Described herein are methods for developing and maintaining pulses that are produced from compact resonant cavities using one or more Q-switches and maintaining the output parameters of these pulses created during repetitive pulsed operation. The deterministic control of the evolution of a Q-switched laser pulse is complicated due to dynamic laser cavity feedback effects and unpredictable environmental inputs. Laser pulse shape control in a compact laser cavity (e.g., length/speed of light<1 ns) is especially difficult because closed loop control becomes impossible due to causality. Because various issues cause laser output of these compact resonator cavities to drift over time, described herein are further methods for automatically maintaining those output parameters.

A laser gas management system includes a gas regeneration apparatus connected to a plurality of excimer laser apparatuses and configured to regenerate a laser gas discharged from the plurality of excimer laser apparatuses into a regenerated gas and supply the plurality of excimer laser apparatuses with the regenerated gas and a controller configured to evaluate whether or not at least one parameter of any of the plurality of excimer laser apparatuses has exceeded a range determined in advance and determine that abnormality has occurred in the gas regeneration apparatus when the at least one parameter has exceeded the range determined in advance in two or more of the excimer laser apparatuses.

A laser cutting device includes a laser oscillator, a cutting nozzle configured to irradiate a work with laser light so as to cut the work, and a controller configured to control the laser oscillator and a drive unit configured to move the cutting nozzle. The controller includes a laser output control unit, a diagnosis performance determination unit configured to determine, when the laser oscillator satisfies a predetermined operation condition, based on a cutting program, whether or not the laser oscillator is diagnosed, and a diagnosis function performance unit configured to issue a laser output command for diagnosis of the laser oscillator to the laser oscillator. When the diagnosis performance determination unit determines that the laser oscillator is diagnosed, the diagnosis performance determination unit outputs the laser output command for diagnosis to the laser oscillator.

A fiber amplifier system including an optical source providing an optical seed beam and an FM electro-optic modulator (EOM) that frequency modulates the seed beam to broaden its spectral linewidth. The system also includes an AM EOM that modulates the seed beam to provide an amplitude modulated seed beam that is synchronized with the frequency modulated seed beam. The system also includes a non-linear fiber amplifier receiving the AM and FM modulated seed beam, wherein the amplitude modulated seed beam causes self-phase modulation in the fiber amplifier that phase modulates the seed beam as it is being amplified by the fiber amplifier that acts to cancel the spectral linewidth broadening caused by the frequency modulation.

An optical power monitor device includes a first optical fiber, including a core and a cladding surrounding the core and being at least one of an incidence-side optical fiber and a launch-side optical fiber connected to each other at a connection point, which is constituted by a curve portion and a linear portion between the curve portion and the connection point, a low refractive index layer that is provided in at least a portion of the linear portion on an outer side of the cladding and has a refractive index lower than a refractive index of the cladding, and a first optical detector that is provided at a position close to at least the curve portion.

A fiber amplifier system including an optical component responsive to a seed beam and causing amplitude modulation that creates a non-uniform spectral transmission having peaks and nulls, and an actuator operable to shift the spectral transmission. The system further includes a fiber amplifier responsive to the seed beam and generating an amplified output beam and a beam sampler responsive to the output beam that provides a sample beam. A detector detects power fluctuations in the sample beam caused by the amplitude modulation, and generates a control metric identifying a magnitude of the fluctuations. A controller uses the control metric to control the actuator to cause it to make adjustments to the seed beam or to the optical component to cause the spectral transmission caused by the optical component to shift so that the peaks or nulls of the spectral transmission align with a center frequency of the seed beam.

A fiber amplifier system including a plurality of optical components in an amplification chain that are responsive to a seed beam and that cause frequency modulation (FM) to amplitude modulation (AM) conversion to the seed beam that creates a non-uniform spectral transmission having a transmission function, where one of the optical components is a fiber amplifier generating an amplified output beam. A programmable spectral filter is controlled to pre-distort the seed beam by applying an inverse of the transmission function that creates a net uniform transmission function by equalizing a net spectral transmission profile of the seed beam at an end of the amplification chain to reduce the amplitude modulation.

A system for transmitting a sequence of at least two data bursts in a fibre optical communications system includes: selection circuitry configured to select one of a data input value, a logical high value or a logical low value such that the selection circuitry selects the data input value during a data transmission period during a defined burst period and selects one of the logical high value and the logical low value during an extension time period during the defined burst period and immediately following the data transmission period, such that for the sequence of at least two bursts, at least one burst has a logical low value extension period and at least one burst has a logical high value extension period; drive circuitry configured to apply a current to a laser diode, the current corresponding to the value selected by the selection circuitry during the defined burst period or a zero value otherwise, the current being such that the laser diode is configured to provide an optical output; an optical sensor module configured to provide a sensor module output corresponding to the optical output of the laser diode; wherein the sensor module output is configured to provide an electrical output proportional to the laser diode's optical output corresponding to the logical high value and the logical low value in the sequence of at least two bursts, and further configured to provide an output corresponding to an average value of the sensor module output during only the data transmission period during the sequence of bursts; and a controller configured to receive values regarding desired minimum and maximum optical output power levels of the laser diode and to receive the electrical output from the optical sensor module proportional to the optical output power level corresponding to the logical high and the logical low values, and to receive the output corresponding to the average value of the sensor module output during only the data transmission period during the sequence of bursts; wherein the controller is configured to use the received information to provide control values for the drive circuitry.

A laser control device includes a processor configured to control, when a control circuit of a laser device detects occurrence of an abnormality in a laser oscillator or a laser optical system and stops laser output from the laser oscillator, the control circuit based on a result of determining whether to enable or disable re-outputting of laser light from the laser oscillator by inputting, to a classifier, input data being at least a part of environmental data and state data about the laser device in a predetermined period including a stop time of laser output. Then, the state data and the input data in the predetermined period include at least one of time-series data about a light amount of laser light and time-series data about a light amount of return light propagating in a direction opposite to a direction of the laser light in the predetermined period.

An excimer laser apparatus according to the present disclosure includes a chamber configured to accommodate a laser gas and a pair of electrodes and generate pulse-oscillating laser light when the gas pressure of the laser gas is controlled in accordance with voltage applied between the pair of electrodes, a power supply configured to apply the voltage between the pair of electrodes, and a controller to which a target value of the spectral linewidth of the laser light is inputted, the controller configured to correct the voltage used to control the gas pressure, when the target value changes from a first target value to a second target value, based on a first function having the second target value as a parameter and control the gas pressure in accordance with the corrected voltage.