Abstract: A method for inter-substrate transfer of microelectronic devices includes applying a polymer coating to a top surface of a microelectronic device located on a first substrate, depositing an ultraviolet-transmissive adhesive on a second substrate, contacting the polymer-coated top surface of the microelectronic device to the adhesive to bond the microelectronic device to the second substrate, detaching the microelectronic device from the first substrate, and, while the bottom surface of the microelectronic device faces a third substrate, irradiating and ablating the polymer coating with ultraviolet laser light through the second substrate and the adhesive to transfer the microelectronic device from the second substrate to the third substrate via laser lift-off.

Abstract: A method for intracavity frequency conversion includes end-pumping a solid-state gain medium in a laser resonator with a pump laser beam to generate an intracavity laser beam circulating in the laser resonator, and frequency-converting a portion of the intracavity laser beam in a nonlinear crystal, located in the laser resonator, to generate a frequency-converted laser beam. The method controls the output power and at least one output beam parameter of the frequency-converted laser beam by adjusting (a) the pump power and (b) a resonator loss imposed on the intracavity laser beam. Taking advantage of both the pump laser beam and the intracavity laser beam contributing to thermal lensing in the gain medium, this control scheme is capable of controlling the output power and the output beam parameter(s) independently of each other.

Abstract: A device for shifting a nonlinear crystal arranged to frequency convert a laser beam includes an anchor, a mount for holding the nonlinear crystal, and two parallel flexures each interconnecting the mount and the anchor to cantilever the mount from the anchor. Each flexure extends in a first horizontal direction from the mount to the anchor. The two flexures being offset from each other in a vertical direction. The device also includes a transducer connecting between the anchor and the mount. Bending of the transducer shifts the position of the mount in the vertical direction, and the two parallel flexures cooperate to prevent rotation of the mount during shifting of the mount position induced by the transducer. This device provides an inexpensive and compact crystal-shifter solution with crystal-orientation stability equaling that of far more costly and bulky conventional translation stages.

Abstract: A device for shifting a nonlinear crystal arranged to frequency convert a laser beam includes an anchor, a mount for holding the nonlinear crystal, and two parallel flexures each interconnecting the mount and the anchor to cantilever the mount from the anchor. Each flexure extends in a first horizontal direction from the mount to the anchor. The two flexures being offset from each other in a vertical direction. The device also includes a transducer connecting between the anchor and the mount. Bending of the transducer shifts the position of the mount in the vertical direction, and the two parallel flexures cooperate to prevent rotation of the mount during shifting of the mount position induced by the transducer. This device provides an inexpensive and compact crystal-shifter solution with crystal-orientation stability equaling that of far more costly and bulky conventional translation stages.

Abstract: A device for thermally actuating a deformable mirror includes a monolithic block that includes a mirror plate having a front face forming or configured to support a mirror, a base, and a one-dimensional array of thermally expandable actuators. The thermally expandable actuators mechanically connect a rear face of the mirror plate to the base such that shape, tilt, and/or location of the front face depend on temperature of the thermally expandable actuators. The mirror plate, base, and thermally expandable actuators are defined by slits that span between opposite-facing top and bottom surfaces of the monolithic block. The monolithic block may be made of a metal and may be manufactured at relatively low cost by wire eroding the slits in a metal block, using a wire that passes through the metal block between its top and bottom surfaces.

Abstract: A system for resonantly enhanced frequency conversion includes a nonlinear crystal for frequency converting a pump laser beam, and mirrors forming a ring resonator for the pump laser beam such that a closed propagation path of the pump laser beam, inside the ring resonator, passes through the nonlinear crystal. The mirrors include an adaptive mirror, a curved-mirror pair positioned in a first segment of the propagation path spanning between the adaptive mirror and the nonlinear crystal, and an input coupler for coupling the pump laser beam into the ring resonator. The curved-mirror pair forms an imaging system having conjugate planes at the adaptive mirror and the nonlinear crystal. The input coupler is positioned in a second segment of the propagation path that spans between the adaptive mirror and the nonlinear crystal and does not include deflection by the curved-mirror pair.

Abstract: A layer on a substrate is laser annealed by pulses in a plurality of laser beams formed into a uniform line beam. The laser beams are partitioned into a first set of beams and a second set of beams. The second set of beams is incident onto the layer from a smaller range of angles than all of the beams combined. Pulses in the beams are synchronized such that pulses in the first set of beams are incident on the layer before pulses in the second set of beams. Pulses in the first set of beams melt the layer and pulses in the second set of beams sustain melting.

Abstract: A system for resonantly enhanced frequency conversion includes a nonlinear crystal for frequency converting a pump laser beam, and mirrors forming a ring resonator for the pump laser beam such that a closed propagation path of the pump laser beam, inside the ring resonator, passes through the nonlinear crystal. The mirrors include an adaptive mirror, a curved-mirror pair positioned in a first segment of the propagation path spanning between the adaptive mirror and the nonlinear crystal, and an input coupler for coupling the pump laser beam into the ring resonator. The curved-mirror pair forms an imaging system having conjugate planes at the adaptive mirror and the nonlinear crystal. The input coupler is positioned in a second segment of the propagation path that spans between the adaptive mirror and the nonlinear crystal and does not include deflection by the curved-mirror pair.

Abstract: A system for correcting the wavefront of a laser beam includes a beamsplitter for splitting off a fraction of the laser beam to be used as a diagnostic beam, a focusing element for bringing the diagnostic beam to a focus, a measurement subsystem for measuring sizes of the diagnostic beam at upstream and/or downstream locations with respect to a nominal location of the focus, and at least one adaptive optic, located upstream from the beamsplitter, for correcting the wavefront of the laser beam at least partly based on the measured sizes of the diagnostic beam at the upstream and/or downstream locations. The upstream and downstream locations correspond to mid-field locations in the laser beam as imaged by the focusing element. The system takes advantage of the sensitivity of the laser beam size to a waist location shift being greatest at one Rayleigh length from the nominal waist location.

Abstract: A device for thermally actuating a deformable mirror includes a monolithic block that includes a mirror plate having a front face forming or configured to support a mirror, a base, and a one-dimensional array of thermally expandable actuators. The thermally expandable actuators mechanically connect a rear face of the mirror plate to the base such that shape, tilt, and/or location of the front face depend on temperature of the thermally expandable actuators. The mirror plate, base, and thermally expandable actuators are defined by slits that span between opposite-facing top and bottom surfaces of the monolithic block. The monolithic block may be made of a metal and may be manufactured at relatively low cost by wire eroding the slits in a metal block, using a wire that passes through the metal block between its top and bottom surfaces.

Abstract: A beam homogenizer for transforming a beam of laser-radiation into a flat-top intensity distribution having brighter or darker edges comprises a first lens array, a second lens array, and a positive lens. The first lens array includes a plurality of lens elements that are separated by gaps having no optical power. Brighter or darker edges are produced by selecting a distance between the first and second lens arrays that is less than or greater than the focal length of lens elements in the second lens array.

Abstract: Fine-structure in the transverse mode of an excimer laser beam is minimized by having a plurality of resonator mirrors located at each end of a linear excimer laser. At one end, a highly-reflective end mirror and a partially-reflective end mirror are inclined at small angle with respect to each other. At the other end, two output-coupling mirrors are inclined at a small angle with respect to each other. This arrangement of resonator mirrors generates a composite laser beam that blurs any fine structure.

Abstract: An optic produces a beam of ultraviolet laser radiation from a beam of visible laser radiation and spatially separates the ultraviolet laser beam from the visible laser beam. The optic includes two crystals made of the same optically-nonlinear material that are contact bonded along a planar interface. One crystal has principle crystal axes that are oriented for type-I second-harmonic generation. The ultraviolet laser beam exits the optic through an uncoated surface of the other crystal. The principle crystal axes of the two crystals have different orientations and have reflection symmetry about the planar interface.

Abstract: An optic produces a beam of ultraviolet laser radiation from a beam of visible laser radiation and spatially separates the ultraviolet laser beam from the visible laser beam. The optic includes two crystals made of the same optically-nonlinear material that are contact bonded along a planar interface. One crystal has principle crystal axes that are oriented for type-I second-harmonic generation. The ultraviolet laser beam exits the optic through an uncoated surface of the other crystal. The principle crystal axes of the two crystals have different orientations and have reflection symmetry about the planar interface.

Abstract: Fine-structure in the transverse mode of an excimer laser beam is minimized by having a plurality of resonator mirrors located at each end of a linear excimer laser. At one end, a highly-reflective end mirror and a partially-reflective end mirror are inclined at small angle with respect to each other. At the other end, two output-coupling mirrors are inclined at a small angle with respect to each other. This arrangement of resonator mirrors generates a composite laser beam that blurs any fine structure.

Abstract: A beam homogenizer for transforming a beam of laser-radiation into a flat-top intensity distribution having brighter or darker edges comprises a first lens array, a second lens array, and a positive lens. The first lens array includes a plurality of lens elements that are separated by gaps having no optical power. Brighter or darker edges are produced by selecting a distance between the first and second lens arrays that is less than or greater than the focal length of lens elements in the second lens array.

Abstract: An optical ring-resonator converts visible wavelength radiation to ultraviolet wavelength radiation by frequency-doubling the visible wavelength radiation in an optically nonlinear crystal. The resonator includes an uncoated birefringent out-coupling prism. The visible wavelength radiation passes through faces of the prism at a Brewster-angle. Ultraviolet wavelength radiation enters the prism, is totally internally reflected, directed out of the prism at a Brewster-angle, and exits the ring-resonator as output radiation.

Abstract: This disclosure provides methods and apparatuses which advantageously stabilize beam parameters and elongate crystal lifetime. In one aspect, a UV laser apparatus includes a non-linear crystal, a laser source, a beam-crystal displacer, a beam parameter monitor, and a laser control unit. The laser source directs a source beam to the non-linear crystal to produce a UV beam and the beam-crystal displacer shifts the non-linear crystal relative to the source beam at a plurality of shift speeds. The beam parameter monitor measures the UV beam and outputs a measurement of a beam parameter. The laser control unit: receives the measurement; determines, based on the measurement, an adjustment in shift speed that steers the beam parameter toward a target value; and outputs the adjustment to the beam-crystal displacer.

Abstract: In a laser line projection apparatus, six spaced-apart unpolarized laser-beams are plane-polarized with low loss by a combination of a thin-film polarizer, a reflector, and two polarization rotators. Two beams are polarized in each of three polarization-orientations. Two of the polarization-orientations are orthogonally aligned with each other in P and S orientations. The other polarization-orientation is non-orthogonally aligned in an intermediate orientation. The beams are intensity-homogenized and projected into a line of radiation. Any point on the line of radiation is formed from rays with an angular distribution of polarization-orientation from S to P through the intermediate orientation and back to S through the intermediate orientation.

Abstract: Excimer laser annealing apparatus includes and excimer laser delivering laser-radiation pulses to a silicon layer supported on a substrate translated with respect to the laser pulses such that the consecutive pulses overlap on the substrate. The energy of each of the laser-radiation pulses is monitored, transmitted to control-electronics, and the energy of a next laser pulse is adjusted by a high-pass digital filter.