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.

Systems and methods for activation in an optical circuit in accordance with embodiments of the invention are illustrated. One embodiment includes an optical activation circuit, wherein the circuit comprises a directional coupler, an optical-to-electrical conversion circuit, a time delay element, a nonlinear signal conditioner, and a phase shifter. The directional coupler receives an optical input and provides a first portion to the optical-to-electrical conversion circuit and a second portion to the time delay element, the time delay element provides a delayed signal to the phase shifter, and the optical-to-electrical conversion circuit converts an optical signal from the directional coupler to an electrical signal used to activate the phase shifter to shift the phase of the delayed signal.

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.

Methods, apparatus, systems and articles of manufacture are disclosed to improve performance while reading a one-time programmable memory. An example apparatus includes: a voltage boost circuit including a first output, a second output, a first input configured to be coupled to a controller, a second input coupled to a first output of a decoder, a third input coupled to a second output of the decoder; and a multiplexer including a first input coupled to the first output of the voltage boost circuit, a second input coupled to the second output of the voltage boost circuit, a third input coupled to an array of memory, and an output coupled to a sensing circuit.

A low-jitter digital clock signal generating system which uses optical pulses output from a pulse laser includes a first balanced photodetector that converts first and second optical pulses with a delayed time interval into first and second electrical pulses through first and second photodiodes and outputs first and second modulated pulses generated by allowing the first and second electrical pulses to partially overlap each other, a second balanced photodetector that converts third and fourth optical pulses with the delayed time interval into third and fourth electrical pulses through third and fourth photodiodes, and outputs a second modulated pulse generated by allowing the third and fourth electrical pulses to partially overlap each other, and a capacitor. The capacitor is charged by the first modulated pulse, is discharged by the second modulated pulse, and outputs a voltage according to the charging and discharging as a clock signal.

A low-jitter digital clock signal generating system which uses optical pulses output from a pulse laser includes a first balanced photodetector that converts first and second optical pulses with a delayed time interval into first and second electrical pulses through first and second photodiodes and outputs first and second modulated pulses generated by allowing the first and second electrical pulses to partially overlap each other, a second balanced photodetector that converts third and fourth optical pulses with the delayed time interval into third and fourth electrical pulses through third and fourth photodiodes, and outputs a second modulated pulse generated by allowing the third and fourth electrical pulses to partially overlap each other, and a capacitor. The capacitor is charged by the first modulated pulse, is discharged by the second modulated pulse, and outputs a voltage according to the charging and discharging as a clock signal.

A system for generating clock signals for a photonic quantum computing system includes a pump photon source configured to generate a plurality of pump photon pulses at a first repetition rate, a waveguide optically coupled to the pump photon source, and a photon-pair source optically coupled to the first waveguide. The system also includes a photodetector optically coupled to the photon-pair source and configured to generate a plurality of electrical pulses in response to detection of at least a portion of the plurality of pump photon pulses at the first repetition rate and a clock generator coupled to the photodetector and configured to convert the plurality of electrical pulses into a plurality of clock signals at the first repetition rate.

A system for generating clock signals for a photonic quantum computing system includes a pump photon source configured to generate a plurality of pump photon pulses at a first repetition rate, a waveguide optically coupled to the pump photon source, and a photon-pair source optically coupled to the first waveguide. The system also includes a photodetector optically coupled to the photon-pair source and configured to generate a plurality of electrical pulses in response to detection of at least a portion of the plurality of pump photon pulses at the first repetition rate and a clock generator coupled to the photodetector and configured to convert the plurality of electrical pulses into a plurality of clock signals at the first repetition rate.

A method for adjusting an optical switch keyboard and an optical switch keyboard using the adjusting method are provided. The optical switch keyboard has a number of key units. The method includes the following steps. A scan signal is applied to one of a number of scan lines by a control unit at a first scan time point. A light is emitted by a light source according to the scan signal. A light emitted by the light source is detected by a detecting element to generate a detecting electric signal. The detecting electric signal is read by the control unit to obtain a first read signal voltage. When the first read signal voltage is outside the voltage range of the pressed state of the key unit, the period of the scan signal is increased by a first predetermined amount by the control unit to obtain an adjusted scan signal.

A tunable multi-mode laser is configured to generate a multi-mode optical signal at a tuned wavelength. The laser includes a semiconductor optical gain region, a feedback region, and a phase modulation region between the gain and feedback regions. Each of the regions may be monolithically integrated. A feedback loop is coupled to the tunable laser to receive the optical signal and includes at least one delay line. The delay line may also be monolithically integrated. An output of the delay line is fed back to the tunable multi-mode laser in order to provide at least one of self-injection locking and self-phase locked looping for the multi-mode tunable laser. Each of the optical gain region and phase modulation region of the laser is biased by the output of the delay line in order to reduce phase drift of the optical signal.