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.

An electro-optic modulator (EOM) for altering an optical path length of an optical field is described. The EOM comprises first and second Brewster-angle cut nonlinear crystals having a first and second optical axis. The optical axes are orientated relative to each other such that when an optical field propagates through the nonlinear crystals it experiences no overall deviation. The nonlinear crystals are also arranged to be opposite handed relative to the optical field. The EOM has the advantage that its optical losses are lower when compared with those EOMs known in the art. In addition, the EOM can be inserted into, or removed from, an optical system without any deviation being imparted onto the optical field. This reduces the levels of skill and effort required on the part of an operator. The described method and apparatus for mounting the nonlinear crystals also suppresses problematic piezo-electric resonances within the nonlinear crystals.

Methods, systems and methods for reducing temporal coherence of laser systems are described. One example laser system includes a seed laser having a continuous wave output and operable at a first wavelength, a phase modulator positioned to receive laser light from the seed laser and to impart phase modulation to the seed laser. The laser system also includes an optical parametric amplifier positioned to receive phase-modulated laser light at one of its inputs and a pump laser light at another input, and to produce an output beam having spectral characteristics of the phase-modulated laser light that is amplified according to a temporal feature of the pump laser light. In the example laser system, an output of the optical parametric amplifier has a lower temporal coherence compared to the seed laser.

A radiation field generating system comprising an optical unit with an optical assembly which defines an optical path is provided, wherein the optical unit is operable in several different operation conditions and the optical assembly comprises at least one optical switching component with which switching between at least two different operation conditions of the several operation conditions can be performed.

A device and a method for measuring thermal load caused by excited state absorption in laser gain crystal are disclosed. Thermal focal lengths on the tangential and sagittal planes of the laser gain crystal are obtained by obtaining the threshold when the pump power is decreased, the optimal operating point, and cavity parameters of the single-frequency laser. Individual ABCD matrices of the laser gain crystal on the tangential plane and the sagittal plane are obtained based on thermal focal length. The thermal load corresponding to the threshold when the pump power is decreased, the ESA thermal load corresponding to the threshold when the pump power is decreased, and the ESA thermal load at the optimal operating point are obtained

In various embodiments, the concentration and deposition of siloxane materials within components of laser systems, such as laser resonators, is reduced or minimized utilizing mitigation systems that may also supply gas having low siloxane levels into multiple different components in series or in parallel.

A master oscillator configured as a seed laser for a laser optical module includes a reduced size, temperature controlled non-planar ring oscillator, a piezo-electric transducer mounted on the non-planar ring oscillator, a pump laser diode, and coupling optics configured to couple a laser output of the pump laser diode to an end face of the non-planar ring oscillator. The pump laser diode may operate as a single-mode pump.

A CW laser with a rotating ring gain element is disclosed. The ring is pumped at multiple locations and the laser generates a mid-IR output. Multiple pumped gain portions of the ring provide a power scaled output. The gain portions may be positioned in a single resonator cavity, in multiple resonator cavities, and in MOPA architectures with associated focusing, folding, and combining optical elements.

A laser apparatus includes: a laser oscillator that includes a mirror and emits a laser beam; and an external resonator that includes a nonlinear optical crystal that functions as a phase conjugate mirror. The phase conjugate mirror reflects the laser beam and produces a phase conjugate wave that reaches the mirror of the laser oscillator, and the mirror of the laser oscillator and the phase conjugate mirror cause laser oscillation such that a wavelength and a phase of the laser beam oscillated by the laser oscillation are automatically fixed.

A laser device includes: a traveling wave type resonator comprising a first mirror and a second mirror; and a laser medium disposed between the first mirror and the second mirror. The first mirror and the second mirror are disposed such that round-trip light that travels in round trips in the resonator has a focus inside the laser medium. The laser device is configured such that: excitation light incident on the resonator is superimposed on the round-trip light at the focus and narrowed to be thinner than the round-trip light, Z.sub.R×α<0.5 is satisfied, where Z.sub.R is a Rayleigh length of the excitation light and α is an absorption coefficient of the laser medium with respect to the excitation light, and a round-trip Gouy phase shift of the resonator has a value excluding 2π×n/m where m is an integer of less than 15 and n is an integer of equal to or less than m.