Abstract: An optical device comprises a waveguide plate comprising an entrance pupil grating unit, a left pupil-expanding grating unit, and a right pupil-expanding grating unit. The left and right pupil-expanding grating units are bilaterally symmetric, and left and right exit pupil grating units are bilaterally symmetric. An input light is diffracted by the entrance pupil grating unit to form a first left guided light and a first right guided light, the first left guided light is diffracted by the left pupil-expanding grating unit to form a second left guided light, and the first right guided light is diffracted by the right pupil-expanding grating unit to form a second right guided light. The second left guided light is diffracted by the left pupil-expanding grating unit to form a left output light, and the second right guided light is diffracted by the right pupil-expanding grating unit to form a right output light.

Abstract: An optical device (EPE1) comprises a waveguide plate (SUB1) comprising an in-coupling element (DOE1), a first expander element (DOE2a), a second expander element (DOE2b) and an out-coupling element (DOE3), wherein the out-coupling element (DOE3) is arranged to form combined output light (OUT1) by combining the first output light (OB3a) with the second output light (OB3b), wherein the in-coupling element (DOE1) has a first grating period (d1a) for forming the first guided light (B1a), and wherein the in-coupling element (DOE1) has a second different grating period (d1b) for forming the second guided light (B1b), wherein the optical device (EPE1) comprises a first spectral filter region (C2a) to prevent coupling of red light from the in-coupling element (DOE1) to the out-coupling element (DOE3) via the first expander element (DOE2a). The optical device (EPE1) can display a color image with an extended field of view.

Abstract: A diffractive beam expander device (EPE1) includes a first spectral filter region (C2a) and a second spectral filter region (C2b) to provide a first optical route for blue and green light (B, G), and to provide a second optical router for red light (R). The expander device (EPE1) includes a first Bragg grating region (BRGa) to enhance optical absorption of red light (R) in the first spectral filter region (C2a). The expander device (EPE1) includes a second Bragg grating region (BRGb) to enhance optical absorption of blue light (B) in the second spectral filter region (C2b).

Abstract: An optical device comprises a waveguide plate, which in turn comprises: an in-coupling element to form first guided light and second guided light by diffracting input light, first expander element to form third guided light by diffracting the first guided light, second expander element to form fourth guided light by diffracting the second guided light, and an out-coupling element to form first output light by diffracting the third guided light, and to form second output light by diffracting the fourth guided light, wherein the out-coupling element is arranged to form combined output light by combining the first output light with the second output light, wherein the in-coupling element has a first grating period for forming the first guided light, and wherein the in-coupling element has a second different grating period for forming the second guided light.

Abstract: A optical device includes a waveguide plate, which includes an in-coupling element to form first guided light (B1) and a second guided light (B2) by diffracting input light (IN1), an expander element to form third guided light (B3) by diffracting the first guided light (B1), an out-coupling element to form first output light (OB3) by diffracting the third guided light (B3), a bypass element to form fourth guided light (B4) by diffracting the second guided light (B2), wherein the first guided light (B1) propagates in a first direction, the second guided light (B2) propagates in a second direction, and the angle ?12 between the first direction) and the second direction is in the range of 60° to 120°, wherein the out-coupling element includes one or more augmenting regions.