A titanium-sapphire laser apparatus may include a continuous wave oscillation laser unit, an amplification oscillator, a pulsed laser unit, an error detector, an error controller, and an optical path length corrector. The amplification oscillator may include an optical resonator and a titanium-sapphire crystal that is provided in an optical path in the optical resonator. The error detector may be provided in an optical path of leak light of seed light from the optical resonator, and may detect an optical path length error between an optical path length in the optical resonator and a positive integer multiple of a wavelength of the seed light and output an optical path length error signal. The optical path length corrector may vary the optical path length in the optical resonator on a basis of a signal resulting from adding a correction value to the optical path error signal.

An apparatus is described. The apparatus comprises a downstream wavelength selective switch having an input port, an optical path operable to carry an optical signal, an optical source providing amplified spontaneous emission (ASE) light, an optical switch having a first input coupled to the optical path, a second input coupled to the optical source and receiving the ASE light, and an output coupled to the input port of the downstream wavelength selective switch. The optical switch couples either the first input or the second input to the output. Further included is a photodiode operable to monitor the optical signal, detect an optical loss of signal of the optical signal, and output a switch signal to the optical switch such that the optical switch couples the second input receiving the ASE light to the output whereby the ASE light is directed to the input port of the downstream wavelength selective switch.

A method of emitting wavelength-swept light includes controlling either one or both of magnitudes and on/off timings of currents to be applied to a first gain medium of a first optical generator and a second gain medium of a second optical generator to control an intensity and a wavelength region of each of first wavelength-swept light and second wavelength-swept light; generating the first wavelength-swept light having a first center wavelength based on the current applied to the first gain medium of the first optical generator; generating the second wavelength-swept light having a second center wavelength based on the current applied to the second gain medium of the second optical generator; and emitting output wavelength-swept light by coupling the first wavelength-swept light and the second wavelength-swept light.

An example laser apparatus of the disclosure may include an oscillator capable of outputting a laser beam, a slab optical amplifier capable of amplifying the laser beam outputted by the oscillator by passing the laser beam through an optical amplification region shaped like a slab and outputting the amplified laser beam, and a mirror disposed on an optical path of the laser beam to enter the slab optical amplifier or the amplified laser beam outputted from the slab optical amplifier, the mirror being movable in a direction parallel to a plane where the laser beam travels in the slab optical amplifier.

The invention relates to a discoidal or cuboidal solid body for a laser amplification system of a solid-state laser, which solid body contains at least one laser-active material, has an upper side defining an upper side plane and a lower side defining a lower side plane, wherein the upper side plane and the lower side plane are inclined in relation to each other and enclose an angle of inclination, wherein the lower side is provided with a first reflective coating, wherein the upper side is provided with a second reflective coating, and wherein at least one of the upper side and the lower side has at least one optical input coupling opening for input coupling at least one of a seed laser radiation field and a pump laser radiation field into the solid body between the first and the second reflective coating.

A directed energy weapon includes a number of laser units, each including a fiber laser generating an output beam with a power of at least 1 kW from a fiber, an objective lens arrangement for focusing the output beam into a focused beam directed towards a target, and a fine adjustment mechanism fir adjusting a direction of the focused beam. A beam deflector arrangement is deployed to deflect a portion of the focused beam from each laser unit as a deflected beam in a direction in predefined relation to a direction of the focused beam. An angle sensing unit generates an output indicative of a current direction of said deflected beam for each of said laser units. A controller actuates the fine adjustment mechanisms based on the output from the angle sensing unit to maintain a desired relative alignment between directions of the focused beams.

Devices and methods for generating EUV light are disclosed. The device comprises an oscillator having an oscillator cavity length, L.sub.o, and defining an oscillator path and a multi-pass optical amplifier coupled with the oscillator to establish a combined optical cavity including the oscillator path, the combined cavity having a length, L.sub.combined, where L.sub.combined=(N+x)*L.sub.o, where “N” is an integer and “x” is a number between 0.4 and 0.6. The amplifier comprises a polarization discriminating optic inputting light traveling along a first beam path from the oscillator and having substantially a first linear polarization into the amplifier and outputting light having substantially a linear polarization orthogonal to the first polarization out of the amplifier along a second beam path.

A system includes N master oscillators to generate N master oscillator driving signals. The system includes N splitters to split each of the N master oscillator signals into M coherent signals with M being a positive integer greater than one. A modulator and fiber amplifier stage adjusts the relative phases of the M coherent signals and generates M×N amplified signals. The M×N amplified signals are aggregated into M clusters of N fibers. The system includes M spectral beam combination (SBC) modules to combine each of the M clusters. Each SBC module combines the M×N amplified signals at N wavelengths and generates M tiled output beams. Each SBC module employs a single dimensional (1D) fiber optic array to transmit one cluster of N amplified signals from the M signal clusters and generates one tiled output beam of the M tiled output beams.

Laser and inspection systems that generate laser output light at sub-200 nm wavelengths using fundamental light at approximately 1064 nm. A second harmonic generator module generates second harmonic light directed to both an optical parametric (OP) module, which generates down-converted signal (idler light), and to a fifth harmonic generator module, which generates fifth harmonic light. The OP module includes an optical parametric oscillator that is configured to generate the idler signal at approximately 0.5 times the fundamental frequency. The idler light and fifth harmonic light are then mixed by a frequency mixing module to generate the laser output light having an output frequency equal to approximately 5.5 times the fundamental frequency.

A fiber coupled modular laser system comprises a laser oscillator, at least one fiber pre-amplifier, and at least one free space solid state power amplifier. The output of the laser oscillator is fiber coupled with the input of the at least one fiber pre-amplifier or the at least one free space solid state power amplifier. The output or the input of the at least one fiber pre-amplifier is fiber coupled with the input or the output of the at least one free space solid state power amplifier.