The present disclosure discloses a double trigger type single pulse laser apparatus configured to suppress additional pulses to increase single pulse energy and improve stability of output as compared to a conventional single trigger type single pulse laser apparatus. According to the present invention, there is provided a single pulse laser apparatus including a resonator which has a first mirror, a second mirror, a gain medium, an electro-optic modulator and an acousto-optic modulator configured to respectively perform Q-switching and mode-locking, the single pulse laser apparatus including a first photodiode configured to measure a laser beam oscillated by the resonator.

An optical fiber laser device generates laser light by using an optical amplifying fiber as an amplification medium in a laser oscillator and includes: an optical outputting fiber configured to emit laser light to an outside; a return-light-attenuating portion configured to perform an attenuation process to return light propagating through at least the optical outputting fiber in a reverse direction of the laser light; a thermal conversion unit provided at the return-light-attenuating portion and configured to convert the return light into heat; a temperature-monitoring device configured to measure an increase in a temperature, of the return-light-attenuating portion, caused by the heat converted by the thermal conversion unit; and a control unit configured to decrease or stop an output of the laser light when the temperature measured by the temperature-monitoring device becomes a predetermined threshold temperature or higher.

A smart spool is configured to be optically coupled between a pumping light source and optical point-loss sources in an optical fiber transmission line. The smart spool comprises a probe signal transmitter that transmits an optical probe signal into the transmission line. An optical detector receives probe signals scattered in the transmission line. A loss-measuring device is coupled to the optical detector and operable to measure aggregate losses in the transmission line and report the aggregate losses to a network manager. The spool comprises a fiber of sufficient length to offset the aggregated losses to enable a distributed Raman amplifier to pump the transmission line. The smart spool prevents the distributed Raman amplifier from shutting down and allows the distributed Raman amplifier to achieve entitled gain by pumping the fiber in the spool.

An optical fiber laser device generates laser light by using an optical amplifying fiber as an amplification medium in a laser oscillator and includes: an optical outputting fiber configured to emit laser light to an outside; a return-light-attenuating portion configured to perform an attenuation process to return light propagating through at least the optical outputting fiber in a reverse direction of the laser light; a thermal conversion unit provided at the return-light-attenuating portion and configured to convert the return light into heat; a temperature-monitoring device configured to measure an increase in a temperature, of the return-light-attenuating portion, caused by the heat converted by the thermal conversion unit; and a control unit configured to decrease or stop an output of the laser light when the temperature measured by the temperature-monitoring device becomes a predetermined threshold temperature or higher.

A photodetection device including: first optical fibers; a second optical fiber; an optical combiner having: an end face connected to an end face of each of the first optical fibers; and another end face connected to an end face of the second optical fiber; a first photodetector that detects an intensity of light propagating through at least one of the first optical fibers; a second photodetector that detects Rayleigh scattering of light propagating through the second optical fiber; and a calculator that calculates the intensity of light propagating in a predetermined direction through the first optical fibers or the second optical fiber, from a result of detection by the first photodetector and a result of detection by the second photodetector.

Aspects of the present disclosure describe techniques for fast stabilization of multiple controller beams with continuous integrating filter. For example, a method is described for intensity stabilization of laser beams (e.g., ion controller beams) in a trapped ion system, where the method includes applying a linear array of laser beams to respective ions in a linear array of ions in a trap, performing, in response to the laser beams being applied, parallel measurements on the ions, the parallel measurements including multiple, separate measurements on each of the ions to identify fluctuations in intensity in the respective laser beams at each ion, and adjusting the intensity of one or more of the laser beams in response to fluctuations being identified from the parallel measurements. A corresponding system for intensity stabilization of laser beams in a trapped ion system is also described.

A laser device includes a master oscillator configured to output pulse laser light at a first discharge timing synchronized with a repetition frequency; an amplifier configured to amplify the pulse laser light by exciting, with a charge voltage at a second discharge timing, a laser medium through which the pulse laser light passes; and a processor configured to provide a command on the charge voltage to the amplifier based on a charge voltage command value provided from an exposure apparatus, set the second discharge timing by adding a delay time to the first discharge timing, and perform a process of changing the delay time and a process of correcting the charge voltage command value in accordance with a change of the repetition frequency.

A method of propagating a laser signal through an optical waveguide and a waveguide laser system provide a novel way of stabilizing the beam emitted by a fiber laser system above the mode instability threshold wherein the beat length of two or more interfering transverse modes of the laser signal in the optical waveguide is modulated in time.

The present disclosure relates a laser arrangement (1) and a method of the laser arrangement, arranged to output energy in the form of laser emission, for emitting controlled Q-switched laser emission. The laser arrangement comprises a gain medium (2) arranged to be excited when pumped, an optical resonator (3), an active Q-switch (4) arranged in the optical resonator, said active Q-switch (4) being controllable between at least a high loss state and a low loss state, and being arranged to introduce loss in the optical resonator to prevent lasing in the high loss state and to affect lasing minimally in the low loss state, a photo detector (5) arranged to detect the presence of a free running pulse (1) generated by the optical resonator and which occurs when a lasing threshold is reached and a processing circuitry (6) arranged to control (S4) of the state of the active Q-switch based on the detection of the free running pulse.

A smart spool is configured to be optically coupled between a pumping light source and optical point-loss sources in an optical fiber transmission line. The smart spool comprises a probe signal transmitter that transmits an optical probe signal into the transmission line. An optical detector receives probe signals scattered in the transmission line. A loss-measuring device is coupled to the optical detector and operable to measure aggregate losses in the transmission line and report the aggregate losses to a network manager. The spool comprises a fiber of sufficient length to offset the aggregated losses to enable a distributed Raman amplifier to pump the transmission line. The smart spool prevents the distributed Raman amplifier from shutting down and allows the distributed Raman amplifier to achieve entitled gain by pumping the fiber in the spool.