Abstract: An optical device is described. The optical device includes a waveguide and an electrode. The waveguide includes at least one electro-optic material. The waveguide has a ridge portion and a thin film portion. The electro-optic material(s) include lithium. The electrode includes a channel region and a plurality of extensions protruding from the channel region. At least one of the extensions extend across at least a portion of the ridge or a portion of the extensions include a first extension and a second extension. The first extension extends from a first portion of the channel region. The second extension extends from a second portion of the channel region such that the first extension is a different height from a substrate structure than the second extension.

Abstract: An optical device including a waveguide and an electrode is described. The waveguide includes at least one optical material having an electro-optic effect. The electrode includes a channel region and extensions protruding from the channel region. The extensions are closer to a portion of the waveguide than the channel region is.

Abstract: An optical device including a waveguide and an electrode is described. The waveguide includes at least one optical material having an electro-optic effect. The electrode includes a channel region and extensions protruding from the channel region. The extensions are closer to a portion of the waveguide than the channel region is. Each extension includes a connecting portion coupled to the channel region and a retrograde portion. The connecting portion is between the retrograde portion and the channel region. The retrograde portion and/or the channel region has a width of not more than one micrometer.

Abstract: An optical device is described. The optical device includes a substrate, an optical channel, a photodiode and an optical path that couples the channel to the photo diode.

Abstract: An optical device is described. The optical device includes a waveguide, a first engineered electrode, and a second engineered electrode. The waveguide includes at optical material(s) having an electro-optic effect. The optical material(s) include lithium. A portion of the waveguide has a waveguide width. The first engineered electrode includes a first channel region and first extensions protruding from the first channel region. The first extensions are closer to the portion of the waveguide than the first channel region is. The second engineered electrode includes a second channel region and second extensions protruding from the second channel region. The second extensions are closer to the portion of the waveguide than the second channel region is. A first extension of the first extensions is a distance from a second extension of the second \extensions. The distance is less than the waveguide width.

Abstract: An optical device is described. The optical device includes a substrate, an optical channel, a photodiode and an optical path that couples the channel to the photo diode. The optical path has an optical path length that is at least one fourth of the optical channel length.

Abstract: Low loss fiber-to-chip interfaces for lithium niobate photonic integrated circuits are provided. An optical circuit includes a waveguide comprising an electro-optical material. The waveguide includes an elevated ridge and a slab underlying the elevated ridge, the elevated ridge and the slab extending along a central axis toward an optical interface. The elevated ridge and the slab each have a plurality of cross-sections along the central axis, each cross-section having a width measured perpendicular to the central axis, wherein the width of elevated ridge is smaller than the width of the slab for every cross-section along the central axis. The elevated ridge includes a tapered portion having a first taper, wherein the cross-section of the elevated portion decreases along the central axis toward the optical interface. The slab includes a tapered portion having a second taper, wherein the cross-section of the slab decreases along the central axis toward the optical interface.

Abstract: An optical modulator includes optical material(s) and first and second differential electrode pairs. The optical material(s) exhibit an electro-optic effect and include lithium. The optical material(s) include first and second waveguides and first and second slab portions adjoining the first and second waveguides. The first differential electrode pair has electrodes arranged on opposing sides of the first waveguide. The second differential electrode pair has electrodes arranged on opposing sides of the second waveguide. The negative electrodes are arranged on distal sides of the waveguide relative to the other waveguide. The positive electrodes are arranged on proximal sides of waveguide relative to the other waveguide. The first and second waveguides, the first and second slab portions, and the first and second differential electrode pairs reside on a substrate structure. No portion of the first slab portion is between the first or second differential electrode pair and the substrate structure.

Abstract: An optical device including a plurality of electrodes, an electro-optic component, an optical grating, and a buried back reflector is described. The electro-optic component includes at least one optical material exhibiting an electro-optic effect. The optical grating is optically coupled with the electro-optic component. In some embodiments, the optical grating includes a vertical optical grating coupler. The buried back reflector is optically coupled with the optical grating. The buried back reflector is configured to increase a coupling efficiency of the optical grating to an out-of-plane optical mode and configured to reduce a performance perturbation to the plurality of electrodes. The buried back reflector may include a metal layer having a thickness of at least thirty nanometers and not more than five hundred nanometers.

Abstract: An optical device is described. The optical device includes a waveguide, a first engineered electrode, and a second engineered electrode. The waveguide includes at optical material(s) having an electro-optic effect. The optical material(s) include lithium. A portion of the waveguide has a waveguide width. The first engineered electrode includes a first channel region and first extensions protruding from the first channel region. The first extensions are closer to the portion of the waveguide than the first channel region is. The second engineered electrode includes a second channel region and second extensions protruding from the second channel region. The second extensions are closer to the portion of the waveguide than the second channel region is. A first extension of the first extensions is a distance from a second extension of the second \extensions. The distance is less than the waveguide width.

Abstract: An optical device including a waveguide and an electrode is described. The waveguide includes at least one optical material having an electro-optic effect. The electrode includes a channel region and extensions protruding from the channel region. The extensions are closer to a portion of the waveguide than the channel region is.

Abstract: An optical device including a waveguide and an electrode is described. The waveguide includes at least one optical material having an electro-optic effect. The electrode includes a channel region and extensions protruding from the channel region. The extensions are closer to a portion of the waveguide than the channel region is.

Abstract: Low loss fiber-to-chip interfaces for lithium niobate photonic integrated circuits are provided. An optical circuit includes a waveguide comprising an electro-optical material. The waveguide includes an elevated ridge and a slab underlying the elevated ridge, the elevated ridge and the slab extending along a central axis toward an optical interface. The elevated ridge and the slab each have a plurality of cross-sections along the central axis, each cross-section having a width measured perpendicular to the central axis, wherein the width of elevated ridge is smaller than the width of the slab for every cross-section along the central axis. The elevated ridge includes a tapered portion having a first taper, wherein the cross-section of the elevated portion decreases along the central axis toward the optical interface. The slab includes a tapered portion having a second taper, wherein the cross-section of the slab decreases along the central axis toward the optical interface.

Abstract: An optical device including a waveguide and an electrode is described. The waveguide includes at least one optical material having an electro-optic effect. The electrode includes a channel region and extensions protruding from the channel region. The extensions are closer to a portion of the waveguide than the channel region is.