Systems and methods for tuning multi-input complex dynamic systems in order to automatically obtain optimal performance are provided. Training is performed by measuring performance of the complex system using an objective function for a sparse sampling of input values over a variety of dynamic regimes. A sparse representation of the performance for each dynamic regime is stored in a library. At run-time, performance is measured and matched to a sparse representation in the library, and the complex system is configured with the optimal input values associated with the matching sparse representation from the library. Performance may then be optimized using an extremum-seeking controller. In some embodiments, the disclosed techniques are applied to a self-tuning mode-locked laser. In some embodiments, the disclosed techniques are applied to other complex systems such as phased array antennas and neurostimulation systems.

A semiconductor laser apparatus is provided. The semiconductor laser apparatus includes a mode-locked semiconductor laser device and an external resonator including a dispersion compensation system, wherein the semiconductor laser apparatus is configured to generate self modulation, to introduce a negative group velocity dispersion into the external resonator, and to provide spectral filtering after the external resonator.

A mode locked laser supplies a high repetition seed pulse train along a seed beam path to a pulse picker having at least one polarizer. A Faraday rotator in optical communication with the seed beam rotates the polarization of the seed beam by about 45. A double pass acousto optical modulator (AOM) receives the seed beam propagating through the Faraday rotator and diffracts the seed beam into a first order first pass beam and a zero order first pass beam. A reflector returns the first pass first order beam into the acousto optical modulator for a second pass. The modulator diffract the beam into a zero order second pass beam and a first order second pass diffracted beam, the first order second pass beam propagating on the substantially same path as the incoming seed beam but in the opposite direction.

A mode-locked laser has optical components integrated into a single apparatus and interrelated via optical free-space coupling. The laser optical cavity path is reduced to less than ten meters, primarily composed of optical gain fiber. A Fabry-Perot filter is matched to the laser pulse repetition frequency. Utilizing a Fabry-Perot filter within the laser optical cavity suppresses supermode spurs in the phase noise spectrum; thereby reducing total timing jitter.

A surface-emitting semiconductor laser system contains at least one MQW unit of at least three constituent QWs, axially separated from one another substantially non-equidistantly. The MQW unit is located within the axial extent covered, in operation of the laser, by a half-cycle of the standing wave of the field at a wavelength within the gain spectrum of the gain medium; immediately neighboring nodes of the standing wave are on opposite sides of the MQW unit. So-configured MQW unit can be repeated multiple times and/or complemented with individual QWs disposed outside of the half-cycle of the standing wave with which such MQW unit is associated. The semiconductor laser further includes a pump source configured to input energy in the semiconductor gain medium and a mode-locking element to initiate mode-locking.

A device for generating temporally distant light pulses is provided, the device including at least a first light source for generating a first sequence of light pulses at a first repetition rate, and a second light source for generating a second sequence of light pulses at a second repetition rate. In some embodiments the device includes at least one actuator element which influences the first and/or the second repetition rate, and a control element which charges the actuator element with a periodical modulation signal for periodical variation of the first and/or second repetition rate. A control circuit is also provided including at least a phase detector, a corrective element, a control element, and a superposition element that forms an actuator signal from a modulation signal and an output signal of the control element, and which charges the actuator element with the actuator signal.

A pulsed laser comprises an oscillator and amplifier. An attenuator and/or pre-compressor may be disposed between the oscillator and amplifier to improve performance and possibly the quality of pulses output from the laser. Such pre-compression may be implemented with spectral filters and/or dispersive elements between the oscillator and amplifier. The pulsed laser may have a modular design comprising modular devices that may have Telcordia-graded quality and reliability. Fiber pigtails extending from the device modules can be spliced together to form laser system. In one embodiment, a laser system operating at approximately 1050 nm comprises an oscillator having a spectral bandwidth of approximately 19 nm. This oscillator signal can be manipulated to generate a pulse having a width below approximately 90 fs. A modelocked linear fiber laser cavity with enhanced pulse-width control includes concatenated sections of both polarization-maintaining and non-polarization-maintaining fibers. Apodized fiber Bragg gratings and integrated fiber polarizers are included in the cavity to assist in linearly polarizing the output of the cavity. Very short pulses with a large optical bandwidth are obtained by matching the dispersion value of the fiber Bragg grating to the inverse of the dispersion of the intra-cavity fiber.