An integrated photonics chip comprising: a plurality of optical channels extending a length of the integrated photonics chip; at least one variable optical attenuator (VOA) being optically connected to one of the plurality of optical channels, the at least one VOA comprising a silicon diode; at least one modulator being optically connected to another of the plurality of optical channels, the at least one modulator comprising a silicon diode; wherein the silicon diodes of the at least one VOA and the at least one modulator are adapted to receive biasing voltages; and wherein an application of the biasing voltages causes the silicon diodes of the at least one VOA and the at least one modulator to be reverse-biased, such that the at least one VOA and the at least one modulator are each adapted to detect a photocurrent of an optical signal being propagated along the plurality of optical channels.

A bias control method of a nested optical modulator includes detecting a frequency component that has a frequency equal to a frequency of a dither signal and that is included in an output of the optical modulator, with changing a voltage value of a first bias, to measure a first error-detection value, obtaining a first error-detection curve representing a relationship between the first error-detection value and the voltage of the first bias, obtaining a first correction value based on the first error-detection curve, and obtaining the first error-detection value obtained when the first bias voltage value is equal to a voltage value obtained by adding the first correction value to the first bias voltage value at a zero-crossing point of the first error-detection curve, as a first error control value. The first bias is controlled so that the first error-detection value is the first error control value.

A method of controlling an optical modulator having a first child modulator, a second child modulator, and a parent modulator includes applying a first bias, on which a first dither signal with frequency f1 is superimposed, to the first child modulator, applying a second bias, on which a second dither signal with frequency f2 different from f1 is superimposed, to the second child modulator, applying a third bias, on which a third dither signal with frequency f3 different from both f1 and f2 is superimposed, to the parent modulator. A first error component having the f1 frequency, and a second error component having a beat frequency of f2 and f3 frequencies are detected from the output light from the optical modulator, and a first error signal is generated from the first error component and the second error component to adjust the first bias.

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.

An optical modulator includes: a Mach-Zehnder modulator; and a processor that controls a bias of the Mach-Zehnder modulator. The Mach-Zehnder modulator includes first and second Mach-Zehnder interferometers that are respectively formed on first and second optical paths, a phase shifter that adjusts a phase difference between the first optical path and the second optical path. The processor outputs a first bias signal for controlling an operation point of the first Mach-Zehnder interferometer, a second bias signal for controlling an operation point of the second Mach-Zehnder interferometer, and a third bias signal for controlling a phase-shift amount of the phase shifter, a low-frequency signal being superimposed on the third bias signal. The processor controls the first through third bias signals based on a frequency component of the low-frequency signal that is included in the optical signal output from the Mach-Zehnder modulator.

A device according to one example of principles described herein may include a backplane, electrochemical actuator, and an optical resonator, wherein the electrochemical actuator is located between the backplane and optical resonator. Applied energy may be used to modify the volume of the electrochemical actuator material modifying the resonant/interferometric absorption, transmission, and reflection at visible and/or infrared frequencies.

In an embodiment, a method and apparatus for increasing bandwidth of an optical modulator by applying a first voltage applied to a beginning of a resistive line and applying a second voltage applied to an end of the resistive line; wherein the first voltage is less than the second voltage.

Devices, methods and systems for generating wideband, high-fidelity arbitrary radio frequency (RF) passband signals are described. A voltage tunable optical filter for arbitrary RF passband signal generation includes a first input configured to receive a broadband optical pulse train, a second input configured to receive a first control voltage representative of an amplitude signal, an electrooptic modulator to receive the broadband optical pulse train and the first control voltage, to modulate the broadband optical pulse train in accordance with the amplitude signal, and to produce two complementary optical outputs that form two arms of an interferometer, an optical delay component to impart an optical path difference into one of the complementary outputs of the electrooptic modulator, and a combiner or a splitter to receive two complementary optical outputs of the electrooptic modulator after impartation of the optical path difference and to produce an output interference pattern of fringes.

In one embodiment, an electro-absorption modulator is configured to receive an optical light from an optical light source and outputs a modulated optical signal. The electro-absorption modulator includes a bias voltage that is used to set optimum predetermined modulation performance and an output power of the electro-absorption modulator. A controller is configured to measure a bias current of the optical light source and use a change of the bias current to determine a detuning change that occurs between the electro-absorption modulator and the optical light source. The controller uses the detuning change to automatically control the bias voltage of the electro-absorption modulator to maintain the predetermined modulation performance and maintain the output power of the electro-absorption modulator.

An optical transmitter includes: a modulator, square law detector, and a processor. The modulator generates an optical signal indicating transmission data. The square law detector detects an intensity of the optical signal using a photodetector and output first intensity data indicating the detected intensity. The processor calculates, based on the transmission data, an electric field of the optical signal generated by the modulator by using parameters pertaining to a state of the modulator. The processor calculates second intensity data indicating the intensity of the optical signal based on the calculated electric field. The processor updates the parameters so as to reduce a difference between the first intensity data and the second intensity data. The processor controls the state of the modulator based on the parameters.