An optical modulation device includes: an optical waveguide formed above a substrate; a phase modulator disposed on part of the optical waveguide; a capacitor connected to the phase modulator and including a lower electrode and an upper electrode; a resistor connected in parallel to the capacitor; and an appended part integrated with the upper electrode and electrically connected to the resistor, wherein the appended part is smaller in area than the capacitor (upper electrode).

A Mach-Zehnder modulator includes: a semiconductor structure having a first waveguide portion, a second waveguide portion, and a third waveguide portion, which are disposed on the first area, the second area, and the third area of a principal surface of substrate, respectively; an embedding resin body having an opening on the first waveguide portion; an ohmic electrode including a first ohmic electrode portion connected to the first waveguide portion through the opening of the embedding resin body, and a second ohmic electrode portion disposed on the embedding resin body in the second area; and a conductor including a first conductive portion extending along the first ohmic electrode portion, and a second conductive portion disposed on the embedding resin body and having a width greater than that of the second ohmic electrode portion, the embedding resin body having a groove extending along an edge of the second ohmic electrode portion.

A photonic platform based polarization controller providing a fixed target polarization is disclosed. The polarization controller has a polarization rotator splitter splitting the beam into first and second feeds corresponding to first and second orthogonal polarization components. A first Mach-Zehnder interferometer (MZI) stage provides a first phase delay between the first and second feeds based on a first control signal, and a first mixer mixes the first and second feeds to provide third and fourth feeds. A second MZI stage provides a second phase delay between the third and fourth feeds based on a second control signal, and a second mixer mixes the third and fourth feeds to provide fifth and sixth feeds. A third MZI stage provides a third phase delay between the fifth and sixth feeds based on a third control signal, and a third mixer mixes the fifth and sixth feeds to provide the fixed target polarization. An optical tap splits a portion of the beam.

An optical Mach Zehnder modulator is described. The optical Mach Zehnder modulator may comprise a plurality of segments separated by curved waveguides. For example, an optical Mach Zehnder modulator may comprise a first waveguide arm having a first pn-junction formed therein, a second waveguide arm having a second pn-junction formed therein, a third waveguide arm coupled to the first waveguide arm via a first curved waveguide and a fourth waveguide arm coupled to the second waveguide arm via a second curved waveguide. The segments may have the same polarities. Alternatively, the segments may have opposite polarities. The different segments may be driven using different RF signals. The RF signals may be delayed from one another.

An optical modulator includes an optical waveguide including at least a first PN junction phase shifter and a second PN junction phase shifter. A driver circuit drives operation of the first and second PN junction phase shifters in response to a pulse amplitude modulated (PAM) analog signal having 2.sup.n levels. The PAM analog signal is generated by a digital to analog converter that receives an n-bit input signal. In an implementation, the optical waveguide and PN junction phase shifters are formed on a first integrated circuit chip and the driver circuit is formed on a second integrated circuit chip that is stacked on and electrically connected to the first integrated circuit chip.

A semiconductor Mach-Zehnder optical modulator includes input side lead-out lines, phase modulation electrode lines, output side lead-out lines, electrodes that apply modulation signals propagating through the phase modulation electrode lines to respective waveguides, and ground lines. Furthermore, at least one n-type semiconductor layer or p-type semiconductor layer is formed between a substrate and a dielectric layer in a lower layer under the output side lead-out lines intermittently along the output side lead-out lines.

A substrate (102) having a piezoelectric effect, optical waveguide (138a, 140a, 138b, 140b, and the like) formed on the substrate, and a plurality of bias electrodes (152a, 152b, and the like) that control an optical wave (s) which propagate through the optical waveguides are provided, and the bias electrodes are constituted and/or disposed such that an electrical signal applied to one of the bias electrodes is prevented from being received by another one of the bias electrodes through a surface acoustic wave.

An optical modulator element includes first and second optical modulators, an optical input terminal, and a branch coupler. Each of the first and second optical modulators includes a pair of Mach-Zehnder waveguides, a first optical coupler to split rays from the branch coupler into the pair of Mach-Zehnder waveguides, and a second optical coupler to combine rays transmitted through the pair of Mach-Zehnder waveguides. The first and second optical modulators are disposed in such a manner that a traveling direction of rays propagating through the pair of Mach-Zehnder waveguides of the first optical modulator and a traveling direction of rays propagating through the pair of Mach-Zehnder waveguides of the second optical modulator are angled toward each other.

A coherent frequency modulated receiver for receiving and detecting arriving optical signals which comprises an electrically controllable optical beam scanner receiving optical input beams arriving at different angles in a field of view of the electrically controllable optical beam scanner, the electrically controllable optical beam scanner conveying a scanned optical input beam as its output optical beam; a grating coupler responsive to the output or reflected optical beam of the electrically controllable optical beams scanner, the grating coupler having a waveguided output; an optical local oscillator laser having a waveguided output; an FMCW signal generator; an optical modulator responsive to the optical waveguided outputs of the optical local oscillator laser and also to an electrical FMCW signal from the FMCW signal generator; a pair of second order non-linear optical elements for frequency upconverting respective outputs of the optical modulator and the grating coupler; and at least one photodiode optically coupled to an outputs of the pair of second order non-linear optical elements.

An optical modulator comprising a waveguide for propagating an optical signal comprising a proximate arm configured to communicate a proximate portion of the optical signal, and a distal arm configured to communicate a distal portion of the optical signal, a proximate diode configured to modulate the proximate portion of the optical signal, a distal diode configured to modulate the distal portion of the optical signal, and an electrical input electrically coupled to opposite signed interfaces of the proximate diode and the distal diode such that an electrical driving signal propagated along the electrical input causes an equal and opposite modulation of the proximate portion of the optical signal in the proximate arm of the waveguide and the distal portion of the optical signal in the distal arm of the waveguide.