A laser projector steers a pulsed laser beam to form a pattern of stationary dots on an object, the pulsed laser beam having a periodicity determined based at least in part on a maximum allowable spacing of the dots and on a maximum angular velocity at which the beam can be steered, wherein a pulse width of the laser beam and a pulse peak power of the laser beam are based at least in part on the determined periodicity and on laser safety requirements.

An apparatus and method for calculating the frequency of the light.

Various example embodiments relate to active optical fibers and devices comprising active optical fibers. A section of an active optical fiber may comprise an active core doped with at least one rare-earth element. The active core may have a first refractive index and be configured to support a single mode operation of an optical signal. The section of the active optical fiber may further comprise at least one cladding layer having a second refractive index. The second refractive index may be less than the first refractive index. Birefringence of the active core may be less than 10.sup.-5. Fiber lasers and power amplifiers comprising the section of the active optical fiber are also disclosed.

A dry-type cleaning apparatus for wafers for dry cleaning of organic residues on a wafer surface includes a laser emitting laser light, an optical collimator receiving the laser light emitted from the laser and generating a first collimated laser light, an energy spreader uniformizing an energy distribution of the first collimated light received from the optical collimator, and a beam expander adjusting a diameter of the first collimated laser light passing through the energy spreader according to a diameter of a wafer to generate second laser light.

A laser system and method include a self-referencing shaper. A self-referencing pulse shaper is provided in an embodiment. Another aspect of a laser system includes at least one beam splitter splitting a reference beam from a working beam and a test beam, a delay optic delaying a reference laser beam, an active shaper, an interferometer, and a programmable controller. In another aspect, a method includes splitting an input laser pulse into a reference pulse and a shaping pulse, controlling phase and amplitude of the shaping pulse with an adjustable pulse shaper, creating an optical delay of the reference pulse, comparing a test pulse and the reference pulse after the controlling and delay, the laser system characterizing the input laser pulse and monitoring the laser system's own dispersion in a self-referenced manner, and correcting an output working laser pulse by adjusting the pulse shaper based on the comparing step.

A gas laser apparatus includes a chamber containing a laser gas, a pair of electrodes disposed within the chamber, a fan disposed within the chamber, a motor connected to a rotating shaft of the fan, and a rotating speed control unit configured to control a rotating speed of the fan based on a wear-out parameter of the pair of electrodes.

Systems and methods for measuring the angular position of a laser beam emitter using only distance measurements. What is physically measured is a feature that is affixed to the laser beam emitter and moves with it. Respective distances which are respective functions of the azimuth and zenith angles are measured using respective position encoders. In accordance with some embodiments, the respective distances are measured using linear encoders (optical or magnetic); in accordance with other embodiments, the respective distances are measured using laser interferometer-based encoders.

A laser system for amplifying laser light generated from a laser light source and emitting the laser light includes an optical element in an optical path of the laser light and transmits the laser light, a control device to control power to be supplied to the laser system, an imager to capture an image of the optical element, and an image processing circuitry to process the image of the optical element captured by the imager. The image processing circuitry in which reference images of the optical element corresponding to power information relating to the power are prepared in advance includes a comparison unit to compare a captured image of the optical element captured by the imager with a reference image selected by a reference image selection unit, the reference image corresponding to the power information at a time of image capturing by the imager.

A light beam measurement device includes: a polarization measurement unit including a first measurement beam splitter provided on an optical path of a laser beam and configured to measure a polarization state of the laser beam having been partially reflected by the first measurement beam splitter; a beam profile measurement unit including a second measurement beam splitter provided on the optical path of the laser beam and configured to measure a beam profile of the laser beam having been partially reflected by the second measurement beam splitter; and a laser beam-directional stability measurement unit configured to measure a stability in a traveling direction of the laser beam, while the first measurement beam splitter and the second measurement beam splitter are made of a material containing CaF.sub.2.

An electrodeless laser-driven light source includes a laser that generates a CW sustaining light. A pump laser generates pump light. A Q-switched laser crystal receives the pump light generated by the pump laser and generates pulsed laser light at an output in response to the generated pump light. A first optical element projects the pulsed laser light along a first axis to a breakdown region in a gas-filled bulb comprising an ionizing gas. A second optical element projects the CW sustaining light along a second axis to a CW plasma region in the gas-filled bulb comprising the ionizing gas. A detector detects plasma light generated by a CW plasma and generates a detection signal at an output. A controller generates control signals that control the pump light to the Q-switched laser crystal so as to extinguish the pulsed laser light within a time delay after the detection signal exceeds a threshold level.