The present disclosure relates to a method including the following steps: a) forming a waveguide from a first material, the waveguide being configured to guide an optical signal; b) forming a layer made of a second material that is electrically conductive and transparent to a wavelength of the optical signal, steps a) and b) being implemented such that the layer made of the second material is in contact with at least one of the faces of the waveguide, or is separated from the at least one of the faces by a distance of less than half, preferably less than a quarter, of the wavelength of the optical signal. The application further relates to a phase modulator, in particular obtained by such a method.

Provided is a method for manufacturing an optical component, including the following steps: producing at least one optical waveguide or a part of an optical waveguide on a substrate, where producing the optical waveguide or the part of the optical waveguide includes producing a waveguide core or a portion of a waveguide core, and where the waveguide core or the portion of the waveguide core includes silicon nitride, a polymer or a III-V semiconductor material; and arranging at least one layer of lithium niobate on a side of the waveguide core or of the portion of the waveguide core facing away from the substrate. After arranging at least one layer of lithium niobate at least one of the following steps is carried out: structuring at least one layer of lithium niobate, producing a further portion of the waveguide core and/or arranging at least one contact structure for electrically contacting the at least one layer of lithium niobate.

Provided is a method for manufacturing an optical component, including the following steps: producing at least one optical waveguide or a part of an optical waveguide on a substrate, where producing the optical waveguide or the part of the optical waveguide includes producing a waveguide core or a portion of a waveguide core, and where the waveguide core or the portion of the waveguide core includes silicon nitride, a polymer or a III-V semiconductor material; and arranging at least one layer of lithium niobate on a side of the waveguide core or of the portion of the waveguide core facing away from the substrate. After arranging at least one layer of lithium niobate at least one of the following steps is carried out: structuring at least one layer of lithium niobate, producing a further portion of the waveguide core and/or arranging at least one contact structure for electrically contacting the at least one layer of lithium niobate.

According to an example aspect of the present invention, there is provided an electro-optic plasmonic device comprising: a slot waveguide that is defined by a first metallic electrode, a second metallic electrode and dielectric material in a slot between the first and second metallic electrodes. The device is configured to utilize the electric field induced Pockels effect.

According to an example aspect of the present invention, there is provided an electro-optic plasmonic device comprising: a slot waveguide that is defined by a first metallic electrode, a second metallic electrode and dielectric material in a slot between the first and second metallic electrodes. The device is configured to utilize the electric field induced Pockels effect.

In order to provides an optical waveguide element and an optical modulator that can prevent the damage to the substrate and the deterioration of the properties of the substrate that may occur due to the stress, by reducing the influence of stress on the substrate by the buffer layer, the optical waveguide 1 is provided with a substrate 5 having an electro-optical effect; an optical waveguide 10 formed on the substrate 5; a first buffer layer 9a provided on the substrate 5; and a second buffer layer 9b provided under the substrate 5, wherein the first buffer layer 9a and the second buffer layer 9b are composed of substantially the same material and have substantially the same thickness, and the first buffer layer 9a and the second buffer layer 9b are formed to be in contact with an upper surface and lower surface of the substrate 5, respectively.

In order to provides an optical waveguide element and an optical modulator that can prevent the damage to the substrate and the deterioration of the properties of the substrate that may occur due to the stress, by reducing the influence of stress on the substrate by the buffer layer, the optical waveguide 1 is provided with a substrate 5 having an electro-optical effect; an optical waveguide 10 formed on the substrate 5; a first buffer layer 9a provided on the substrate 5; and a second buffer layer 9b provided under the substrate 5, wherein the first buffer layer 9a and the second buffer layer 9b are composed of substantially the same material and have substantially the same thickness, and the first buffer layer 9a and the second buffer layer 9b are formed to be in contact with an upper surface and lower surface of the substrate 5, respectively.

This optical modulator includes an optical modulation element having a first optical waveguide, a second optical waveguide, a first electrode configured to apply an electric field to the first optical waveguide, and a second electrode configured to apply an electric field to the second optical waveguide; and a control unit configured to control an applied voltage between the first electrode and the second electrode. The control unit sets Vpp to 0.06×Vπ≤Vpp≤0.4×Vπ when a half-wavelength voltage of the optical modulation element is Vπ and an applied voltage width that is an amplitude of an applied voltage applied to the optical modulation element is Vpp, and sets Vn≤Vmin≤Vn+0.29×Vπ or Vn−0.29×Vπ≤Vmax≤Vn when a minimum value and a maximum value of a voltage applied to the optical modulation element are respectively Vmin and Vmax and a null point voltage of the optical modulation element is Vn.

This optical modulator includes an optical modulation element having a first optical waveguide, a second optical waveguide, a first electrode configured to apply an electric field to the first optical waveguide, and a second electrode configured to apply an electric field to the second optical waveguide; and a control unit configured to control an applied voltage between the first electrode and the second electrode. The control unit sets Vpp to 0.06×Vπ≤Vpp≤0.4×Vπ when a half-wavelength voltage of the optical modulation element is Vπ and an applied voltage width that is an amplitude of an applied voltage applied to the optical modulation element is Vpp, and sets Vn≤Vmin≤Vn+0.29×Vπ or Vn−0.29×Vπ≤Vmax≤Vn when a minimum value and a maximum value of a voltage applied to the optical modulation element are respectively Vmin and Vmax and a null point voltage of the optical modulation element is Vn.

An optical circuit element capable of preventing stray light propagated through a part including a substrate of the optical circuit element from being emitted to the outside is provided. The optical circuit element has a substrate, an optical waveguide layer that is formed on one surface of the substrate, and a protective layer that is overlaid on the optical waveguide layer. The optical waveguide layer has an optical waveguide configured for light to be propagated therethrough. A groove portion, which reaches to a position deeper than the one surface from a surface of the protective layer toward the substrate, is formed. The optical circuit element further includes a light absorption layer that covers at least a bottom surface and a side surface of the groove portion.