Photonic devices are disclosed including a first cladding layer, a first electrical contact comprising a first lead coupled to a first dielectric portion, a second electrical contact comprising a second lead coupled to a second dielectric portion, a waveguide structure comprising a slab layer comprising a first material, and a second cladding layer. The slab layer may be coupled to the first dielectric portion of the first electrical contact and the second dielectric portion of the second electrical contact. The first dielectric portion and the second dielectric portion may have a dielectric constant greater than a dielectric constant of the first material.

An optical waveguide element includes a substrate having an electro-optic effect, an optical waveguide formed in the substrate, and a control electrode arranged on the substrate to modulate a light wave propagating through the optical waveguide. The control electrode includes a signal electrode and a ground electrode. The signal electrode and the ground electrode are arranged along a modulation effect portion of the optical waveguide that performs modulation. In a shape of a bottom surface of the ground electrode facing the substrate, a slit separating the ground electrode into a first ground electrode close to the signal electrode and a second ground electrode far from the signal electrode is formed in a range corresponding to the modulation effect portion.

An optical waveguide element includes a substrate having an electro-optic effect, an optical waveguide formed in the substrate, and a control electrode arranged on the substrate to modulate a light wave propagating through the optical waveguide. The control electrode includes a signal electrode and a ground electrode. The signal electrode and the ground electrode are arranged along a modulation effect portion of the optical waveguide that performs modulation. In a shape of a bottom surface of the ground electrode facing the substrate, a slit separating the ground electrode into a first ground electrode close to the signal electrode and a second ground electrode far from the signal electrode is formed in a range corresponding to the modulation effect portion.

An optical modulator includes a substrate on which an optical waveguide and a modulation electrode that modulates a light wave propagating through the optical waveguide are formed, and a case housing the substrate, the optical waveguide includes at least an optical branching part that branches one light wave into two light waves or an optical combining part that combines two light waves into one light wave, the modulation electrode has a signal electrode and a ground electrode, and a part of the signal electrode is disposed so as to cross the optical branching part or the optical combining part, and the optical modulator is provided with a suppressing unit that suppresses changes in an intensity ratio of the light waves branched at the optical branching part or an intensity ratio of the light waves combined at the optical combining part, by the signal electrode.

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. According to the present invention, an optical modulator which can suppress electrical crosstalk caused by the noise signal generated in the DC portion electrode and can improve high-frequency characteristics and achieve a widening of bandwidth of the optical frequency band in the high-frequency signals propagating in the RF portion electrode is provided.

Example gratings, grating characteristic adjustment methods and devices are provided. One example grating includes a first optical waveguide region, a second optical waveguide region, and an arrayed waveguide region comprising a plurality of optical waveguides, where the first optical waveguide region is connected to the arrayed waveguide region, and the second optical waveguide region is connected to the arrayed waveguide region. The grating has at least one of the following characteristics: a refractive index of an optical waveguide in the first optical waveguide region can be changed, a refractive index of an optical waveguide in the second optical waveguide region can be changed, a refractive index of an optical waveguide in the arrayed waveguide region can be changed, or an optical waveguide in an arrayed waveguide region can be eliminated.

An optical modulator includes: an optical modulation element that is configured to generate two modulated light beams, each of which is modulated by two sets of electrical signals, and that includes a plurality of signal electrodes; a plurality of signal input terminals, each of which inputs an electrical signal; a relay substrate on which a plurality of signal conductor patterns and a plurality of ground conductor patterns are formed, the relay substrate being configured to propagate the two sets of electrical signals by two pairs of the adjacent signal conductor patterns; and a housing, in which the at least two signal conductor patterns including at least one parts mounting part including electrical circuit elements are configured such that first signal propagation directions, which are signal propagation directions at the parts mounting parts, are different from each other.

An optical modulator includes: an optical modulation element that is configured to generate two modulated light beams, each of which is modulated by two sets of electrical signals, and that includes a plurality of signal electrodes; a plurality of signal input terminals, each of which inputs an electrical signal; a relay substrate on which a plurality of signal conductor patterns and a plurality of ground conductor patterns are formed, the relay substrate being configured to propagate the two sets of electrical signals by two pairs of the adjacent signal conductor patterns; and a housing, in which the at least two signal conductor patterns including at least one parts mounting part including electrical circuit elements are configured such that first signal propagation directions, which are signal propagation directions at the parts mounting parts, are different from each other.

A coplanar waveguide wire electrode structure and a modulator includes a metal electrode and an optical waveguide. The metal electrode includes ground electrodes and a signal electrode. Connecting arms are arranged on both sides of the signal electrode. The inner sides of the ground electrodes are provided with other connecting arms. The tail ends of the connecting arms of the signal electrode are provided with signal wire extension electrodes, and the tail ends of the connecting arms of the ground electrodes are provided with ground wire extension electrodes. A distance is provided between the signal wire extension electrodes and the ground wire extension electrodes. The optical waveguide passes through the spaces between the signal wire extension electrodes and the ground wire extension electrodes. By extending the metal electrode, the distance between the electrodes is actually shortened.

A coplanar waveguide wire electrode structure and a modulator includes a metal electrode and an optical waveguide. The metal electrode includes ground electrodes and a signal electrode. Connecting arms are arranged on both sides of the signal electrode. The inner sides of the ground electrodes are provided with other connecting arms. The tail ends of the connecting arms of the signal electrode are provided with signal wire extension electrodes, and the tail ends of the connecting arms of the ground electrodes are provided with ground wire extension electrodes. A distance is provided between the signal wire extension electrodes and the ground wire extension electrodes. The optical waveguide passes through the spaces between the signal wire extension electrodes and the ground wire extension electrodes. By extending the metal electrode, the distance between the electrodes is actually shortened.