| CPC G09G 3/003 (2013.01) [G02F 1/134309 (2013.01); G02F 1/13439 (2013.01); G09G 3/3413 (2013.01); G09G 3/36 (2013.01)] | 31 Claims |
|
1. A device, comprising:
an optical guiding device configured to guide light to propagate along a first direction within the optical guiding device, the light having a spectral bandwidth with a peak wavelength;
an in-coupling diffractive structure configured to diffract the light to propagate in the optical guiding device; and
one or more out-coupling diffractive structures arranged downstream the in-coupling diffractive structure along the first direction and configured to diffract at least part of the light out of the optical guiding device along a second direction different from the first direction,
wherein the in-coupling diffractive structure is configured to cause a first optical dispersion for the light, and at least one of the one or more out-coupling diffractive structures is configured to cause a second optical dispersion for the light, and wherein the first optical dispersion and the second optical dispersion are compensated with each other, such that light diffracted out of the optical guiding device has no or little optical dispersion, and
wherein the in-coupling diffractive structure comprises a first diffraction grating, and the at least one of the one or more out-coupling diffractive structures comprises a second diffraction grating, and wherein the first diffraction grating and the second diffraction grating are configured to cause the first optical dispersion and the second optical dispersion to be opposite dispersions having a same magnitude for the light.
|