A frequency stabilizing system for high precision single-cavity multi-frequency comb includes a single-cavity multi-comb pulse oscillator, a frequency detection system, and a frequency feedback control system. The single-cavity multi-comb pulse oscillator is configured to output mode-locked pulse trains with a certain repetition rate difference at two or more central wavelengths. The frequency detection system is configured to detect the frequency signal, and output the corresponding electrical signal. The frequency feedback control system is configured to process the electrical signal from the frequency detection system, and transmit it to the frequency response component in the single-cavity multi-comb pulse oscillator to control a strain of the frequency response component, so as to realize feedback control on the frequency (repetition rate, repetition rate difference, and carrier envelope offset frequency) of the mode-locked pulse trains.

Embodiments discussed herein refer to LiDAR systems and methods that enable substantially instantaneous power and frequency control over fiber lasers. The systems and methods can simultaneously control seed laser power and frequency and pump power and frequency to maintain relative constant ratios among each other to maintain a relatively constant excited state ion density of the fiber laser over time.

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 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.

A CPA ultrashort pulse laser system is configured with a beam splitter dividing each ultrashort pulse from a seed laser into at least two replicas which propagate along respective replica paths. Each replica path includes an upstream dispersive element stretching respective replicas to different pulse durations. The optical switches are located in respective replica paths upstream or downstream from upstream dispersive elements. Each optical switch is individually controllable to operate at a high switching speed between “on” and “off” positions so as to selectively block one of the replicas or temporally separate the replicas at the output of the switching assembly. The replicas are so stretched that a train of high peak power ultrashort pulses each are output with a pulse duration selected from a fs ns range and peak power of up to a MW level.

Apparatus and methods for producing ultrashort optical pulses are described. A high-power, solid-state, passively mode-locked laser can be manufactured in a compact module that can be incorporated into a portable instrument. The mode-locked laser can produce sub-50-ps optical pulses at a repetition rates between 200 MHz and 50 MHz, rates suitable for massively parallel data-acquisition. The optical pulses can be used to generate a reference clock signal for synchronizing data-acquisition and signal-processing electronics of the portable instrument.

Apparatus for and method of generating multiple laser beams using multiple laser chambers. The relative timing of the beams is controllable so they may, for example, be interleaved, may overlap, or be prevented from overlapping, or may occur in rapid sequence. The beams may have different spectral and power characteristics such as different wavelengths. Also disclosed is a system in which at least one of the multiple laser chambers is configured to generate radiation of two different wavelengths.

A laser system and method. In one example, the laser system includes an optical pulse stretcher configured to stretch pulse durations of an input train of input pulses to produce a train of stretched laser pulses, a pulse replicator module configured to increase a pulse repetition rate of the train of stretched laser pulses to produce a modified pulse train of laser light, a fiber power amplifier configured to amplify the modified pulse train to produce amplified laser pulses, and a pulse compressor that temporally compresses the amplified laser pulses to produce amplified and compressed laser pulses. The system may further include a nonlinear frequency conversion stage comprising at least one nonlinear crystal.

A method and a device for generating a series of laser pulses in a laser device, particularly single and multiple bursts of pulses with a minimum temporal distance between the pulses in a single burst in the picosecond domain. The device includes at least a master oscillator and a regenerative amplifier. The method includes steps of injecting a laser pulse from the master oscillator into the regenerative amplifier, amplifying injected pulse burst during multiple round-trips in an optical cavity of the regenerative amplifier, ejecting amplified pulse burst from the cavity of the regenerative amplifier. The injection step involves applying a first intermediate voltage to an optical switch for a time span, during which pulses from the oscillator are injected into the amplifier, forming a burst of injected seed pulses, which are further amplified in the amplification step, in which the optical switch voltage is set to a locking voltage.

In a laser device that emits pulsed laser light by emitting excitation light to a laser medium in a state in which a first voltage is applied to a Q switch and changing the voltage applied to the Q switch from a first voltage to a second voltage after the emission of the excitation light, the application start timing of the first voltage during a normal operation is set to a timing at which the intensity of the pulsed laser light periodically changing due to the vibration of the Q switch is maximized.