Novel methods and systems for waveguide fabrication and design are disclosed. Designs are described for fabricating ridge, buried and hybrid waveguides by a femtosecond pulsed laser. A laser system may combine a diode bar, a wavelength combiner and a waveguide. The waveguide may convert the electromagnetic radiation of an infrared laser into that the visible-wavelength range.

Novel methods and systems for waveguide fabrication and design are disclosed. Designs are described for fabricating ridge, buried and hybrid waveguides by a femtosecond pulsed laser. A laser system may combine a diode bar, a wavelength combiner and a waveguide. The waveguide may convert the electromagnetic radiation of an infrared laser into that the visible-wavelength range.

A coupling structure is presented, which comprises: a waveguide core layer supporting a guided mode and an active layer disposed above the waveguide core layer. In the coupling region, the guided mode is coupled to the active layer, and the active layer outside the coupling region is angled with respect to the active layer in the coupling region such that a distance between the waveguide core layer and the active layer gradually increases away from the coupling region.

Novel methods and systems for waveguide fabrication and design are disclosed. Designs are described for fabricating ridge, buried and hybrid waveguides by a femtosecond pulsed laser. A laser system may combine a diode bar, a wavelength combiner and a waveguide. The waveguide may convert the electromagnetic radiation of an infrared laser into that the visible-wavelength range.

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. The slab extends beyond the elevated ridge along the central axis to the optical interface.

A photonics device is described. The photonics devices include at least one electrode and a waveguide. The waveguide includes electro-optic material(s), a ridge, and a slab. A first portion of the waveguide is proximate to the electrode(s), while a second portion of the waveguide includes a bend. The ridge includes a first side and a second side opposite to the first side. Portions of the slab are proximate to the first side and the second side of the ridge in the first portion of the waveguide. A portion of the slab is omitted in the second portion of the waveguide.

Provided is an optical scanning element, which has a large scan angle, is quickly responsive, and can be downsized. The optical scanning element includes: a photonic crystal layer having holes periodically formed in an electro-optical crystal substrate; a line-defect optical waveguide formed in the photonic crystal layer; a diffraction grating arranged in at least one portion selected from an upper portion, a left side surface portion, and a right side surface portion of the optical waveguide; and electrodes arranged on a left side and a right side of the optical waveguide. The optical scanning element is configured so that an emission angle of light emitted from an upper surface of the optical waveguide is changed.

An interface for an optical modulator and the optical modulator are described. The interface includes first and second differential line pairs. The first differential line pair has a first negative line and a first positive line arranged on opposing sides of a first waveguide. The first negative line is on a distal side of the first waveguide relative to a second waveguide. The first positive line is on a proximal side of the first waveguide relative to the second waveguide. The second differential line pair has a second negative line and a second positive line arranged on opposing sides of the second waveguide. The second negative line is on a distal side of the second waveguide relative to the first waveguide. The second positive line is on a proximal side of the second waveguide relative to the first waveguide. The first and second waveguides each include lithium niobate and/or lithium tantalate.

An optical modulator, including: a substrate; a plurality of electro-optic material layers formed on the substrate; and an electrode formed on the electro-optic material layer; wherein the electro-optic material layer has a patterned RF portion waveguide that applies a modulated signal and a patterned DC portion waveguide that applies a direct current bias signal; and on a section perpendicular to a light propagation direction, the sectional area of the DC portion waveguide is greater than the sectional area of the RF portion waveguide.

A photonics device is described. The photonics devices include at least one electrode and a waveguide. The waveguide includes electro-optic material(s), a ridge, and a slab. A first portion of the waveguide is proximate to the electrode(s), while a second portion of the waveguide includes a bend. The ridge includes a first side and a second side opposite to the first side. Portions of the slab are proximate to the first side and the second side of the ridge in the first portion of the waveguide. A portion of the slab is omitted in the second portion of the waveguide.