An optical resonant modulator based on coupling modulation, comprising a resonant structure with an embedded Mach-Zehnder interferometer that is differentially driven to induced amplitude modulation at the output port. The principle of coupling modulation enables high data/baud rates to be achieved in a photonic integrated circuit, e.g. silicon, footprint that is considerably smaller than that of a conventional traveling-wave Mach-Zehnder modulator, in particular by utilizing space saving features, such as ring resonator phase shifters and bend waveguide arms.

A optical modulator with reduced with a reduced amount of ripple is provided. A Mach-Zehnder optical modulator includes a phase modulation unit including optical waveguides having a PN junction structure and traveling wave electrodes, and a dummy phase modulation unit including portions of the traveling wave electrodes, the portions being obtained by forming the respective traveling wave electrodes longer than the phase modulation unit in the light propagation direction of the phase modulation unit, and optical waveguides having the same PN junction structure as that of the optical waveguides of the phase modulation unit and not connected to the optical waveguides of the phase modulation unit.

To provide an optical waveguide device that is small, has low optical loss, and has long-term stability. Provided is an optical waveguide device in which an optical waveguide A (20) is formed on a first substrate (2), an end portion of the first substrate has an input portion that inputs a light wave into the optical waveguide A or an output portion that outputs a light wave from the optical waveguide A, an optical waveguide B (10) is formed on a second substrate (1), the second substrate has an optical modulation portion that modulates a light wave propagating through the optical waveguide B, and at least a part of the optical waveguide A (20) has a conversion portion (20) that converts an optical mode field diameter.

A traveling wave electrode modulator and a photonic integrated chip including the same. The traveling wave electrode modulator comprises a silicon base, an optical waveguide and a doped transitional area disposed in the silicon base, and a traveling wave electrode structure electrically connected to the transitional area. The traveling wave electrode structure comprises at least one layer of a continuous electrode continuously extending along the direction of extension of the optical waveguide, at least one layer of a periodic electrode periodically disposed along the direction of extension of the optical waveguide, and a conductive structure. The continuous electrode is electrically connected to the periodic electrode via the conductive structure, and the traveling wave electrode structure is electrically connected to the transitional area via the conductive structure.

An optical device includes a semiconductor substrate having a major surface, and an optical waveguide structure on the major surface. The optical waveguide structure comprises a lower optical core, an upper optical core, and an intermediate optical cladding, where the upper optical core is vertically above the lower optical core and the intermediate optical cladding separates and is in contact with the optical cores. The optical cores are optically coupled in first and second sections of the optical waveguide structure near the respective first and second ends, and the optical waveguide structure has a parallel pair of optical waveguides extending from the first section to the second section with each of the optical waveguides including one of the optical cores.

An optical modulator includes a semiconductor substrate and an optical waveguide portion disposed on the semiconductor substrate. A signal contact that extends alongside the optical waveguide portion is disposed on the semiconductor substrate. A first ground line is disposed on the semiconductor substrate spaced away from the signal contact by a first spacing. A second ground line is disposed on the semiconductor substrate spaced away from the signal contact by a second spacing opposite the first ground line. The first spacing is different from the second spacing.

A travelling wave electro-optic modulator comprising a substrate; first and second parallel spaced apart electrode strips arranged on the substrate; first and second optical waveguides arranged on the substrate, the optical waveguides being positioned between the first and second electrode strips and extending parallel thereto; the first electrode strip comprising at least one portion extending proximate to the first optical waveguide; the second electrode strip comprising at least one portion extending proximate to the second optical waveguide; a semiconductive backplane layer arranged within the substrate and extending between the waveguides; and, a matched termination connected to the first and second electrode strips, the matched termination comprising (a) a serpentine electrically conductive strip arranged on the substrate and connecting the first and second electrode strips together; and, (b) a semiconductive backplane matching element, the backplane matching element comprising a plurality of semiconductive backplane plates connected together by at least one semiconductive backplane arm, the plates and at least one backplane arm being arranged within the substrate, the plates being arranged proximate to the electrode strips such that each electrode strip is capacitively coupled to at least one backplane plate; the serpentine electrically conductive strip being arranged such that at least a portion of its length is proximate to at least one backplane arm such that the two are electrically coupled together.

A velocity mismatch between optical signals and microwave electrical signals in electro-optic devices, such as modulators, may be compensated by utilizing different lengths of bends in the optical waveguides as compared to the microwave electrodes to match the velocity of the microwave signal propagating along the coplanar waveguide to the velocity of the optical signal. To ensure the electrode bends do not affect the light in the optical waveguide bends, the electrode may have to be rerouted, e.g. above or below, the optical waveguide layer. To ensure that the pair of optical waveguides have the same optical length, a waveguide crossing may be used to cross the first waveguide through the second waveguide.

Provided is a distributed optical phase modulator, comprising: a substrate (10); an optical waveguide (20) arranged on the substrate (10); a drive electrode (30) that is arranged on the substrate (10) and comprises a plurality of sub drive electrodes (31) arranged at intervals; and at least one shielding electrode (40), wherein at least some shielding electrodes and the sub drive electrodes (31) are arranged at intervals. The optical waveguide (20) sequentially passes through the sub drive electrodes (31) and the shielding electrodes (40). The length of each part of the drive electrode (30) is far less than the total length of an equivalent traditional modulator, and the drive signal voltage of each part is also far less than the drive signal voltage of the equivalent traditional modulator. In each part of the drive electrode (30), the propagation of an optical signal and the propagation of an electrical signal can be approximately synchronous, even synchronous. The phenomenon of walk-off between the optical signal and the electrical signal is minimized, and the upper limit of a modulation bandwidth is improved. The shielding electrodes (40) are respectively arranged between the sub drive electrodes (31), so that crosstalk between the sub drive electrodes (31) can be shielded, and crosstalk between the sub drive electrodes (31) can be greatly reduced.

An optical waveguide element including a substrate, an optical waveguide formed on the substrate, and an electrode for controlling a light wave propagating through the optical waveguide, in which the optical waveguide and the electrode have an intersection in which the optical waveguide and the electrode intersect with each other, and at the intersection, the electrode has a multilayer structure including a plurality of metal layers made of a metal material, and a resin layer made of a resin material is formed between the electrode and the substrate.