An optical phase shifter according to an embodiment for achieving the object of the present disclosure includes a first semiconductor layer formed on a substrate, a second semiconductor layer having opposite polarity to the first semiconductor layer, an insulating layer formed between the first semiconductor layer and the second semiconductor layer, and including ferroelectrics, a first electrode connected to the first semiconductor layer, and a second electrode connected to the second semiconductor layer. According to an embodiment, the introduction of ferroelectric materials to a semiconductor-insulator-semiconductor (SIS) optical phase shifter brings about improvement in charge collection efficiency resulting from the negative capacitance effect, thereby achieving higher phase modulation efficiency and lower power consumption. Additionally, it is possible to realize a new structure of optical switch or modulator device through design changes of the type of ferroelectrics and the structural variables.

There is provided an optical signal processing device that generates a mask function in an optical domain to enable high-speed RC processing. For light emitted from a laser light source, an optical modulator modulates at a modulation period at least one of the intensity and phase values of the optical electric field. Thereby, the light emitted from the laser light source becomes an input signal. The input signal is entered into an optical FIR filter unit. For the input signal, the term corresponding to the mask function is multiplied at the optical FIR filter unit and weighted. Thereby, the input signal is converted into an input signal modulated. The modulated input signal enters via an optical coupler, an optical circulation circuit which is loaded with a variable attenuator and a nonlinear response element. The circulating optical signal is branched into two by an optical coupler. One branched light is converted into an intermediate signal at an optical receiver. The intermediate signal is computed by a formula at an electric signal processing circuit, and thereby, the operation as RC can be performed.

An optical modulator includes an optical waveguide extending a length; and a plurality of Radio Frequency (RF) electrodes configured to modulate an optical signal in the optical waveguide, wherein the RF electrodes include an RF crossing located an end of the length and that is configured to equalize the optical signal. The optical signal is equalized via destructive interference after the RF crossing for attenuating modulation amplitude. At or near the end of the length, high frequencies of the optical signal are already strongly attenuated whereas low frequencies of the optical signal are not such that the low frequencies are equalized after the RF crossing.

A liquid crystal display apparatus includes: a liquid crystal cell; a viewer side polarizing plate; a back-surface side polarizing plate, a reflective polarizer, a first prism sheet, a second prism sheet, and a wavelength conversion layer. The first prism sheet and the second prism sheet each has: a first main surface, which is flat; and a second main surface, on which a plurality of unit prisms are arrayed. In the liquid crystal display apparatus, convex portions formed by the plurality of unit prisms on the second main surface of the first prism sheet are bonded to a main surface of the reflective polarizer on an opposite side to the back-surface side polarizing plate, and/or convex portions formed by the plurality of unit prisms on the second main surface of the second prism sheet are bonded to the first main surface of the first prism sheet.

An electro-optic element includes a first waveguide, which is a plasmonic waveguide, including a first core having a ferroelectric material and a cladding having a first cladding portion. The first cladding portion includes, at a first interface with the ferroelectric material, a first cladding material. The electro-optic element includes a first and a second electrode for producing an electric field in the ferroelectric material when a voltage is applied between the first and second electrodes, for modulating a real part of a refractive index of the ferroelectric material. The element includes, in addition, a crystalline substrate on which the ferroelectric material is epitaxially grown with zero or one or more intermediate layers present between the substrate and the ferroelectric material. The element may have a second waveguide, which is a photonic waveguide, including for enabling evanescent coupling between the first and second waveguides.

An electro-optical device is fabricated on a semiconductor-on-insulator (SOI) substrate. The electro-optical device comprises a silicon dioxide layer, and an active layer having ferroelectric properties on the silicon dioxide layer. The silicon dioxide layer includes a first silicon dioxide layer of the SOI substrate and a second silicon dioxide layer converted from a silicon layer of the SOI substrate. The active layer includes a buffer layer epitaxially grown on the silicon layer of the SOI substrate and a ferroelectric layer epitaxially grown on the buffer layer. The electro-optical device further comprises one or more additional layers over the active layer, and first and second contacts to the active layer through at least one of the one or more additional layers. Methods of fabricating the electro-optical device are also described herein.

An electro-optical device is fabricated on a semiconductor-on-insulator (SOI) substrate. The electro-optical device comprises a silicon dioxide layer, and an active layer having ferroelectric properties on the silicon dioxide layer. The silicon dioxide layer includes a first silicon dioxide layer of the SOI substrate and a second silicon dioxide layer converted from a silicon layer of the SOI substrate. The active layer includes a buffer layer epitaxially grown on the silicon layer of the SOI substrate and a ferroelectric layer epitaxially grown on the buffer layer. The electro-optical device further comprises one or more additional layers over the active layer, and first and second contacts to the active layer through at least one of the one or more additional layers. Methods of fabricating the electro-optical device are also described herein.

An optical modulator includes: a ferroelectric substrate in which an input optical waveguide, first and second optical waveguides, and an output optical waveguide are formed; a first electrode formed in a vicinity of the first optical waveguide and to which a first DC voltage is applied; a second electrode formed in a vicinity of the second optical waveguide and to which a second DC voltage is applied; a third electrode electrically connected to the first electrode and formed on both sides of the second electrode; and a fourth electrode electrically connected to the second electrode and formed on both sides of the first electrode. A first gap between the first electrode and the fourth electrode is approximately the same as a second gap between the second electrode and the third electrode. A gap between the third electrode and the fourth electrode is 1-5 times greater than the first gap.

An optical device that includes at least one magnetic element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer; a substrate; and a waveguide is provided, wherein the waveguide and the magnetic element are located on or above the substrate, and wherein at least some of light propagating in the waveguide is applied to the magnetic element.

One embodiment of the disclosure is an electro-optical modulator system. The system may include a ferroelectric material having one or more crystal orientation axes and a Mach-Zehnder interferometer (MZI) modulator comprising an MZI input, an MZI output, a first arm and a second arm, wherein the first arm and the second arm are in optical communication with the MZI input and the MZI output. The ferroelectric material may define or be in communication with a portion of the first arm and the second arm. The first arm may have a first phase parameter and the second arm may have a second phase parameter. The arms may have domain orientations that differ. A portion of the first arm may include a portion of one or more loading layers and a portion of the second arm may include a portion of one or more loading layers.