A laser apparatus includes: (A) a solid-state laser apparatus that outputs burst seed pulsed light containing a plurality of pulses; (B) an excimer amplifier that amplifies the burst seed pulsed light in a discharge space in a single occurrence of discharge and outputs the amplified light as amplified burst pulsed light; (C) an energy sensor that measures the energy of the amplified burst pulsed light; and (D) a laser controller that corrects the timing at which the solid-state laser apparatus is caused to output the burst seed pulsed light based on the relationship of the difference between the timing at which the solid-state laser apparatus outputs the burst seed pulsed light and the timing at which the discharge occurs in the discharge space with a measured value of the energy.

An object is to provide an optical amplifier with a cladding pumped configuration that improves amplification efficiency. The optical amplifier according to the present invention includes a pump light conversion fiber 11 that converts first pump light L1 with a first wavelength propagating in a cladding into second pump light L2 with a second wavelength, an amplification fiber 13 that is connected to the pump light conversion fiber 11 and optically amplifies signal light Ls with the second pump light L2 supplied to the cladding from the pump light conversion fiber 11, and an oscillator 12 that causes the second pump light L2 to be reflected on two reflectors 15 and to reciprocate within the claddings of the pump light conversion fiber 11 and the amplification fiber 13 to cause laser oscillation of the second pump light L2.

A light-emitting system includes an optical fiber, a first light source unit, a second light source unit, and a light-guiding member. The optical fiber includes a wavelength-converting portion containing a wavelength-converting element. The wavelength-converting element may be excited by excitation light to produce a spontaneous emission of light having a longer wavelength than the excitation light and may also be excited by an amplified spontaneous emission of light. The first light source unit makes the excitation light incident on the optical fiber. The second light source unit makes seed light, causing the wavelength-converting element that has been excited by either the excitation light or the amplified spontaneous emission of light to produce a stimulated emission of light, incident on the optical fiber. The light-guiding member guides the light coming from the optical fiber and lets the light emerge therefrom.

A Raman amplifier includes a first light source that outputs a primary pumping light, which propagates in a same direction as a propagation direction of a signal light, to an optical transmission line for Raman amplification, a second light source that outputs a secondary pumping light, which pumps and amplifies the primary pumping light and propagates in the same direction as the propagation direction, to the optical transmission line, and a control unit that controls a gain for the signal light by adjusting power of the secondary pumping light.

A laser transmitter including a waveform controller arranged to generate a waveform script having at least one of a pulse repetition frequency setting, a pulse duration setting, and a pulse amplitude pre-warp setting. The transmitter also includes an optical waveform generator arranged to: i) receive the waveform script, ii) generate pre-warped signal pulses based on the waveform script to compensate for gain distortion effects of a laser power amplifier, and iii) output the pre-warped signal pulses. The laser power amplifier is arranged to: i) receive the pre-warped signal pulses, ii) receive a continuous wave signal, and iii) output amplified signal pulses that maintain a substantially constant drive intensity at the input of a non-linear wavelength converter. The non-linear wavelength converter is arranged to receive the amplified signal pulses and emit wavelength-converted pulses.

A laser apparatus may include: a quantum cascade laser outputting, based on a supplied current, laser light at an oscillation start timing when a first delay time elapses from a current rising timing of the supplied current: an amplifier disposed in a laser light optical path, and selectively amplifying light of a predetermined wavelength to output the amplified laser light to a chamber including a plasma generation region into which a target is fed; and a laser controller controlling a third delay time, from an output timing of a laser output instruction to the current rising timing, to cause a laser light wavelength to be equal to the predetermined wavelength at an aimed timing when a second delay time elapses from the oscillation start timing, based on oscillation parameters including the first delay time, a supplied current waveform, and a device temperature of the quantum cascade laser.

Gain switched laser diode pulses are used as seed pulses for optical pulse generation. ASE is reduced by applying a prebias to the laser diodes at an amplitude less than that associated with a laser diode threshold. An electrical seed pulse having an amplitude larger than that associated with laser threshold is applied within about 10-100 ns of the prebias pulse. The resulting laser diode pulse can be amplified in a pumped, rare earth doped optical fiber, with reduced ASE.

A laser system including: A. a laser apparatus configured to output a pulse laser beam; B. an optical pulse stretcher including a delay optical path for expanding a pulse width of the pulse laser beam; and C. a phase optical element included in the delay optical path and having a function of spatially and randomly shifting a phase of the pulse laser beam. The phase optical element includes a plurality of types of cells providing different amounts of phase shift to the pulse laser beam and arranged irregularly in any direction.

An optical amplification device includes a first Raman amplifier outputs a first excitation light to a transmission line in a same direction as a signal light, and a second Raman amplifier outputs a second excitation light to the transmission line in an opposite direction to the signal light. The first Raman amplifier includes a first detector detects a first power of a first transmitted light transmitted through a first optical filter. The second Raman amplifier includes a second detector detects second power of a second transmitted light transmitted through a second optical filter. The first Raman amplifier stops output of the first excitation light when the first power is higher than a threshold. The second Raman amplifier stops output of the second excitation light when the second power is reduced from power of the first excitation light transmitted through the second optical filter.

A solid-state laser apparatus may include a first oscillator, a laser light generator, and a plurality of stages of fiber amplifiers. The first oscillator may be configured to output seed light. The laser light generator may be configured to output a pulsed laser light beam generated on a basis of the seed light. The plurality of stages of fiber amplifiers may be disposed in series in an optical path of the pulsed laser light beam, and may include a final stage fiber amplifier. The final stage fiber amplifier may be located in a final stage in the plurality of stages of fiber amplifiers, and may include a silica fiber doped with erbium and ytterbium. A value as a result of division of a cross-sectional area of the silica fiber by a fiber length of the silica fiber may be in a range from 0.7 nm to 1.64 nm both inclusive.