A method for forming an article includes providing a material having a first material property; forming a melt pool by exposing the material to an optical beam having at least one beam characteristic, wherein the melt pool has at least one melt pool property determinative of a second material property of the material; and modifying the at least one beam characteristic in response to a change in the melt pool property.

An optical beam delivery device formed of optical fibers that are configured to produce an output exhibiting an intensity distribution profile having non-zero ellipticity includes a first length of fiber through which an incident optical beam having beam characteristics propagates and which has a first refractive index profile (RIP). The first RIP enables, in response to an applied perturbation, modification of the beam characteristics of the optical beam to form an adjusted beam having modified beam characteristics relative to the beam characteristics of the optical beam. A second length of fiber is coupled to the first length of fiber and formed with a set of one or more confinement regions that define a second RIP and confine at least a portion of the adjusted beam to generate, at an output of the second length of fiber, an intensity distribution profile having non-zero ellipticity.

A method for forming an article includes providing a material having a first material property; forming a melt pool by exposing the material to an optical beam having at least one beam characteristic, wherein the melt pool has at least one melt pool property determinative of a second material property of the material; and modifying the at least one beam characteristic in response to a change in the melt pool property.

According to one embodiment, an illumination optical apparatus comprises: a light splitting device which splits the beam into a plurality of beams with respective polarization states different from each other; a spatial light modulation device which is arranged on at least one of a first optical path in which a first beam out of the plurality of beams travels and a second optical path in which a second beam out of the plurality of beams travels, and which has a plurality of optical elements arranged two-dimensionally and driven individually; and a control device which controls the spatial modulation device to combine the first beam and the second beam at least in part.

The invention relates to an optical device (1) for enhancing the resolution of an image or for reducing speckle noise.

An apparatus for generating extreme ultraviolet (EUV) radiation includes a droplet generator configured to generate target droplets. An excitation laser is configured to heat the target droplets using excitation pulses to convert the target droplets to plasma. A deformable mirror is disposed in a path of the excitation laser. A controller is configured to adjust parameters of the excitation laser by controlling the deformable mirror based on a feedback parameter.

Disclosed herein are methods, apparatus, and systems for providing an optical beam delivery system, comprising an optical fiber including a first length of fiber comprising a first RIP formed to enable, at least in part, modification of one or more beam characteristics of an optical beam by a perturbation assembly arranged to modify the one or more beam characteristics, the perturbation assembly coupled to the first length of fiber or integral with the first length of fiber, or a combination thereof and a second length of fiber coupled to the first length of fiber and having a second RIP formed to preserve at least a portion of the one or more beam characteristics of the optical beam modified by the perturbation assembly within one or more first confinement regions. The optical beam delivery system may include an optical system coupled to the second length of fiber including one or more free-space optics configured to receive and transmit an optical beam comprising the modified one or more beam characteristics.

A method of processing by controlling one or more beam characteristics of an optical beam may include: launching the optical beam into a first length of fiber having a first refractive-index profile (RIP); coupling the optical beam from the first length of fiber into a second length of fiber having a second RIP and one or more confinement regions; modifying the one or more beam characteristics of the optical beam in the first length of fiber, in the second length of fiber, or in the first and second lengths of fiber; confining the modified one or more beam characteristics of the optical beam within the one or more confinement regions of the second length of fiber; and/or generating an output beam, having the modified one or more beam characteristics of the optical beam, from the second length of fiber. The first RIP may differ from the second RIP.

A light source apparatus is provided to include a plurality of laser light sources that emits color light rays having multiple wavelength bands. The light source apparatus further includes a plurality of dichroic mirrors that combines the color light rays and outputs a combined color light rays; and a dynamic diffusion plate that diffuses incident light rays from the plurality of dichroic mirrors so as to remove speckles specific to laser beams. One of the dichroic mirrors is a dichroic mirror that reflects blue light, and each of the plurality of laser light sources includes a blue laser light source. The blue laser light source generates a P-polarized short-wavelength-band laser beam, and an S-polarized long-wavelength-band laser beam having a wavelength longer than a wavelength of the short-wavelength-band laser beam.

Example embodiments provide systems and methods for correcting non-uniformities of a light beam generated by a multi-emitter light source. In some embodiments a phase modulator displays patch lenses to correct for the non-uniformities. In some embodiments each region of the phase modulator is illuminated by a beam generated by one emitter of the multi-emitter light source. Such region of the phase modulator may display a patch lens for correcting non-uniformities in the corresponding beam which illuminates the region.