Abstract: An optical device, including a substrate and a plurality of optical waveguide paths formed on the substrate and having slab portions with different thicknesses.

Abstract: An optical device includes: a substrate; and at least two optical waveguides formed on the substrate and facing a multiplexed portion on the substrate in a light propagation direction, wherein in a cross section perpendicular to the light propagation direction, an angle formed between the substrate and a side surface of one optical waveguide, which faces the other optical waveguides, is set to ?, and an angle formed between the substrate and a side surface of one optical waveguide, which does not face the other optical waveguides, is set to ?, satisfying ?<?, wherein ??90°, and ??90°. Therefore, light propagating through the at least two optical waveguides tends to propagate between the optical waveguides when approaching the multiplexed portion. As a result, the light transmission loss during multiplexing light can be reduced.

Abstract: An optical device includes: a substrate; and at least two optical waveguides formed on the substrate and facing to a multiplexed portion on the substrate in a light propagation direction, the optical waveguide includes a lamellar portion and a protruding portion which protrudes from the lamellar portion, in a cross section perpendicular to the light propagation direction, the thickness of the lamellar portion between the protruding portions of the at least two optical waveguides is greater than the thickness of the lamellar portion at the side of a side surface of the protruding portion of the optical waveguides, which does not face to other optical waveguides. Thereby, the transmission loss of light during multiplexing light can be reduced.

Abstract: An optical waveguide element includes: an optical waveguide having a ridge part and a slab part having a thickness less than the ridge part. The optical waveguide includes: a first waveguide having a first ridge with and a first slab film thickness; a second waveguide having a second ridge width and a second slab film thickness; a first intermediate waveguide connected to the first waveguide and having a third ridge width and the first slab film thickness; and a second intermediate waveguide connected to the second waveguide and having a fourth ridge width and the second slab film thickness. The first waveguide, the first intermediate waveguide, the second intermediate waveguide, and the second waveguide are arranged in this order; the second slab film thickness is larger than the first slab film thickness; and the third ridge width is larger than the fourth ridge width.

Abstract: An optical device including: a substrate; an optical waveguide formed at the substrate; and a protective layer formed adjacent to the optical waveguide, wherein the optical waveguide includes multiple side surfaces that intersect the substrate, at least one side surface of the optical waveguide is provided with a rough surface. According to the optical device of the present invention, the light propagation loss can be reduced.

Abstract: An electro-optic device which is provided with: a substrate, an optical waveguide formed on the substrate, and an upper electrode formed on the optical waveguide. The electro-optic device is further provided with a buffer layer formed between the substrate and the upper electrode, and a boundary portion of the optical waveguide and the buffer layer forms an oxide layer different from the optical waveguide and the buffer layer in composition.

Abstract: 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.

Abstract: The present invention provides an optical device and an optical modulator, the optical device comprises an optical waveguide, at an surface of plate-like or film-like electro-optic material forming the optical waveguide, 3 locations are selected in the extension direction of the optical waveguide, and 2 locations are selected in the width direction of the optical waveguide in a range of a region of 0.1×0.1 ?m, and for a total of 6 locations, an surface roughness RMS is measured with Atomic Force Microscope, and an average of the RMS is 5.1 nm or less. According to the optical device in the present invention, the occurrence of micro-cracks at the optical waveguide can be suppressed, thereby reducing the light propagation loss.

Abstract: An optical device, including a substrate; an optical waveguide provided in a predetermined region of the substrate and formed of an electro-optic material film; a protective layer formed adjacent to the optical waveguide; and a non-light-propagation optical waveguide provided outside the predetermined region, wherein the surface roughness of the non-light-propagation optical waveguide is RMS 0.5 nm or more. According to the optical device, the occurrence of micro-cracks on the optical waveguide can be suppressed, thereby reducing the light propagation loss.

Abstract: An electro-optical device includes an optical waveguide and an upper electrode provided on the optical waveguide, the optical waveguide is formed by turning back on a plane, the upper electrode has adjacent parts by turning back the optical waveguide, and an upper layer higher than the upper electrode between the adjacent parts includes a metal layer. Alternatively, an electro-optic device includes a plurality of Mach-Zehnder optical waveguides, wherein the Mach-Zehnder optical waveguide includes a first optical waveguide and a second optical waveguide, a first upper electrode is provided on the first optical waveguide and a second upper electrode is provided on the second optical waveguide, and an upper layer higher than the first upper electrode and the second upper electrode between the first upper electrode and the second upper electrode includes a metal layer. An electro-optic device is capable of suppressing electrical crosstalk between components and seeking wide frequency band.

Abstract: An optical modulators is disclosed. The optical modulator includes a substrate, an optical waveguide formed on the substrate, a signal electrode formed on the optical waveguide via a first buffer layer and applying a modulation signal to the optical waveguide, and a bias electrode formed on the optical waveguide via a second buffer layer and applying a DC bias to the optical waveguide, the first buffer layer and the second buffer layer are formed in such a way that either one of the first buffer layer and the second buffer layer covers an end surface of the other one of the first buffer layer and the second buffer layer at a boundary part of the first buffer layer and the second buffer layer. Accordingly, an optical modulator with high reliability can be provided.

Abstract: An optical waveguide element includes: an optical waveguide having a ridge part and a slab part having a thickness less than the ridge part. The optical waveguide includes: a first waveguide having a first ridge with and a first slab film thickness; a second waveguide having a second ridge width and a second slab film thickness; a first intermediate waveguide connected to the first waveguide and having a third ridge width and the first slab film thickness; and a second intermediate waveguide connected to the second waveguide and having a fourth ridge width and the second slab film thickness. The first waveguide, the first intermediate waveguide, the second intermediate waveguide, and the second waveguide are arranged in this order; the second slab film thickness is larger than the first slab film thickness; and the third ridge width is larger than the fourth ridge width.

Abstract: To provide an optical modulation element whereby reduced drive voltage and suppression of DC drift can be obtained at the same time. An optical modulation element includes: a substrate; and an optical waveguide formed of an electrooptic material film formed on the substrate and having a ridge part which is a protruding portion, and a slab part having a smaller film thickness than the ridge part 11r. The optical waveguide includes a first waveguide part having a first ridge width and a first slab film thickness and to which an RF signal is applied, and a second waveguide part having a second ridge width and a second slab film thickness different from the first slab film thickness and to which a DC bias is applied.

Abstract: The invention relates to an optical modulator. The optical modulator comprising: a substrate; an electro-optical material layer formed on a predetermined region of the substrate; a buffer layer formed on the substrate which is provided so as to cover the electro-optical material layer; and an electrode formed on the buffer layer, and the electro-optical material layer has a RF portion optical waveguide which is applied with a modulation signal and is patterned, and a DC portion optical waveguide which is applied with a DC voltage and is patterned, the electrode has an RF portion electrode formed on the buffer layer where the RF portion optical waveguide is located and a DC portion electrode formed on the buffer layer where the DC portion optical waveguide is located, the film thickness of the DC portion electrode is smaller than the film thickness of the RF portion electrode.

Abstract: An electro-optical device includes a substrate, an optical waveguide formed on the substrate, a buffer layer formed on the substrate which is provided so as to cover the optical waveguide and an electrode formed on the buffer layer, when viewed in a propagation direction of light, a side surface of the optical waveguide has at least one slope change point. An electro-optical device can reduce the driving voltage and provide the propagation loss of light.

Abstract: The optical device includes a substrate and an optical waveguide formed on the substrate, a protrusion portion is formed on the substrate adjacent to the optical waveguide.

Abstract: An optical device including: a substrate; an optical waveguide formed at the substrate; and a protective layer formed adjacent to the optical waveguide, wherein the optical waveguide includes multiple side surfaces that intersect the substrate, at least one side surface of the optical waveguide is provided with a rough surface. According to the optical device of the present invention, the light propagation loss can be reduced.

Abstract: A optical device including: a substrate; an optical waveguide formed at the substrate; and a protective layer formed adjacent to the optical waveguide, wherein the optical waveguide includes multiple side surfaces that intersect the substrate, at least one side surface of the optical waveguide is provided with a rough surface. According to the optical device, the light propagation loss can be reduced.

Abstract: A MEMS package includes a MEMS chip, a package substrate which the MEMS chip is adhered and a thin-film filter which is adhered to the package substrate or the MEMS chip. The thin-film filter includes a thin-film part having a film surface and a rear film surface arranged a rear side of the film surface, and a plurality of through holes being formed to penetrate the thin-film part from the film surface to the rear film surface. The through holes are formed in an adhesive region of the thin-film part. The adhesive region is adhered to the package substrate or the MEMS chip.

Abstract: A thin-film filter includes thin-film part having a film surface and a rear film surface arranged at the rear side of the film surface, a plurality of through holes, being formed to penetrate the thin-film part from the film surface to the rear film surface, the through holes are formed along by a slanting direction being made an acute angle or an obtuse angle with the film surface, and stripes-formed inner wall surfaces. The stripes-formed inner wall surfaces include stripe-like parts formed along by the slanting direction. The stripes-formed inner wall surfaces are formed inside the respective through holes.