Wavelength multiplexing in waveguides

• US 10,534,175 B2
• Filed: 05/10/2017
• Issued: 01/14/2020
• Est. Priority Date: 05/12/2016
• Status: Active Grant

• Current Assignee: Magic Leap, Inc.
• Original Assignee: Magic Leap, Inc.
• Inventors: Yeoh, Ivan L., Edwin, Lionel E., Macnamara, John Graham
• Primary Examiner(s): Chwasz, Jade R
• Application Number:
  US15/591,668
• Publication Number:
  US 20170329075A1
• Time in Patent Office: 979 Days
• Field of Search: 359 13, 359 34
• CPC Class Codes: G02B 2027/0112 comprising device for genereting colour display
• CPC Class Codes: G02B 2027/0114 comprising dichroic elements
• CPC Class Codes: G02B 2027/012 comprising devices for attenuating parasitic image effects
• CPC Class Codes: G02B 2027/0125 Field-of-view increase by wavefront division
• CPC Class Codes: G02B 2027/0127 comprising devices increasing the depth of field
• CPC Class Codes: G02B 2027/0174 holographic
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 26/0808 by means of one or more diffracting elements
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 5/20 Filters polarising elements G02B5/30
• CPC Class Codes: G02B 6/0016 Grooves, prisms, gratings, scattering particles or rough surfaces
• CPC Class Codes: G02B 6/0026 Wavelength selective element, sheet or layer, e.g. filter or grating
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0035 provided on the surface of the light guide or in the bulk of it
• CPC Class Codes: G02B 6/005 provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02B 6/0056 for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
• CPC Class Codes: G02B 6/0076 Stacked arrangements of multiple light guides of the same or different cross-sectional area
• CPC Class Codes: G02B 6/0083 Details of electrical connections of light sources to drivers, circuit boards, or the like
• CPC Class Codes: G02B 6/34 utilising prism or grating G02B6/293 takes precedence

Abstract

A stacked waveguide assembly can have multiple waveguide stacks. Each waveguide stack can include a plurality of waveguides, where a first waveguide stack may be associated with a first subcolor of each of three different colors, and a second waveguide stack may be associated with a second subcolor of each of the three different colors. For example, the first stack of waveguides can incouple blue, green, and red light at 440 nm, 520 nm, and 650 nm, respectively. The second stack of waveguides can incouple blue, green, and red light at 450 nm, 530 nm, and 660 nm, respectively.

Claims

1. A waveguide assembly comprising:

a light source configured to emit light at colors corresponding to a plurality of different wavelengths, each wavelength of which falls within one of a plurality of different ranges of wavelengths;

a first waveguide stack configured to receive light at first and second colors, wherein the first and second colors correspond to wavelengths that do not fall within the same one of the plurality of different ranges of wavelengths, the first waveguide stack comprising;

a first waveguide comprising a first grating system, the first grating system configured to incouple light at the first color into the first waveguide; and

a second waveguide comprising a second grating system, the second grating system configured to incouple light at the second color into the second waveguide, and

a second waveguide stack configured to receive light at third and fourth colors different from the first and second colors, wherein the third and fourth colors correspond to wavelengths that do not fall within the same one of the plurality of different ranges of wavelengths, the second waveguide stack comprising;

a third waveguide comprising a third grating system, the third grating system configured to incouple light at the third color into the third waveguide; and

a fourth waveguide comprising-a fourth grating system, the fourth grating system configured to incouple light at the fourth color into the fourth waveguide,

wherein the first and third colors correspond to wavelengths that fall within the same one of the plurality of different ranges of wavelengths.

2. The waveguide assembly of claim 1, further comprising a preliminary light filter system comprising a reflective optical element.

3. The waveguide assembly of claim 1, wherein the second and fourth colors correspond to wavelengths that fall within the same one of the plurality of different ranges of wavelengths.

4. A wavelength multiplexing assembly comprising:

a light source that emits light at a plurality of wavelengths falling within a first range of wavelengths and a plurality of wavelengths falling within a second range of wavelengths, the first range of wavelengths corresponding to one of red, green, and blue, and the second range of wavelengths being different from the first range of wavelengths;

a first waveguide stack configured to incouple light at a first wavelength falling within the first range of wavelengths and at a second wavelength falling within the second range of wavelengths, the first wavelength falling outside of the second range of wavelengths and the second wavelength falling outside of the first range of wavelengths, wherein the first waveguide stack comprises;

a first waveguide configured to incouple light at the first wavelength; and

a second waveguide configured to incouple light at the second wavelength; and

a second waveguide stack configured to incouple light at a third wavelength falling within the first range of wavelengths and at a fourth wavelength falling within the second range of wavelengths, the third wavelength falling outside of the second range of wavelengths and the fourth wavelength falling outside of the first range of wavelengths, wherein the second waveguide stack comprises;

a third waveguide configured to incouple light at the third wavelength; and

a fourth waveguide configured to incouple light at the fourth wavelength.

5. The wavelength multiplexing assembly of claim 4, wherein the first waveguide, the second waveguide, the third waveguide, or the fourth waveguide comprises an incoupling optical element, a light distributing element, or an outcoupling optical element.

6. The wavelength multiplexing assembly of claim 5, wherein the incoupling optical element, the light distributing element, or the outcoupling optical element comprises a diffractive optical element.

7. The wavelength multiplexing assembly of claim 6, wherein the diffractive optical element comprises a switchable diffractive optical element.

8. The wavelength multiplexing assembly of claim 4, wherein the waveguide assembly further comprises a preliminary light filter system comprising a refractive optical element.