A laser irradiation method of irradiating, with a pulse laser beam, an irradiation object in which an impurity source film is formed on a semiconductor substrate includes: reading fluence per pulse of the pulse laser beam with which a rectangular irradiation region set on the irradiation object is irradiated and the number of irradiation pulses the irradiation region is irradiated, the fluence being equal to or larger than a threshold at or beyond which ablation potentially occurs to the impurity source film when the irradiation object is irradiated with pulses of the pulse laser beam in the irradiation pulse number and smaller than a threshold at or beyond which damage potentially occurs to the surface of the semiconductor substrate; calculating a scanning speed Vdx; and moving the irradiation object at the scanning speed Vdx relative to the irradiation region while irradiating the irradiation region with the pulse laser beam at the repetition frequency f.

A supporting member supports a peeled end portion formed at an end portion in longitudinal direction representing first direction of an optical fiber, the optical fiber including: a core wire including a core and a cladding; and a jacket configured to enclose the core wire, the jacket being removed at the peeled end portion to expose the core wire. The supporting member includes: a first member; a second member fixed to the first member; a housing portion provided between the first member and the second member, the housing portion extending along the peeled end portion and being configured to house the peeled end portion; and a processed member housed in the housing portion and provided around the peeled end portion, the processed member being configured to cause transmission or scattering of light leaking from the peeled end portion.

A fiber applied to an optical amplifier, where the fiber includes a rare earth-doped core and a cladding. The core includes a gain equalization unit. The core is configured to separately amplify optical signals of all wavelengths in a received multiplexing wave. The gain equalization unit is configured to equalize gains of the optical signals of all the wavelengths, such that gains of optical signals that are of all the wavelengths and that are transmitted from an egress port of the fiber all fall within a preset range, The gain of the optical signal of each wavelength in the optical signals of all the wavelengths is determined based on a ratio of power of an amplified optical signal to power of the unamplified optical signal.

Apparatus include a mode-locked laser cavity configured to produce a mode-locked output beam, wherein the laser cavity includes a gain medium situated in the laser cavity and an intracavity optical coating filter situated in the laser cavity to receive an intracavity beam, wherein the intracavity optical coating filter has an attenuation profile configured to suppress laser oscillation over a selected portion of the gain bandwidth of the gain medium and to increase a bandwidth of the mode-locked output beam based on the suppression. Related optical coatings are disclosed. Methods of arranging coatings and reducing pulse duration are also disclosed.

A laser system having a multi-pass amplifier system which includes at least one seed source configured to output at least one seed signal having a seed signal wavelength, at least one pump source configured to output at least one pump signal, at least one multi-pass amplifier system in communication with the seed source and having at least one gain media, a first mirror, and at least a second mirror therein, the gain media device positioned between the first mirror and second mirror and configured to output at least one amplifier output signal having an output wavelength range, the first mirror and second mirror may be configured to reflect the amplifier output signal within the output wavelength range, and at least one optical system may be in communication with the amplifier system and configured to receive the amplifier output signal and output an output signal within the output wavelength range.

Integrated wavelength selectors are described. The wavelength selector may include silicon nitride ring resonator disposed vertically between a heater and a temperature sensor. The temperature sensor may be formed of silicon in some embodiments. The wavelength selector may be coupled to the output port of a tunable laser, or may be disposed within a laser cavity.

A display device includes a laser irradiation device and a control device. The laser irradiation device is configured to irradiate an irradiation point located at a display position in air, with a laser beam having a wavelength equal to or larger than 380 nm and equal to or smaller than 780 nm and produce plasma at the display position. The control device is configured to control intensity of the laser beam emitted from the at least one laser irradiation device so that a relationship between intensity of plasma light emitted from the plasma at the display position and intensity of scattered light produced from the laser beam and scattered by the plasma becomes a predetermined relationship to display a color pixel.

A compact laser source and a single sideband modulator used therein is disclosed. The compact laser source includes a seed laser and one or more channels, with each channel generating one or more output laser beams having corresponding different wavelengths. The compact laser source can be formed in whole or in part on a single optical motherboard to thereby minimize space and power requirements. By employing the disclosed single sideband modulator, harmonics in the generated output laser beams can be minimized. The compact laser source finds application in an atom interferometer (AI) system, which may be used to measure gravity, acceleration, or rotation of the AI system.

The method comprises A method includes steps for creating at least two replicas of an input pulse to be characterised, varying the relative amplitude of the two replicas within a range, creating a nonlinear signal at each case of said amplitude variation, measuring the spectra of the nonlinear signals and recovering the spectral amplitude and phase of the input pulse with a proper algorithm. The system includes a replicator for creating at least two replicas of the input pulse and varying their relative amplitude within a range of relative amplitudes, a nonlinear medium, which obtains a nonlinear signal for each relative amplitude, and an analyzer, associated to the nonlinear signal for measuring and characterising spectrally each nonlinear signal.

A method for amplifying an ultrashort laser pulse includes: a) stretching the ultrashort laser pulse in time, b) amplifying the time-stretched laser pulse, c) compressing the amplified time-stretched laser pulse, with at least one gain phase contribution selected from a group consisting of a gain dynamics phase contribution of the laser pulse that emerges as a change in a nonlinear phase on account of gain dynamics in step b), a gain bandwidth phase contribution of the laser pulse that emerges as a change in the nonlinear phase on account of a gain bandwidth in step b), and a combination thereof, being compensated by virtue of d) an additional phase contribution being imparted on the laser pulse prior to step c) and/or e) a spectrum of the laser pulse being changed, in such a way that the at least one gain phase contribution is compensated after step c).