A phase modulator of the present disclosure includes a phase distribution arithmetic unit that generates, in a case of reproducing the same reproduction image over a plurality of frames or a plurality of subframes by a light phase modulation element, target phase distribution data that is allowed to reproduce the same reproduction image in at least two adjacent frames among the plurality of frames or in at least two adjacent subframes among the plurality of subframes and that changes phase distribution in the light phase modulation element.

Provided is a first bias power source that generates a first data bias voltage to be applied to an optical modulation unit for the I component, a second bias power source that generates a second data bias voltage to be applied to an optical modulation unit for the Q component, and a third bias power source that generates a quadrature bias voltage to be applied to an optical phase shifter, a data bias voltage adjustment unit that applies a feedback control to each of the first bias power source and the second bias power source, and a quadrature bias voltage adjustment unit that determines whether or not the quadrature bias voltage is optimal on a basis of a second optical QAM signal generated by an IQ optical modulator, and applies a feedback control to the third bias power source, in which a first optical QAM signal and the second optical QAM signal are generated by the IQ optical modulator but the optical phase difference between an optical electric field EI and an optical electric field EQ differs by π.

Embodiments are disclosed for providing a dual-facet distributed feedback (DFB) laser in a Mach-Zehnder modulator (MZM) structure. An example system includes an MZM structure that includes a DFB laser, a first waveguide interferometer arm structure, and a second waveguide interferometer arm structure. The DFB laser is configured to generate an optical input signal where the DFB laser includes a first output facet and a second output facet. The first waveguide interferometer arm structure is coupled to the first output facet of the DFB laser, and the first output facet of the DFB laser emits the optical input signal to the first waveguide interferometer arm structure. The second waveguide interferometer arm structure is coupled to the second output facet of the DFB laser, and the second output facet of the DFB laser emits the optical input signal to the second waveguide interferometer arm structure.

Examples include a driver circuit for driving a voltage controlled electro-optical modulator. The driver circuit includes a supply input and an input for receiving the input voltage. The driving circuit further includes a level shifter circuit, which includes first and second capacitors and is electrically connected to the input, and a voltage distribution circuit, which is electrically connected between the level shifter circuit and an output of the driver circuit for providing the output voltage. The level shifter circuit is configured to generate, based on the input voltage and using the first capacitor, a first voltage varying between the positive supply voltage level and a positive first level that is greater than the positive supply voltage level. The level shifter circuit is also configured to generate, based on the input voltage and using the second capacitor, a second voltage varying between ground and a negative second level.

The present disclosure provide for active boost in an electrical driver via a frequency comparator, configured to determine operational characteristics of an electrical circuit connected to an optical modulator based on a frequency difference between a ring oscillator and the clock signal; an electrical driver configured to drive a phase shift of a first optical signal carried on a first arm relative to a second optical signal carried on a second arm of an optical modulator, the electrical driver comprising: a first signal pathway, connected to the first arm of the optical modulator, wherein the first signal pathway includes: an adjustable gain inverter, electrically connected to first and second nodes; a fixed gain inverter, electrically connected to the first and second nodes; an inductor electrically connected between the second node and a third node; and a non-inverting amplifier connected between the third node and the first node.

A method for controlling the state of two or more liquid crystal-based switchable windows includes in a first step providing correction data which define a relationship between a state signal and an output voltage level. The correction data is provided for each of the switchable windows and the state of the switchable windows may be adjusted according to the state signal between a minimum and maximum level. In a subsequent step, the state signal is provided which defines the desired state of one or more selected switchable windows. In a further step, a required voltage level is determined for setting the desired state based on the state signal and the respective correction data for each of the one or more selected windows. In a subsequent step d), an AC output voltage is generated having the required voltage level for each of the one or more selected windows.

A multi-chip module (MCM-10) includes a substrate (11), one or more photonic chips (14) disposed on the substrate, and an electronic chip (12) disposed on the substrate. The one or more photonic chips include one or more optical channels (22), which are configured to guide propagating optical signals, and two or more photonic modulator-segments (18) coupled to each of the optical channels, each photonic modulator-segment configured to modulate the propagating optical signals responsively to digitally modulated driving electrical signals provided thereto. The electronic chip is configured to generate the digitally modulated driving electrical signals on multiple different lanes (16) of the electronic chip, synchronize the driving electrical signals on the multiple lanes to a same clock, separately control respective phases of the driving electrical signals, fine-tune the voltages of the driving electrical signals on the multiple lanes, and drive the photonic modulator-segments on the photonic chips with the synchronized and phase-controlled driving electrical signals.

An optical Mach-Zehnder superstructure modulator and method that can simultaneously linearize in-phase and quadrature components of optically modulated optical signals and reduce the modulated optical insertion loss (MOIL) by in-phase addition of the in-phase and quadrature components of an amplitude and/or phase modulated optical signal using two high-speed phase modulators embedded in the optical Mach-Zehnder superstructure modulator.

Power consumption in MZI-based integrated photonic switches or filters throughout the operational life can be reduced by reducing fabrication-induced phase misalignment between the unpowered operational mode of the switch or filter and the predominant switch state, and/or by enabling low-power compensation for any such misalignment. In various embodiments, misalignment is reduced by increasing the width of the waveguides implementing the interferometer arms of the MZI, and/or by structuring a region containing the MZI symmetrically to diminish stress-induced misalignment. In some embodiments, phase tuners are used to actively compensate for any phase misalignment, with a tuner drive voltage substantially lower than used to switch to the non-dominant state.

A Dual-polarization optical modulator that can be used to modulate light in both polarization states, in which the operating points of each polarization state can be set at any arbitrary point independently from each other. A novel architecture for an optically-controlled Phased-array beam forming system utilizing this unique dual-polarization is proposed to facilitate simple and practical implementation.