Non-linear optical grating
AssigneeWestern Digital (Fremont), LLC
InventorsHongxing Yuan, Shing Lee, Zhongyan Wang, Jinshan Li
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Abstract
A method and system for providing an optical grating are described. The optical grating is configured for light of a wavelength. The optical grating includes a top cladding, a core, and bottom cladding. The core resides between the bottom cladding and the top cladding. The core includes a plurality of discrete ridges spaced apart by a nonlinear pitch. The light traverses the top cladding before the core and has a plurality of angles of incidence with the core. The nonlinear pitch of the core is larger for a larger angle of incidence of the plurality of angles of incidence.
Claims20
An optical grating configured for light of a wavelength, the optical grating comprising:
- a top cladding;
- a core having a plurality of discrete ridges spaced apart by a nonlinear pitch, the light traversing the top cladding before the core and having a plurality of angles of incidence with the core, the nonlinear pitch being larger for a larger angle of incidence of the plurality of angles of incidence, the core further including a first optically transparent layer, a stop layer on the first optically transparent layer and a second optically transparent layer on the stop layer, the first optically transparent layer being continuous and including a material, the stop layer being configured to be invisible to the light, and the second optically transparent layer including the material and the plurality of discrete ridges;
- a bottom cladding, the core residing between the bottom cladding and the top cladding;
- and
- a mirror, the bottom cladding residing between the core and the mirror.
An optical grating configured for light of a wavelength, the optical grating comprising:
- a top cladding;
- a core having a core thickness and a plurality of discrete ridges spaced apart by a nonlinear pitch, the light traversing the top cladding before the core and having a plurality of angles of incidence with the core, the nonlinear pitch being larger for a larger angle of incidence of the plurality of angles of incidence, the plurality of angles of incidence corresponding to a principal angle and a divergent, the nonlinear pitch having a range that is larger for the divergence being larger, the core thickness being at least one hundred twenty and not more than two hundred nanometers;
- a bottom cladding having a bottom cladding thickness, the core residing between the bottom cladding and the top cladding;
- and
- a mirror, the bottom cladding residing between the core and the mirror, the bottom cladding thickness configured to recirculate the light reflecting off of the mirror to be returned to a portion of the core at a reflected angle of incidence, the nonlinear pitch at the portion of the core corresponding to the reflected angle of incidence.
A method for providing an optical grating configured for light of a wavelength, the optical grating comprising:
- providing a bottom cladding;
- providing a core having a plurality of discrete ridges spaced apart by a nonlinear pitch, the light having a plurality of angles of incidence with the core, the nonlinear pitch being larger for a larger angle of incidence of the plurality of angles of incidence, the step of providing the core further including providing a first optically transparent layer, providing a stop layer on the first optically transparent layer and providing a second optically transparent layer on the stop layer, the first optically transparent layer being continuous and including a material, the stop layer being configured to be invisible to the light, and the second optically transparent layer including the material and the plurality of discrete ridges;
- and
- a top cladding, the core residing between the bottom cladding and the top cladding, the light traversing the top cladding before the core.
Dependencies are inferred from the claim text.