An electro-optical circuit in which diode-like electrical characteristics of an optical modulator employed therein are used to generate one or more DC-offset levels that place the optical modulator into a proper electrical operating configuration for modulating light transmitted therethrough. In an example embodiment, the optical modulator includes an optical waveguide comprising at least a portion of a semiconductor diode connected to a data driver using a clamping circuit, the clamping circuit being configured to cause a data-modulated electrical signal outputted by the data driver to set a DC-offset level applied to the semiconductor diode. As a result, the use of on-chip and/or on-board bias-tees can advantageously be avoided. In some embodiments, the optical modulator can be driven using two different data signals, each used to set a different respective DC-offset level at the semiconductor diode. In various embodiments, the optical modulator can be an intensity modulator and/or a phase modulator.

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.

An optical device includes an optical waveguide formed of a crystal thin film having an electro-optic effect, an RF electrode configured to apply a high-frequency voltage to the optical waveguide, and a DC electrode configured to apply a DC voltage to the optical waveguide, wherein the RF electrode has a coplanar electrode configuration, and the DC electrode has a microstrip electrode configuration.

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.

An electro-optic modulator is provided, which includes a waveguide layer and an electrode layer, where the electrode layer includes: a plurality of first sub-electrodes and a plurality of first connecting electrodes; a plurality of second sub-electrodes and a plurality of second connecting electrodes; a plurality of third sub-electrodes and a plurality of third connecting electrodes; and a plurality of fourth sub-electrodes and a plurality of fourth connecting electrodes, where the plurality of first sub-electrodes and the plurality of fourth sub-electrodes are grounded, the plurality of second sub-electrodes and the plurality of third sub-electrodes receive differential signals, the plurality of first sub-electrodes and the plurality of second sub-electrodes form a first electric field therebetween, and the plurality of third sub-electrodes and the plurality of fourth sub-electrodes form a second electric field therebetween; and the waveguide layer includes a first waveguide arm and a second waveguide arm.

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 structure forms an MZI in proximity to an electro-optic material. A first (second) electrical input port is configured to receive a first (second) drive signal. The second drive signal has a negative amplitude relative to the first drive signal. A first (second) transmission line is configured to propagate a first (second) electromagnetic wave over at least a portion of a first (second) optical waveguide arm to apply an optical phase modulation. A drive signal interconnection structure is configured to provide a first electrical connection between the first electrical input port and an electrode shared by the transmission lines, and a second electrical connection between the second electrical input port and respective electrodes of the transmission lines; and is configured to preserve relative phase shifts between the drive signals. Input impedances at the first and second electrical input ports are substantially equal to each other.

Methods, systems, and apparatus, including a photonic integrated circuit package, including a photonic integrated circuit chip, including an active optical element; an electrode configured to receive an electrical signal; a ground electrode; and a bond contact electrically coupled to the electrode; and an ASIC chip including circuitry configured to provide the electrical signal; and a bond contact that is electrically coupled to the circuitry; an bridge chip bonded to at least a portion of the photonic integrated circuit chip and at least a portion of the ASIC chip.

A light modulation element constituted by a substrate type optical waveguide has a Mach-Zehnder interferometer; and a traveling wave electrode having a signal electrode arranged at least between a first phase modulator and a second phase modulator and electrically connected to both of the first phase modulator and the second phase modulator. A polarity of a semiconductor region of the first phase modulator connected to the signal electrode and a plurality of a semiconductor region of the second phase modulator connected to the signal electrode are different from each other.

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.