A Laser system is disclosed which comprises a pump, wherein the laser system is adapted to be operated in pulsed operation so that at least one individual pulse of a temporally limited pulse duration (T.sub.0) is generated, wherein the pulse ablates a material such that a debris cloud forms above the ablated material. Further, the pump power of the pump is modulated in such a way that the following three conditions are fulfilled: (1) the intensity of the pulse oscillates between maximum values and minimum values during the pulse duration, wherein the laser pulse comprises a plurality of intensity maxima I.sub.max which occur at times {T.sub.i, i=1, . . . N}; and a plurality of intensity minima I.sub.min which occur at times {t.sub.k, k=1, . . . (N1)}, wherein the intensity does not vanish at the intensity minima; (2) the intensity oscillations of the laser pulse induce oscillations of the size of the debris cloud so that, during the pulse duration (T.sub.0), there are at least two maxima of the size of the debris cloud which occur at times {T.sub.j, j=1, . . . M} and which are located in between two intensity maxima of the laser pulse; and (3) at least 70 percent of the maxima of the size of the debris cloud occur near an intensity minimum of the pulse such that, for at least 70 percent of the maxima of the size of the debris cloud, the intensity of the pulse I(T.sub.j) at the time of the maximum of the size of the debris cloud is smaller than I.sub.min(t.sub.k)+0.5[I.sub.max(T.sub.i)I.sub.min(t.sub.k)], wherein I.sub.min(t.sub.k) is the intensity minimum of the pulse which is closest to the maximum of the size of the debris cloud at time T.sub.j and I.sub.max(T.sub.i) is the intensity maximum of the pulse which is closest to the maximum of the size of the debris cloud at time T.sub.j.

A pulsed laser device includes: a semiconductor laser device that outputs laser light having a single wavelength; a semiconductor optical amplifier that receives the laser light output from the semiconductor laser device and amplifies the laser light to output; and a semiconductor-optical-amplifier driver that supplies a pulse-modulated semiconductor-optical-amplifier driving current to the semiconductor optical amplifier.

A laser device for skin treatment includes: a laser generating unit including a diode laser for generating a pulse capable of being varied to a pulse width of 100 picoseconds (ps) to 2000 ps by a dedicated driver having a rising time of 100 ps or less and a pulse width adjustment unit for adjusting a width of the pulse generated by the diode laser, the laser generating unit configured to generate a single or a plurality of pulses; and a laser amplifying unit including a pumping lamp and a single or a plurality of amplification mediums having a rod structure for absorbing light energy from the pumping lamp, wherein, in the laser amplifying unit, a pulse supplied from the laser generating unit passes through at least one of the single or a plurality of amplification mediums a plurality of times inward from the outside and is gradually amplified.

A laser system generates laser pulses having a determined carrier-envelope-offset, CEO. The laser system includes a Cr-doped II-VI based laser oscillator system having a resonator cavity, which emits laser pulses having a peak power of at least 0.75 MW. The laser system further includes a nonlinear optical element for spectrally broadening at least a part of the emitted laser pulses irradiated onto the nonlinear optical element to provide the laser pulses with octave-spanning spectral components, and a frequency-doubling element for generating second harmonic spectral components of at least a part of the octave-spanning spectral components. In addition, the laser system includes an f-2f-interferometry device for generating a beating signal of at least a part of the overlapping spectral components exiting the frequency-doubling element and interfering with each other at the f-2f-interferomtry device and for determining and/or controlling the CEO of the emitted laser pulses based on the beating signal.

An optical pulse generation device includes an optical resonator of mode-locked type, a light source, and a waveform controller. The optical resonator includes an optical amplification medium and generates, amplifies, and outputs laser light. The light source is optically coupled to the optical resonator and supplies excitation light to the optical amplification medium. The waveform controller is arranged in the optical resonator, and controls a time waveform of the laser light within a predetermined period to convert the laser light into an optical pulse train including two or more optical pulses within a period of the optical resonator. The optical resonator amplifies the optical pulse train after the predetermined period and outputs the optical pulse train having amplified as the laser light.

Disclosed is an optical-fibre laser system including an injector generating a source pulse, a spectro-temporal shaping module, at least one final optical-fibre amplifier having a length less than ten metres, the final amplifier being suitable for receiving a filtered pulse from a spectral filter and generating an amplified pulse with controlled chirp, a volume compressor which has a predetermined linear chirp and is suitable for receiving the amplified pulse and forming a compressed pulse having a duration of less than 3 picoseconds and an electronic unit for adjusting the duration of the compressed pulse, the electronic duration adjusting unit being formed by adjusting the energy of the source pulse and/or the amplified pulse, the duration of the compressed pulse being tunable according to the energy setting.

A laser system may include a controller configured to direct a plurality of temporally spaced-apart electrical pulses to a device that optically pumps a lasing medium, and a lasing medium configured to output a quasi-continuous laser pulse in response to the optical pumping. The plurality of temporally spaced-apart electrical pulses may include (a) a first electrical pulse configured to excite the lasing medium to an energy level below a lasing threshold of the lasing medium, and (b) multiple second electrical pulses following the first electrical pulse. The quasi-continuous laser pulse is output in response to the multiple second electrical pulses.

A laser system according to the present disclosure includes: a laser apparatus configured to emit a laser beam; a transmission optical system disposed on a path between the laser apparatus and a target supplied into an EUV chamber in which EUV light is generated; a reflection optical system configured to reflect, toward the target, the laser beam from the transmission optical system; a first sensor configured to detect the laser beam traveling from the laser apparatus toward the reflection optical system; a second sensor configured to detect return light of the laser beam reflected by the reflection optical system and traveling backward to the laser apparatus; and a control unit configured to determine that the reflection optical system is damaged when no anomaly of the laser beam is detected and a light amount of the return light exceeds a predetermined light amount value.

A laser system may include a controller configured to direct a plurality of temporally spaced-apart electrical pulses to a device that optically pumps a lasing medium, and a lasing medium configured to output a quasi-continuous laser pulse in response to the optical pumping. The plurality of temporally spaced-apart electrical pulses may include (a) a first electrical pulse configured to excite the lasing medium to an energy level below a lasing threshold of the lasing medium, and (b) multiple second electrical pulses following the first electrical pulse. The quasi-continuous laser pulse is output in response to the multiple second electrical pulses.

A divided-pulse laser regeneration amplification apparatus includes: a signal light coupling component including a first half-wave plate, a first polarization beam splitter, a first Faraday rotator and a second half-wave plate placed in sequence; and a divided-pulse laser regeneration amplification component including a second polarization beam splitter and a third reflector, the second polarization beam splitter is adjacent to the second half-wave plate and is in a same column as the third reflector and the second half-wave plate; a first quarter-wave plate, a Pockels cell and a first reflector are successively arranged on a first side of the second polarization beam splitter, and a third half-wave plate, a first pulse polarization separation component and a first non-linear pulse amplification component are successively arranged on a second side of the second polarization beam splitter.