射效率被设置为最大；
经所述第一次反射光栅反射后未耦出的光线传输至所述第二次反射光栅处，由所述第二次反射光栅反射回所述耦出光栅。
在一个实施例中，所述第一次反射光栅包括相分离设置的第一反射光栅和第二反射光栅，所述第二次反射光栅包括相分离设置的第三反射光栅和第四反射光栅，所述第一反射光栅和所述第三反射光栅相对设置，所述第二反射光栅和所述第四反射光栅相对设置。
在一个实施例中，所述第二次反射光栅为正弦光栅、矩形光栅、闪耀光栅或向所述耦出光栅的方向倾斜的倾斜光栅。
在一个实施例中，所述耦出光栅为一维光栅。
在一个实施例中，所述耦出光栅由两个分别设于所述波导片两个表面上的一维光栅构成或由设在所述波导片同一表面的两个一维光栅叠加构成。
在一个实施例中，所述耦出光栅的两个一维光栅之间的夹角为50-70度。
在一个实施例中，所述耦出光栅为矩形光栅、闪耀光栅、倾斜光栅、正弦光栅或全息光栅，并槽深为50～200nm。
在一个实施例中，所述第一次反射光栅与所述耦出光栅相接壤。
在一个实施例中，所述第一次反射光栅的宽度大于3mm。
在一个实施例中，所述耦出光栅为矩形光栅，所述第一次反射光栅和/或所述第二次反射光栅为倾斜光栅或闪耀光栅。
在一个实施例中，所述耦入区域包括耦入光栅，所述耦入光栅用于将光线耦入到所述波导片内。
在一个实施例中，所述耦入光栅为矩形光栅、闪耀光栅、倾斜光栅、正弦光栅或全息光栅中，并周期为300～600nm、槽深为40～500nm。
在一个实施例中，所述耦入区域还包括转折光栅，所述转折光栅用于使从所述耦入光栅耦入的光线在所述波导片内扩散传输。
在一个实施例中，所述转折光栅为矩形光栅、闪耀光栅、倾斜光栅、正弦光栅或全息光栅中，并周期为300～600nm、槽深为40～500nm。
在一个实施例中，所述耦入区域与所述耦出光栅位于所述波导片的同一表面上或分别位于所述波导片相背的两个表面上。
在一个实施例中，所述波导片的厚度为0.3～2.5mm，所述波导片的材料为对可见光透明的光学材料，所述波导片的折射率为1.4～2.2。
本申请一实施例还提供一种近眼显示设备，包括投影光机和波导组件，所述波导组件为上述任一实施例所述的波导组件。
有益效果：
本申请提供的波导组件，在波导片的一侧表面上设置了第一次反射光栅，并使第一次反射光栅与耦出光栅的槽线平行，第一次反射光栅与耦出光栅的周期相同且衍射级次中二阶衍射光的衍射效 率被设置为最大，或第一次反射光栅为耦出光栅周期的一半且衍射级次中一阶衍射光的衍射效率被设置为最大，从而使得经过耦出光栅而未耦出的光线被第一次反射光栅返回耦出光栅，从而进行耦出，从而提高了波导组件整体的光能利用率、增加了波导组件整体的出瞳密度。且由于经第一次反射光栅返回再耦出的光线对原已耦出的光线进行了补充，从而提高了波导片整体可视区域内耦出的光线的亮度均匀性。而且，根据本发明的光学设计，只需要在波导片的一侧表面上设置第一次反射光栅，制作工艺简单，便于生产制造。而且本实施例提供的波导组件，第一次未被耦出光栅耦出的光线只用经过一个第一次反射光栅就可以返回耦出光栅处，光能利用率更高。
附图说明
本发明上述和/或附加方面的优点从结合下面附图对实施例的描述中将变得明显和容易理解，其中：
图1为本申请一实施例提供的波导组件的结构示意图；
图2为图1所示的波导组件的侧视图；
图3为图1所示的波导组件的光栅矢量图；
图4为本申请一实施例提供的波导组件的光衍射的仿真结果图；
图5为图1所示的波导组件带光栅矢量的示意图；
图6为本申请一实施例提供的波导组件的结构示意图；
图7为本申请一实施例提供的波导组件的结构示意图；
图8为本申请一实施例提供的波导组件的结构示意图；
图9为图8所示的波导组件一部分的侧视图；
图10为图8所示的波导组件的一光栅矢量图；
图11为图8所示的波导组件的一光栅矢量图；
图12为图8所示的波导组件的一光栅矢量图；
图13为图8所示的波导组件的一光栅矢量图；
图14为本申请一实施例提供的近眼显示设备的结构示意图；
图15为本申请一实施例提供的近眼显示设备的结构示意图。
其中，图1至图15中附图标记与部件名称之间的对应关系为：
1、波导片；2、耦入区域；21、耦入光栅；22、转折光栅；3、耦出光栅；4、第一次反射光栅；41、第一反射光栅；42、第二反射光栅；5、第二次反射光栅；51、第三反射光栅；52、第四反射光栅；6投影光机。
具体实施方式
为了能够更清楚地理解本发明的上述目的、特征和优点，下面结合附图和具体实施方式对本发明进行进一步的详细描述。需要说明的是，在不冲突的情况下，本申请的实施例及实施例中的特征可以相互组合。
实施例1
图1为本申请一实施例提供的波导组件的结构示意图。
如图1所示，本实施例提供的波导组件，包括：
波导片1；
耦入区域2，设于波导片1的一表面上，耦入区域2用于将光线耦入到波导片1内并使光线在波导片1内扩散传输；
耦出光栅3，设于波导片1的一表面上，耦出光栅3用于将从耦入区域2耦入的光线耦出波导片1；和
第一次反射光栅4，与耦出光栅3设于波导片1的同一表面上并位于耦出光栅3沿光线传输方向上的末端，第一次反射光栅4与耦出光栅3的槽线平行，第一次反射光栅4与耦出光栅3的周期相同且衍射级次中二阶衍射光的衍射效率被设置为最大，或第一次反射光栅4为耦出光栅3周期的一半且衍射级次中一阶衍射光的衍射效率被设置为最大，第一次反射光栅4用于将经过耦出光栅3而未耦出的光线反射回耦出光栅3再耦出。
图2为图1所示的波导组件的侧视图。
如图2所示，本实施例提供的波导组件的工作原理过程如下：
光线由耦入区域2耦入到波导片1内，并在波导片1内扩散传输至耦出光栅3。耦出光栅3将光线A耦出到波导片1外，从而被人眼观察到，即形成可视区域。而未被耦出的光线B会继续传播至第一次反射光栅4处，第一次反射光栅4将光线B反射回耦出光栅3，再由耦出光栅3耦出，即为光线C，光线C与光线A保持平行。
图3为图1所示的波导组件的光栅矢量图。
如图3所示，耦入区域2具有光栅矢量G0，耦出光栅3具有光栅矢量G1，第一次反射光栅4具有光栅矢量G2。由于第一次反射光栅4与耦出光栅3的槽线平行，从而使得第一次反射光栅4与耦出光栅3的光栅矢量相互平行，才使得未被耦出光线B被第一次反射光栅4反射回耦出光栅3处。而第一次反射光栅4的周期决定了其矢量大小。进而当第一次反射光栅4的周期与耦出光栅3的周期相同时，其衍射级次中，二阶衍射光的衍射效率被设置为最大，从而使得光线B在第一次反射光栅4处衍射时二阶衍射光所对应的光栅矢量大小是耦出光栅3矢量的两倍，进而使得光栅矢量G0+G1+G2＝0，最终使得光线C被耦出，进而提高了光能利用率，并且光线C的存在提高了出瞳密度。并且由于光线在波导片中传输时能量是逐渐减弱的，未耦出光线反射回耦出光栅3并部分被衍射耦出，这部分光线在传输时能量也是逐渐减弱的，其传播方向正好和光线A在波导片1内的传播方向相反，正好补偿了光线A在波导片1内传输时的能量减弱，提高了波导片整个可视区域内的耦出光线的亮度均匀性。
当第一次反射光栅4的周期为耦出光栅3的周期的一半时，其衍射级次中，一阶衍射光的衍射效率被设置为最大，故其矢量大小为耦出光栅3矢量大小的两倍，也使得光栅矢量G0+G1+G2＝0，也能将光线C耦出，提高光能利用率，并且光线C的存在提高了出瞳密度。并且由于未耦出光线反射回耦出光栅3并部分被衍射耦出，这部分光线正好补偿了光线A在波导片1内传输时的能量减弱， 提高了波导片整个可视区域内的耦出光线的亮度均匀性。
在本实施例中，由于未被耦出光线在波导片1内全反射传输，故第一次反射光栅4需要设置在耦出光栅3沿光线传输方向的末端。
本实施例提供的波导组件，在波导片1的一侧表面上设置了第一次反射光栅4，并使第一次反射光栅4与耦出光栅3的槽线平行，第一次反射光栅4与耦出光栅3的周期相同且衍射级次中二阶衍射光的衍射效率被设置为最大，或第一次反射光栅4为耦出光栅3周期的一半且衍射级次中一阶衍射光的衍射效率被设置为最大，从而使得经过耦出光栅3而未耦出的光线被第一次反射光栅4返回耦出光栅3，从而进行耦出，从而提高了波导组件整体的光能利用率、增加了波导组件整体的出瞳密度。且由于经第一次反射光栅4返回再耦出的光线对原已耦出的光线进行了补充，从而提高了波导片1整体可视区域内耦出的光线的亮度均匀性。而且，根据本发明的光学设计，只需要在波导片1的一侧表面上设置第一次反射光栅4，制作工艺简单，便于生产制造。而且本实施例提供的波导组件，第一次未被耦出光栅3耦出的光线只用经过一个第一次反射光栅4就可以返回耦出光栅3处，光能利用率更高。
进一步地，第一次反射光栅4与耦出光栅3相接壤，再加上由于第一次反射光栅4与耦出光栅3设于波导片1的同一侧，从而使得波导组件制作简单方便。在其他实施例中，第一次反射光栅4与耦出光栅3之间具有间隙，在此不做具体限定。
在本实施例中，第一次反射光栅4的宽度大于3mm，反射效率高。
在本实施例中，第一次反射光栅4为正弦光栅、矩形光栅、闪耀光栅或向耦出光栅3的方向倾斜的倾斜光栅，且槽深为400～600nm。在一些优选的实施例中，第一反射光栅4可以是倾斜光栅或者闪耀光栅，相对于常规的矩形光栅，设置为倾斜光栅或者闪耀光栅可以将衍射能量集中在某一级次上，提升第一次反射光栅4的反射效率，从而提高了波导片1的光能利用率。
图4为本申请一实施例提供的波导组件的光衍射的仿真结果图。
如图4所示，以第一次反射光栅4以周期为340nm，高度为500nm，占空比为0.74，第一次反射光栅4与水平方向的倾角为66.7°，第一次反射光栅4与波导片的折射率均设为1.7，光的波长为460nm为例，其最高衍射效率可以达到95％以上，平均达到75％左右，能够显著提高波导片1的能量利用率。
进一步优选地，第一次反射光栅4为向耦出光栅3的方向倾斜的倾斜光栅，此时二阶衍射光线具有较高的衍射效率，在一些实施例中，其二阶衍射效率大于80％。
在本实施例中，耦出光栅3为衍射光栅或全息光栅。其中，当耦出光栅3为衍射光栅时，可以为矩形光栅、闪耀光栅、倾斜光栅、正弦光栅或全息光栅，并槽深为50～200nm。
在一个优选的实施例中，耦出光栅3设置为普通矩形光栅，第一次反射光栅4设置为倾斜光栅或者闪耀光栅，由于第一次反射光栅4的存在大大提升了波导片1的光能利用率，所以耦出光栅3不需要设置为衍射效率较高的倾斜光栅(常规方案中由于普通矩形光栅衍射效率低下，故会选择倾斜光栅作为耦出光栅，但倾斜光栅衍射效率较高导致距离耦入区域2近的视场具有较高能量耦出，而距离耦入区域2远的视场具有较低能量耦出，到时在整个可视区域内能量分布不均)，本方案通过 第一次反射光栅4的设置提升了光能利用率，同时避免了不同视场内耦出能量不均。
在本实施例中，波导片1的厚度为0.3～2.5mm，波导片1的材料为对可见光透明的光学材料，波导片1的折射率为1.4～2.2。
在本实施例中，耦出光栅3为一维光栅。根据本领域技术人员容易得知，在其他实施例中，耦出光栅3为二维光栅，应当也在本申请的保护范围内，在此不做具体限定。当耦出光栅3为二维光栅时，可以为由分别设置于波导片1两侧的两个一维光栅构成或者由设于波导片1一侧的两个一维光栅叠加构成。
实施例2
在本实施例中，如图1所示，耦入区域2包括耦入光栅21，耦入光栅21用于将光线耦入到波导片1内。耦入光栅21为矩形光栅、闪耀光栅、倾斜光栅、正弦光栅或全息光栅中，并周期为300～600nm、槽深为40～500nm。
进一步地，耦入区域2还包括转折光栅22，转折光栅22用于使从耦入光栅21耦入的光线在波导片1内扩散传输，增设转折光栅22可以进一步增加光能利用率。更进一步地，转折光栅22为矩形光栅、闪耀光栅、倾斜光栅、正弦光栅或全息光栅中，并周期为300～600nm、槽深为40～500nm。
图5为图1所示的波导组件带光栅矢量的示意图。
在本实施例中，如图5所示，耦入光栅21具有光栅矢量G0a，转折光栅22具有光栅矢量G0b，且耦入光栅21和转折光栅22的矢量和等于耦入区域2的光栅矢量G0，即G0a+G0b＝G0。而又保持第一次反射光栅4与耦出光栅3的槽线平行，使得未被耦出光线B被第一次反射光栅4反射回耦出光栅3处。而又使第一次反射光栅4的周期与耦出光栅3的周期相同时，其衍射级次中，二阶衍射光的衍射效率被设置为最大；或使第一次反射光栅4的周期为耦出光栅3的周期的一半时，其衍射级次中，一阶衍射光的衍射效率被设置为最大，从而使得光线B在第一次反射光栅4处衍射时二阶衍射光所对应的光栅矢量大小是耦出光栅3矢量的两倍，进而使得光栅矢量G0+G1+G2＝0，最终使得光线C被耦出，进而提高了光能利用率，并且光线C的存在提高了出瞳密度。并且由于光线在波导片中传输时能量是逐渐减弱的，未耦出光线反射回耦出光栅3并部分被衍射耦出，这部分光线在传输时能量也是逐渐减弱的，其传播方向正好和光线A在波导片1内的传播方向相反，正好补偿了光线A在波导片1内传输时的能量减弱，提高了波导片整个可视区域内的耦出光线的亮度均匀性。
在本实施例中，耦入区域2与耦出光栅3位于波导片1的同一表面上。在其他实施例中，耦入区域2与耦出光栅3分别位于波导片1相背的两个表面上，在此不做具体限定。
在本实施例中，耦出光栅3为一维光栅。根据本领域技术人员容易得知，在其他实施例中，耦出光栅3为二维光栅，应当也在本申请的保护范围内，在此不做具体限定。当耦出光栅3为二维光栅时，可以为由分别设置于波导片1两侧的两个一维光栅构成或者由设于波导片1一侧的两个一维光栅叠加构成。
在本实施例中，耦出光栅3为矩形光栅、闪耀光栅、倾斜光栅、正弦光栅或全息光栅，并槽深为50～200nm。
实施例3
图6为本申请一实施例提供的波导组件的结构示意图。
如图6所示，在本实施例中，第一次反射光栅4包括相分离设置的第一反射光栅41和第二反射光栅42，第一反射光栅41和第二反射光栅42的光栅矢量和为G2。
在本实施例中，耦入区域2包括耦入光栅21和转折光栅22。
耦入光栅21具有光栅矢量G0a，转折光栅22具有光栅矢量G0b，而且使得G0a+G0b＝G0。
耦出光栅3的光栅矢量为G1。
而由于第一反射光栅41和第二反射光栅42的槽线均与耦出光栅3的槽线平行，且第一反射光栅41和第二反射光栅42的周期与耦出光栅3的周期相同，其衍射级次中，二阶衍射光的衍射效率被设置为最大；或第一反射光栅41和第二反射光栅42的周期为耦出光栅3的周期的一半，其衍射级次中，一阶衍射光的衍射效率被设置为最大，从而使得G0+G1+G2＝0，最终使得光线C被耦出，进而提高了光能利用率、出瞳密度以及亮度均匀性。
本实施例提供的波导组件将第一次反射光栅4设置为两个分离结构的反射光栅，可以从多方位反射光线，避免遗漏，进一步提高光能利用率、增加出瞳密度以及增加亮度均匀性。
在本实施例中，耦出光栅3为一维光栅。根据本领域技术人员容易得知，在其他实施例中，耦出光栅3为二维光栅，应当也在本申请的保护范围内，在此不做具体限定。当耦出光栅3为二维光栅时，可以为由分别设置于波导片1两侧的两个一维光栅构成或者由设于波导片1一侧的两个一维光栅叠加构成。
在本实施例中，耦出光栅3为矩形光栅、闪耀光栅、倾斜光栅、正弦光栅或全息光栅，并槽深为50～200nm。
在本实施例中，波导片1的厚度为0.3～2.5mm，波导片1的材料为对可见光透明的光学材料，波导片1的折射率为1.4～2.2。
在其他实施例中，耦入区域2可以仅只有耦入光栅21，没有转折光栅22。
实施例4
图7为本申请一实施例提供的波导组件的结构示意图。
如图7所示，本实施例提供的波导组件还包括第二次反射光栅5，第二次反射光栅5与第一次反射光栅4设于波导片1的同一表面上。
第二次反射光栅5与第一次反射光栅4相对设置并分别位于耦出光栅3的两侧。
第二次反射光栅5的槽线与耦出光栅3的槽线平行，第二次反射光栅5的周期与耦出光栅3的周期相同且衍射级次中二阶衍射光的衍射效率被设置为最大，或第二次反射光栅5的周期为耦出光栅3周期的一半且衍射级次中一阶衍射光的衍射效率被设置为最大。
经第一次反射光栅4反射后未耦出的光线传输至第二次反射光栅5处，由第二次反射光栅5反射回耦出光栅3再耦出。
在本实施例中，耦入区域2包括耦入光栅21和转折光栅22。
耦入光栅21和转折光栅22的光栅矢量和等于前述实施例所述的G0，第一次反射光栅4具有光栅矢量G1，耦出光栅3和第二次反射光栅5的光栅矢量和为G2。由于第一次反射光栅4和第二次 反射光栅5的槽线设置、周期设置及衍射级次设置，从而使得G0+G1+G2＝0，最终使得光线经由第一次反射光栅4反射后被耦出或经由第二次反射光栅5反射后被耦出，进而提高了光能利用率、出瞳密度以及亮度均匀性。
本实施例提供的波导组件在波导片1上设置了第二次反射光栅5，且第二次反射光栅5与第一次反射光栅4位于波导片1的同一侧，且第二次反射光栅5的槽线与耦出光栅3的槽线平行，第二次反射光栅5的周期与耦出光栅3的周期相同且衍射级次中二阶衍射光的衍射效率被设置为最大，或第二次反射光栅5的周期为耦出光栅3周期的一半且衍射级次中一阶衍射光的衍射效率被设置为最大，从而使得经耦出光栅3未耦出的光线被第一反射光栅41反射回耦出光栅3后，仍未耦出的光线再经由第二次反射光栅5反射回耦出光栅3耦出，从而进一步提高了光能利用率、增加了出瞳密度、提高了亮度均匀性。
在本实施例中，第二次反射光栅5为正弦光栅、矩形光栅、闪耀光栅或向耦出光栅3的方向倾斜的倾斜光栅。优选地，第二次反射光栅5为倾斜光栅，此时衍射效率高(可超过80％)。更进一步地，第二次反射光栅5朝向耦出光栅3倾斜，进一步提高第二次反射光栅5的反射效率。
在本实施例中，耦出光栅3为一维光栅。根据本领域技术人员容易得知，在其他实施例中，耦出光栅3为二维光栅，应当也在本申请的保护范围内，在此不做具体限定。当耦出光栅3为二维光栅时，可以为由分别设置于波导片1两侧的两个一维光栅构成或者由设于波导片1一侧的两个一维光栅叠加构成。
在本实施例中，耦出光栅3为矩形光栅、闪耀光栅、倾斜光栅、正弦光栅或全息光栅，并槽深为50～200nm。
在本实施例中，波导片1的厚度为0.3～2.5mm，波导片1的材料为对可见光透明的光学材料，波导片1的折射率为1.4～2.2。
在其他实施例中，耦入区域2可以仅只有耦入光栅21，没有转折光栅22。
实施例5
图8为本申请一实施例提供的波导组件的结构示意图。
在本实施例中，如图8所示，第一次反射光栅4包括相分离设置的第一反射光栅41和第二反射光栅42，第二次反射光栅5包括相分离设置的第三反射光栅51和第四反射光栅52，第一反射光栅41和第三反射光栅51相对设置，第二反射光栅42和第四反射光栅52相对设置，即第一反射光栅41、第二反射光栅42、第三反射光栅51和第四反射光栅52依次围绕耦入区域2和耦出光栅3设置。
第一反射光栅41和第二反射光栅42的周期等于耦出光栅3垂直方向的周期，其二阶衍射光的衍射效率被设置为最大，经过优化可以达到80％以上。第三反射光栅51和第四反射光栅52的周期等于耦出光栅3水平方向的周期，其二阶衍射光的衍射效率被设置为最大，经过优化可以达到80％以上，使得未被耦出光线能在相对的反射光栅(41、51或42、52)中来回传输，提高了波导片1的光能利用率、出瞳密度以及亮度均匀性。可以理解的是，第一反射光栅41、第二反射光栅42的周期、第三反射光栅51和第四反射光栅52的周期也可以设置为是耦出光栅3的周期的一半，对应的其衍射级次中一阶衍射光的衍射效率被设置为最大。
本实施例提供的波导组件通过将第一次反射光栅4设置为两个分离的反射光栅(41、42)，将第二次反射光栅5设置为两个分离的反射光栅(51、52)，从而使得能够从多方位反射回光线，并能够在多个反射光栅之间来回传输(41和51之间或42和52之间)，从而提高了光能利用率、出瞳密度和亮度均匀性。
在本实施例中，耦出光栅3为二维光栅。具体地，当耦出光栅3可以为由分别设置于波导片1两侧的两个一维光栅构成或者由设于波导片1一侧的两个一维光栅叠加构成。在其他实施例中，耦出光栅3也可以为一维光栅，在此不做具体限定。
在本实施例中，耦入区域2仅包括耦入光栅21。在其他实施例中，耦入区域还可以包括耦入光栅21和转折光栅22。
在本实施例中，耦出光栅3为矩形光栅、闪耀光栅、倾斜光栅、正弦光栅或全息光栅，并槽深为50～200nm。
实施例6
图9为图8所示的波导组件一部分的侧视图。
在本实施例中，如图9所示，耦出光栅3为二维光栅，且为由两个分别设于波导片1两个表面上的一维光栅(31、32)构成。
光线经耦入区域2耦入波导片1内，未被二维耦出光栅3(31、32)耦出的光线，被第一次反射光栅4(或41)反射后，再经二维耦出光栅3(31、32)耦出。
图10为图8所示的波导组件的一光栅矢量图。
耦入区域2具有光栅矢量G0，一维耦出光栅31具有光栅矢量G1，一维耦出光栅32具有光栅矢量G2，第一次反射光栅4(42)具有光栅矢量G3，由于槽线平行及周期和衍射级次设置，从而使得G0+G1+G2+G3＝0，从而使得未被耦出光线经过第一次反射光栅4(42)反射后，由二维耦出光栅3(31、32)耦出，提高了光能利用率、增加了出瞳密度以及增加了亮度均匀性。
图11为图8所示的波导组件的一光栅矢量图。
如图11所示，耦入区域2具有光栅矢量G0，一维耦出光栅31具有光栅矢量G1，一维耦出光栅32具有光栅矢量G2，第一次反射光栅4(42)具有光栅矢量G3，第二次反射光栅5(52)具有光栅矢量G4，由于槽线平行及周期和衍射级次设置，从而使得G0+G1+G2+G3+G4＝0，从而使得经过第一次反射光栅4(42)反射后仍未耦出的光线传输至二次反射光栅5(52)处，由第二次反射光栅5(52)反射回耦出光栅3(31、32)耦出，提高了光能利用率、增加了出瞳密度以及增加了亮度均匀性。
图12为图8所示的波导组件的一光栅矢量图。
如图12所示，耦入区域2具有光栅矢量G0，一维耦出光栅31具有光栅矢量G1，第一次反射光栅4(41)具有光栅矢量G2，一维耦出光栅32具有光栅矢量G3，由于槽线平行及周期和衍射级次设置，从而使得G0+G1+G2+G3＝0，从而使得经过一维耦出光栅31衍射而未被一维耦出光栅32耦出的光，被第一次反射光栅4(41)反射后再被耦出光栅31耦出，提高了光能利用率、增加了出瞳密度以及增加了亮度均匀性。
图13为图8所示的波导组件的一光栅矢量图。
如图13所示，耦入区域2具有光栅矢量G0，一维耦出光栅32具有光栅矢量G1，第二次反射光栅5(51)具有光栅矢量G2，一维耦出光栅32具有光栅矢量G3，由于槽线平行及周期和衍射级次设置，从而使得G0+G1+G2+G3＝0，从而使得经过一维耦出光栅32衍射而未被一维耦出光栅31耦出的光，被第二次反射光栅5(51)反射后再被耦出光栅32耦出，提高了光能利用率、增加了出瞳密度以及增加了亮度均匀性。
进一步地，耦出光栅3的两个一维光栅之间的夹角为50-70度。
在本实施例中，耦出光栅3为矩形光栅、闪耀光栅、倾斜光栅、正弦光栅或全息光栅，并槽深为50～200nm。
在其他实施例中，耦出光栅3为由设在波导片1同一表面的两个一维光栅叠加构成。
在本实施例中，波导片1的厚度为0.3～2.5mm，波导片1的材料为对可见光透明的光学材料，波导片1的折射率为1.4～2.2。
实施例7
图14为本申请一实施例提供的近眼显示设备的结构示意图。
如图14所示，本申请一实施例还提供一种近眼显示设备，包括投影光机6和波导组件，波导组件为上述任一实施例所描述的波导组件。在本实施例中，波导组件，包括：
波导片1；
耦入区域2，设于波导片1的一表面上，耦入区域2用于将光线耦入到波导片1内并使光线在波导片1内扩散传输；
耦出光栅3，设于波导片1的一表面上，耦出光栅3用于将从耦入区域2耦入的光线耦出波导片1；和
第一次反射光栅4，与耦出光栅3设于波导片1的同一表面上并位于耦出光栅3沿光线传输方向上的末端，第一次反射光栅4与耦出光栅3的槽线平行，第一次反射光栅4与耦出光栅3的周期相同且衍射级次中二阶衍射光的衍射效率被设置为最大，或第一次反射光栅4为耦出光栅3周期的一半且衍射级次中一阶衍射光的衍射效率被设置为最大，第一次反射光栅4用于将经过耦出光栅3而未耦出的光线反射回耦出光栅3再耦出。
本实施例提供的波导组件的工作原理过程如下：
投影光机6发出的光线由耦入区域2耦入到波导片1内，并在波导片1内扩散传输至耦出光栅3。耦出光栅3将光线A耦出到波导片1外，被人眼观察到，从而形成可视区域。而未被耦出的光线B会继续传播至第一次反射光栅4处，第一次反射光栅4将光线B反射回耦出光栅3，再由耦出光栅3耦出，即为光线C，光线C与光线A保持平行。
本申请提供的近眼显示设备包括投影光机6和波导组件，而波导组件在波导片1的一侧表面上设置了第一次反射光栅4，并使第一次反射光栅4与耦出光栅3的槽线平行，第一次反射光栅4与耦出光栅3的周期相同且衍射级次中二阶衍射光的衍射效率被设置为最大，或第一次反射光栅4为耦出光栅3周期的一半且衍射级次中一阶衍射光的衍射效率被设置为最大，从而使得经过耦出光栅3 而未耦出的光线被第一次反射光栅4返回耦出光栅3，从而进行耦出，从而提高了波导组件整体的光能利用率、增加了波导组件整体的出瞳密度。且由于经第一次反射光栅4返回再耦出的光线对原已耦出的光线进行了补充，从而提高了波导片1整体可视区域内耦出的光线的亮度均匀性。而且，根据本发明的光学设计，只需要在波导片1的一侧表面上设置第一次反射光栅4，制作工艺简单，便于生产制造。而且本实施例提供的波导组件，第一次未被耦出光栅3耦出的光线只用经过一个第一次反射光栅4就可以返回耦出光栅3处，光能利用率更高。
实施例8
图15为本申请一实施例提供的近眼显示设备的结构示意图。
在本实施例中，波导组件还包括第二次反射光栅5，第二次反射光栅5与第一次反射光栅4设于波导片1的同一表面上。
第二次反射光栅5与第一次反射光栅4相对设置并分别位于耦出光栅3的两侧。
第二次反射光栅5的槽线与耦出光栅3的槽线平行，第二次反射光栅5的周期与耦出光栅3的周期相同且衍射级次中二阶衍射光的衍射效率被设置为最大，或第二次反射光栅5的周期为耦出光栅3周期的一半且衍射级次中一阶衍射光的衍射效率被设置为最大。
经第一次反射光栅4反射后未耦出的光线传输至第二次反射光栅5处，由第二次反射光栅5反射回耦出光栅3再耦出。
本实施例提供的波导组件的工作原理过程如下：
投影光机6发出的光线由耦入区域2耦入到波导片1内，并在波导片1内扩散传输至耦出光栅3。耦出光栅3将光线A耦出到波导片1外，从而形成可视区域。而未被耦出的光线B会继续传播至第一次反射光栅4处，第一次反射光栅4将光线B反射回耦出光栅3，再由耦出光栅3耦出，即为光线C，光线C与光线A保持平行。仍有部分光线D未被耦出继续传输至第二次反射光栅5，由第二次反射光栅5反射回耦出光栅3，耦出光栅3再将光线E耦出。
本实施例提供的近眼显示设备通过在波导组件中的波导片1上设置了第二次反射光栅5，且第二次反射光栅5与第一次反射光栅4位于波导片1的同一侧，且第二次反射光栅5的槽线与耦出光栅3的槽线平行，第二次反射光栅5的周期与耦出光栅3的周期相同且衍射级次中二阶衍射光的衍射效率被设置为最大，或第二次反射光栅5的周期为耦出光栅3周期的一半且衍射级次中一阶衍射光的衍射效率被设置为最大，从而使得经耦出光栅3未耦出的光线被第一反射光栅41反射回耦出光栅3后，仍未耦出的光线再经由第二次反射光栅5反射回耦出光栅3耦出，从而进一步提高了光能利用率、增加了出瞳密度、提高了亮度均匀性。
本发明的描述中，需要说明的是，术语“上”、“下”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本发明和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本发明的限制。此外，术语“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性。
在本发明的描述中，需要说明的是，除非另有明确的规定和限定，术语“安装”、“连通”、“连接”应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或一体地连接；可以是机械连 接，也可以是电连接；可以是直接连通，也可以通过中间媒介间接连通，可以是两个元件内部的连通。对于本领域的普通技术人员而言，可以具体情况理解上述术语在本发明中的具体含义。此外，在本发明的描述中，除非另有说明，“多个”的含义是两个或两个以上。
以上仅为本发明的较佳实施例，并不用以限制本发明，凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。

Claims (20)

  1. 一种波导组件，其特征在于，包括：
    波导片(1)；
    耦入区域(2)，设于所述波导片(1)的一表面上，所述耦入区域(2)用于将光线耦入到所述波导片(1)内并使所述光线在所述波导片(1)内扩散传输；
    耦出光栅(3)，设于所述波导片(1)的一表面上，所述耦出光栅(3)用于将从所述耦入区域(2)耦入的光线耦出所述波导片(1)；和
    第一次反射光栅(4)，与所述耦出光栅(3)设于所述波导片(1)的同一表面上并位于所述耦出光栅(3)沿光线传输方向上的末端，所述第一次反射光栅(4)与所述耦出光栅(3)的槽线平行，所述第一次反射光栅(4)与所述耦出光栅(3)的周期相同且衍射级次中二阶衍射光的衍射效率被设置为最大，或所述第一次反射光栅(4)为所述耦出光栅(3)周期的一半且衍射级次中一阶衍射光的衍射效率被设置为最大，所述第一次反射光栅(4)用于将经过所述耦出光栅(3)而未耦出的光线反射回所述耦出光栅(3)再耦出。
  2. 根据权利要求1所述的波导组件，其特征在于，所述第一次反射光栅(4)包括相分离设置的第一反射光栅(41)和第二反射光栅(42)。
  3. 根据权利要求1或2所述的波导组件，其特征在于，所述第一次反射光栅(4)为正弦光栅、矩形光栅、闪耀光栅或向所述耦出光栅(3)的方向倾斜的倾斜光栅。
  4. 根据权利要求1-3中任一所述的波导组件，其特征在于，还包括第二次反射光栅(5)，所述第二次反射光栅(5)与所述第一次反射光栅(4)设于所述波导片(1)的同一表面上；
    所述第二次反射光栅(5)与所述第一次反射光栅(4)相对设置并分别位于所述耦出光栅(3)的两侧；
    所述第二次反射光栅(5)的槽线与所述耦出光栅(3)的槽线平行，所述第二次反射光栅(5)的周期与所述耦出光栅(3)的周期相同且衍射级次中二阶衍射光的衍射效率被设置为最大，或所述第二次反射光栅(5)的周期为所述耦出光栅(3)周期的一半且衍射级次中一阶衍射光的衍射效率被设置为最大；
    经所述第一次反射光栅(4)反射后未耦出的光线传输至所述第二次反射光栅(5)处，由所述第二次反射光栅(5)反射回所述耦出光栅(3)。
  5. 根据权利要求4所述的波导组件，其特征在于，所述第一次反射光栅(4)包括相分离设置的第一反射光栅(41)和第二反射光栅(42)，所述第二次反射光栅(5)包括相分离设置的第三反射光栅(51)和第四反射光栅(52)，所述第一反射光栅(41)和所述第三反射光栅(51)相对设置，所述第二反射光栅(42)和所述第四反射光栅(52)相对设置。
  6. 根据权利要求4或5所述的波导组件，其特征在于，所述第二次反射光栅(5)为正弦光栅、 矩形光栅、闪耀光栅或向所述耦出光栅(3)的方向倾斜的倾斜光栅。
  7. 根据权利要求1-6中任一所述的波导组件，其特征在于，所述耦出光栅(3)为一维光栅。
  8. 根据权利要求1-7中任一所述的波导组件，其特征在于，所述耦出光栅(3)由两个分别设于所述波导片(1)两个表面上的一维光栅构成或由设在所述波导片(1)同一表面的两个一维光栅叠加构成。
  9. 根据权利要求8所述的波导组件，其特征在于，所述耦出光栅(3)的两个一维光栅之间的夹角为50-70度。
  10. 根据权利要求1-9中任一所述的波导组件，其特征在于，所述耦出光栅(3)为矩形光栅、闪耀光栅、倾斜光栅、正弦光栅或全息光栅，并槽深为50～200nm。
  11. 根据权利要求1-10中任一所述的波导组件，其特征在于，所述第一次反射光栅(4)与所述耦出光栅(3)相接壤。
  12. 根据权利要求1-11中任一所述的波导组件，其特征在于，所述第一次反射光栅(4)的宽度大于3mm。
  13. 根据权利要求4-12中任一所述的波导组件，其特征在于，所述耦出光栅(3)为矩形光栅，所述第一次反射光栅(4)和/或所述第二次反射光栅(5)为倾斜光栅或闪耀光栅。
  14. 根据权利要求1-13中任一所述的波导组件，其特征在于，所述耦入区域(2)包括耦入光栅(21)，所述耦入光栅(21)用于将光线耦入到所述波导片(1)内。
  15. 根据权利要求14所述的波导组件，其特征在于，所述耦入光栅(21)为矩形光栅、闪耀光栅、倾斜光栅、正弦光栅或全息光栅中，并周期为300～600nm、槽深为40～500nm。
  16. 根据权利要求14或15所述的波导组件，其特征在于，所述耦入区域(2)还包括转折光栅(22)，所述转折光栅(22)用于使从所述耦入光栅(21)耦入的光线在所述波导片(1)内扩散传输。
  17. 根据权利要求16所述的波导组件，其特征在于，所述转折光栅(22)为矩形光栅、闪耀光栅、倾斜光栅、正弦光栅或全息光栅中，并周期为300～600nm、槽深为40～500nm。
  18. 根据权利要求1-17中任一所述的波导组件，其特征在于，所述耦入区域(2)与所述耦出光栅(3)位于所述波导片(1)的同一表面上或分别位于所述波导片(1)相背的两个表面上。
  19. 根据权利要求1-18中任一所述的波导组件，其特征在于，所述波导片(1)的厚度为0.3～2.5mm，所述波导片(1)的材料为对可见光透明的光学材料，所述波导片(1)的折射率为1.4～2.2。
  20. 一种近眼显示设备，其特征在于，包括投影光机(6)和波导组件，所述波导组件为权利要求1-19中任一项所述的波导组件。
PCT/CN2021/104696 2020-07-24 2021-07-06 波导组件和包括波导组件的近眼显示设备 Ceased WO2022017171A1 (zh)

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