The present invention relates to a method for operating a pulsed diode-pumped solid-state laser comprising: providing a pump light source for pumping a solid-state laser, said pump light source comprising at least one laser diode unit configured for emitting a series of light pulses for pumping the solid-state laser, modulating the series of light emission pulses of the at least one laser diode unit such that only the light pulses with a frequency close to or equal to a requested frequency setting of the solid-state laser are operated with a/the required pulse amplitude and/or a/the required pulse duration to trigger light emission of the solid-state laser, and such that any other light pulses of the at least one laser diode unit are operated to not trigger light emission of the solid-state laser.

A mode locking device is disclosed for altering repetition rate in a mode-locked laser. In an example device, laser light is coupled from a fiber into a cavity through a sliding pigtail collimator with a diameter selected such that it is a close tolerance fit with a female snout on a package. A lens focuses laser light to an appropriate spot size onto a SAM or SESAM, such that back-reflection into the fiber is maximized, A piezoelectric transducer is mounted in cooperation with the SAM or SESAM for cavity tuning.

Disclosed herein is a single pulse laser apparatus that includes: a resonator having a first mirror, a second mirror, a gain medium, an electro-optic modulator (EOM) configured to perform single pulse switching, and an acousto-optic modulator (AOM) configured to perform mode-locking; a photodiode configured to measure a laser beam oscillated in the resonator; a synchronizer configured to convert an electrical signal, which is generated by measuring the laser beam, into a transistor-transistor logic (TTL) signal; a delay unit configured to set a delay time for the TTL signal to synchronize the EOM and the AOM and output a trigger TTL signal according to the delay time; an AOM driver configured to input the trigger TTL signal to the AOM that performs mode-locking and drive the AOM; and an EOM driver configured to input the trigger TTL signal to the EOM that performs single pulse switching and drive the EOM.

Compact optical frequency sources are described. The comb source may include an intra-cavity optical element having a multi-material integrated structure with an electrically controllable active region. The active region may comprise a thin film. By way of example, the thin film and an insulating dielectric material disposed between two electrodes can provide for rapid loss modulation. In some embodiments the thin film may comprise graphene. In various embodiments of a frequency comb laser, rapid modulation of the CEO frequency can be implemented via electric modulation of the transmission or reflection loss of an additional optical element, which can be the saturable absorber itself. In another embodiment, the thin film can also be used as a saturable absorber in order to facilitate passive modelocking. In some implementations the optical element may be formed on a cleaved or polished end of an optical fiber.

A solid-state laser system may include first and second solid-state laser units, a wavelength conversion system, an optical shutter, and a controller. The first solid-state laser unit and the second solid-state laser unit may output first pulsed laser light with a first wavelength and second pulsed laser light with a second wavelength, respectively. The controller may perform first control and second control. The first control may cause the first and second pulsed laser light to enter the wavelength conversion system at a substantially coincidental timing, thereby causing the wavelength conversion system to output third pulsed laser light with a third wavelength converted from the first wavelength and the second wavelength, and the second control may prevent the first and second pulsed laser light from entering the wavelength conversion system at the coincidental timing, thereby preventing the wavelength conversion system from outputting the third pulsed laser light.

An optical power supply system includes a power sourcing equipment, a powered device and a control device. The power sourcing equipment includes a semiconductor laser that oscillates with electric power and performs pulsed output of feed light. The powered device includes a photoelectric conversion element that converts the feed light into electric power. The control device adjusts a supply amount of the feed light to be supplied from the semiconductor laser by a pulse width of the feed light according to a consumption of the electric power obtained by the conversion by the powered device.

A radiation system for controlling pulses of radiation comprising an optical element configured to interact with the pulses of radiation to control a characteristic of the pulses of radiation, an actuator configured to actuate the optical element according to a control signal received from a controller, the control signal at least partially depending on a reference pulse repetition rate of the radiation system and, a processor configured to receive pulse information from the controller and use the pulse information to determine an adjustment to the control signal. The radiation system may be used to improve an accuracy of a lithographic apparatus operating in a multi-focal imaging mode.

A light amplifier according to an aspect of the present invention includes: a seed light source configured to generate a pulsing seed light; an excitation light source configured to generate excitation light; a light amplifying fiber configured to amplify the seed light by the excitation light and output the amplified light; and a control unit configured to control the seed light source and the excitation light source. The control unit has a mode to control the excitation light's power such that as a set value of a pulse width of the amplified light increases, the amplified light's peak energy increases within a threshold value at a minimum set value of the pulse width.

A frequency comb laser providing large comb spacing is disclosed. At least one embodiment includes a mode locked waveguide laser system. The mode locked waveguide laser includes a laser cavity having a waveguide, and a dispersion control unit (DCU) in the cavity. The DCU imparts an angular dispersion, group-velocity dispersion (GVD) and a spatial chirp to a beam propagating in the cavity. The DCU is capable of producing net GVD in a range from a positive value to a negative value. In some embodiments a tunable fiber frequency comb system configured as an optical frequency synthesizer is provided. In at least one embodiment a low phase noise micro-wave source may be implemented with a fiber comb laser having a comb spacing greater than about 1 GHz. The laser system is suitable for mass-producible fiber comb sources with large comb spacing and low noise. Applications include high-resolution spectroscopy.

Apparatus for and method of controlling a laser system capable of generating bursts of pulses of laser radiation having multiple alternate wavelengths in which an element controlling the wavelength is pre-positioned between bursts to be between its position for generating one wavelength and its position for generating another wavelength. Also disclosed is a system that determines an optimal control waveform for the element to move between positions using quadratic programming, dynamic programing, inversion feed forward control, or iterative learning control. A data storage device such as a pre-populated lookup table or a field programmable gate array may be used to store at least one optimal control parameter for each of a plurality of repetition rates.