A method, apparatus and system for coherent beam combining (CBC) in high energy fiber laser (HEL) systems include generating a reference interference pattern of a signal source including at least two single-mode optical signals, capturing and evaluating the reference interference pattern, maximizing an intensity of the selected area of the captured, reference interference pattern, increasing a linewidth of the optical signals generating the reference interference pattern until the reference interference pattern is degraded, and adjusting a delay time of one of the at least two single-mode optical signals until the reference interference pattern is recovered, by adjusting a value of a delay of a delayed RF signal with a broaden linewidth to a respective EO linewidth broadening modulator in at least one channel of the at least two single-mode optical signals while evaluating the interference pattern on a display device.

The ultrafast pulse fiber laser system is configured with scalable output power and operative to reduce degradation of pulse integrity. The disclosed laser system is configured to suppress the pulse distortion through improvement of initial pulse contrast between main and side pulses and improved pulse shape using chirped pulse amplification and a fast intensity modulator driver by a corrected electrical signal that is generated from the original optical signal. The structure providing the improvement includes the photodiode, which is operative to measure the chirped optical pulse and convert it to the electrical signal, and analog electronics that quickly converts the electrical signal to the required signal that suppress the side pulses.

Operating an optical frequency comb assembly includes operating an optical frequency comb source to generate laser light constituting an optical frequency comb and introducing the laser light into a common light path and seeding at least one branch light path by the laser light from the common light path, the branch light path comprising at least one optical element. For the branch light path, a phase difference of a first frequency mode .sub.1 of the optical frequency comb is determined between laser light coupled out at a reference point within the frequency comb assembly upstream of the at least one optical element and laser light coupled out at a measurement point provided in the branch light path downstream of the at least one optical element. Phase correction for the laser light from the branch light path is based on a deviation of the determined phase difference from a target value.

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 device includes a laser source, an amplifier, an optical sensor and a spectrometer. The laser source is configured to produce a seed laser beam. The amplifier includes gain medium and a discharging unit. The discharging unit is configured to pump the gain medium for amplifying power of the seed laser beam. The optical sensor is coupled to the amplifier and configured for sensing an optical emission generated in the amplifier while the gain medium is discharging. The spectrometer is coupled with the optical sensor and configured to measure a spectrum of the optical emission.

A burst logging system logs and transmits to a local or remote computing system event data related to errors in and or potential failures of laser system components. The system further provides for capturing data at different rates from different sensors, synchronization of data capture associated with system events and the possibility for aggregation of data from multiple systems, which can in turn be leveraged to predict and or remediate future system events.

In an example, a mode-locked laser includes a resonator cavity having a saturable absorber, a hollow core fiber coupled to the saturable absorber, and an optical amplifier optically coupled between the hollow core fiber and an output coupler. The mode-locked laser further includes a first pump laser and a wavelength division multiplexer coupled to the first pump laser. The wavelength division multiplexer is configured to couple light from the first pump laser into the resonator cavity to pump the optical amplifier. The mode-locked laser is configured to generate a pulse waveform at a repetition rate of approximately 100 MHz to 200 MHz.

A laser processing method of performing laser processing on a transparent material that is transparent to ultraviolet light by using a laser processing system includes: performing relative positioning of a transfer position of a transfer image and the transparent material in an optical axis direction of a pulse laser beam so that the transfer position is set at a position inside the transparent material at a predetermined depth Zsf from a surface of the transparent material in the optical axis direction; and irradiating the transparent material with the pulse laser beam having a pulse width of 1 ns to 100 ns inclusive and a beam diameter of 10 m to 150 m inclusive at the transfer position.

A device includes a first excitation light source that emits first excitation light, a second excitation light source that emits second excitation light, a wavelength converter that converts signal light of a first wavelength into signal light of a second wavelength according to the first excitation light, and a measurer that measures a frequency difference between the first excitation light and the second excitation light, wherein when an abnormality of the first excitation light is detected, the second excitation light source is adjusted so that a frequency of the second excitation light is aligned with a frequency of the first excitation light before the abnormality detection, based on the frequency difference before the abnormality detection, and the wavelength converter converts the signal light of the first wavelength into the signal light of the second wavelength according to the second excitation light, after adjusting the frequency of the second excitation light.