Various embodiments of the present technology enable growth of a-axis oriented barium titanate (BTO) films by inserting a relaxed strain control layer having a larger lattice constant than the c-axis of BTO and a similar thermal expansion mismatch. As a result, in-plane tensile stress causes BTO to grow with its ferroelectric polarization in-plane. Some embodiments allow for BTO films to immediately be grown on silicon with a-axis orientation, and without the need to create thick layers for relaxation. Using various embodiments of the present technology, the BTO can be grown in-plane with minimal dislocation density that is confined to the interface region.

An optical element includes a primary electrode, a secondary electrode overlapping at least a portion of the primary electrode, and an electrostrictive ceramic layer disposed between and abutting the primary electrode and the secondary electrode, where the electrostrictive ceramic may be characterized by a relative density of at least approximately 99%, an average grain size of at least approximately 300 nm, a transmissivity within the visible spectrum of at least approximately 70%, and bulk haze of less than approximately 10%. Optical properties of the electrostrictive ceramic may be substantially unchanged during the application of a voltage to the electrostrictive ceramic layer and the attendant actuation of the optical element.

Various embodiments may relate to a tunable optical device. The tunable optical device may include a ferroelectric layer including a ferroelectric material. The tunable optical device may also include one or more first electrodes on a first side of the ferroelectric layer. The tunable optical device may further include one or more second electrodes on a second side of the ferroelectric layer opposite the first side. A refractive index of the ferroelectric material may be changeable in response to a potential difference applied between the one or more first electrodes and the one or more second electrodes. The one or more first electrodes and the one or more second electrodes may be configured to allow visible light or infrared light to pass through.

A photonic integrated circuit comprises a silicon nitride waveguide, an electro-optic modulator formed of a III-nitride waveguide structure disposed on the silicon nitride waveguide, a dielectric cladding covering the silicon nitride waveguide and electro-optic modulator, and electrical contacts disposed on the dielectric cladding and arranged to apply an electric field to the electro-optic modulator.

A transparent optical element may include a layer of an electroactive ceramic disposed between transparent electrodes, such that the electrodes are each oriented perpendicular to a non-polar direction of the ceramic layer. Optical properties of the optical element, including transmissivity, haze, and clarity may be improved by the application of a voltage to the electroactive ceramic, and an associated phase transformation.

An optical isolator includes a Faraday rotator including a trivalent ion exchange TAG (terbium-aluminum garnet), and arranged around the Faraday rotator, a central hollow magnet and a first and a second hollow magnet units arranged to sandwich the central hollow magnet in an optical axis direction. A magnetic flux density B [T] in the Faraday rotator and an optical path length L [mm] where the Faraday rotator is arranged satisfy

0<B  (1) and

14.0≤L≤24.0  (2).

The optical isolator, compared with a conventional Faraday rotator such as a terbium-gallium garnet (TGG) crystal, contributes to reduction of a thermal lensing effect, being a pending problem, in a high-output fiber laser.

An optical isolator includes a Faraday rotator including a trivalent ion exchange TAG (terbium-aluminum garnet), and arranged around the Faraday rotator, a central hollow magnet and a first and a second hollow magnet units arranged to sandwich the central hollow magnet in an optical axis direction. A magnetic flux density B [T] in the Faraday rotator and an optical path length L [mm] where the Faraday rotator is arranged satisfy

0<B  (1) and

14.0≤L≤24.0  (2).

The optical isolator, compared with a conventional Faraday rotator such as a terbium-gallium garnet (TGG) crystal, contributes to reduction of a thermal lensing effect, being a pending problem, in a high-output fiber laser.

A photonic integrated circuit comprises a silicon nitride waveguide, an electro-optic modulator formed of a III-nitride waveguide structure disposed on the silicon nitride waveguide, a dielectric cladding covering the silicon nitride waveguide and electro-optic modulator, and electrical contacts disposed on the dielectric cladding and arranged to apply an electric field to the electro-optic modulator.

A functional element housing package includes a pin terminal disposed in an outer region of a housing for housing a functional element. A wiring substrate is connected with the pin terminal. The wiring substrate includes a through hole for receiving the pin terminal, a first metallic layer disposed around an opening of the through hole on a side of the wiring substrate which side is located close to the housing, a second metallic layer disposed around an opening of the through hole on a side of the wiring substrate which is opposed to the side located close to the housing, the second metallic layer being greater in area than the first metallic layer, a connection wiring line connected to the first metallic layer or the second metallic layer, and a solder which connects the pin terminal to each of the first metallic layer and the second metallic layer.

Electronic device components that include a glass portion and a ceramic or a glass ceramic portion are disclosed. The ceramic or glass ceramic portions of the component may be located to provide desired performance characteristics to the component, which may be an enclosure component. In addition, regions of compressive stress may be formed within the glass portion, the glass ceramic portion, or both to further adjust the performance characteristics of the component. Electronic devices including the components and methods for making the components are also provided.