Abstract:
An electro-optic modulator is provided. The electro-optic modulator includes: an optical splitter; a first optical waveguide and a second optical waveguide; traveling wave electrodes including a first grounding electrode, a first signal electrode, a second signal electrode, and a second grounding electrode; extension electrodes including at least one first signal sub-electrode and two second signal sub-electrodes, where the two second signal sub-electrodes are arranged on both sides of the at least one first signal sub-electrode and the first signal electrode is electrically connected to the first signal sub-electrodes, and the second signal electrode is electrically connected to the second signal sub-electrodes.
Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
A distributed traveling-wave Mach-Zehnder modulator driver having a plurality of modulation stages that operate cooperatively (in-phase) to provide a signal suitable for use in a 100 Gb/s optical fiber transmitter at power levels that are compatible with conventional semiconductor devices and conventional semiconductor processing is described.
Abstract:
Provided is a substrate-type optical waveguide, having a phase modulation function, (i) in which a reflection of a signal to be inputted via a coplanar line is restrained and (ii) which consumes less power. In a case where the substrate-type optical waveguide is partitioned into a plurality of sections by cross sections orthogonal to a direction in which light propagates through a core, a local capacitance in each of the plurality of sections gradually increases as a distance from an entrance end surface increases.
Abstract:
An optical module that processes an input optical signal and outputs a processed optical signal is disclosed. The optical module provides a housing and an optical processing device in the housing. The housing provides an optical input port and an optical output port in a first wall thereof in side-by-side arrangement. A third wall of the housing only provides RF terminals. Second and fourth walls of the housing provide DC terminals. Electrical connection between the DC terminals with DC pads on the device is realized through a wiring substrate whose top avoids an optical path from the optical input port to the input port of the device.
Abstract:
An optical module includes a waveguide substrate having an optical waveguide and electrodes that apply electronic signals to the optical waveguide; a relay substrate disposed adjacently to the waveguide substrate; and a termination substrate disposed sandwiching the waveguide substrate with the relay substrate. The electrodes respectively have a first wiring portion connected from the relay substrate through the waveguide substrate to the termination substrate and a second wiring portion extending from the first wiring portion and branching on the termination substrate. In the second wiring portion, one branched wiring portion has a capacitor and a termination resistor, and another branched wiring portion extends through a bias resistor to a DC electrode on the relay substrate. The second wiring portion is divided into a first group extending in a first direction along the optical waveguide and a second group extending in a direction opposite to the first direction.
Abstract:
Provided is an optical waveguide element module which suppresses reflection of a modulation signal and attenuation of a modulation signal, even when an impedance of a modulation electrode of an optical waveguide element and an impedance of a transmission line for inputting the modulation signal from the external of the optical waveguide element are different from each other. The optical waveguide element module is provided with an optical waveguide element, which has a substrate (1) composed of a material having electro-optical effects, an optical waveguide (2) formed on the substrate, and a modulation electrode (3) which modules optical waves propagating in the optical waveguide; a connector (8), wherein an external signal line which inputs the modulation signal to the modulation electrode is connected to the modulation electrode; and a relay line which connects the connector and the modulation electrode and is formed on a relay substrate (7). Impedance of the relay line changes stepwise or continuously, and reflection of the modulation signal in the optical waveguide element module is suppressed.
Abstract:
Improved optical interferometric modulators have a small waveguide spacing so that the waveguide pair are close to the central electrode, to enhance electro-optic interaction. Asymmetric waveguides with differential indices are used to effectively de-couple the waveguide pair. Multiple sections of asymmetric waveguide pairs with alternating differential indices are used to achieve chirp-free operation. Another version of the device utilizes transmission-line electrode that weave closer to one of the waveguide pair alternately between sections. Another version of the device utilizes waveguide structure that one of the waveguide is closer to the central electrode in alternate section. To improve efficiency further, a DC bias is provided on the outer electrodes configured as an RF-ground but DC-float electrodes. Another improvement is to have a slot is cut underneath the waveguide region to effectively reduce to thickness of the substrate. These improvements lead to higher modulator efficiency.