Abstract: Preferred embodiments of a purge gas port, laser beam attenuating input window, and laser shutter constitute subsystems of a UV laser optical system in which a laser beam is completely enclosed to reduce contamination of the optical system components. Purge gas is injected through multiple locations in a beam tube assembly to ensure that the optical component surfaces sensitive to contamination are in the flow path of the purge gas. The input window functions as a fixed level attenuator to limit photopolymerization of airborne molecules and particles. Periodically rotating optical elements asymmetrically in their holders reduces burn damage to the optics.

Abstract: A laser (126) and an AOM (10) are pulsed at substantially regular and substantially similar constant high repetition rates to provide working laser outputs (40) with variable nonimpingement intervals (50) without sacrificing laser pulse-to-pulse energy stability. When a working laser output (40) is demanded, an RF pulse (38) is applied to the AOM (10) in coincidence with the laser output (24) to transmit it to a target. When no working laser output (40) is demanded, an RF pulse (38) is applied to the AOM (10) in noncoincidence with the laser output (24) so it gets blocked. So the average thermal loading on the AOM (10) remains substantially constant regardless of how randomly the working laser outputs (40) are demanded. The AOM (10) can also be used to control the energy of the working laser output (40) by controlling the power of the RF pulse (38) applied. When the RF power is changed, the RF duration (44) of the RF pulse (38) is modified to maintain the constant average RF power.

Abstract: A laser (126) and an AOM (10) are pulsed at substantially regular and substantially similar constant high repetition rates to provide working laser outputs (40) with variable nonimpingement intervals (50) without sacrificing laser pulse-to-pulse energy stability. When a working laser output (40) is demanded, an RF pulse (38) is applied to the AOM (10) in coincidence with the laser output (24) to transmit it to a target. When no working laser output (40) is demanded, an RF pulse (38) is applied to the AOM (10) in noncoincidence with the laser output (24) so it gets blocked. So the average thermal loading on the AOM (10) remains substantially constant regardless of how randomly the working laser outputs (40) are demanded. The AOM (10) can also be used to control the energy of the working laser output (40) by controlling the power of the RF pulse (38) applied. When the RF power is changed, the RF duration (44) of the RF pulse (38) is modified to maintain the constant average RF power.

Abstract: A Q-switched, diode-pumped, solid-state (DPSS) laser (54) employs harmonic generation through nonlinear crystals (72) to generate UV light (74) for both link processing and target alignment. The type and geometry of the nonlinear crystals (72) are selected, and their temperatures are precisely controlled, to produce focused spot sizes with excellent beam quality for severing of IC fuses. A fraction of the laser output (56) can be utilized in a secondary target alignment system (50). An imaging optics module (52) may be employed to further enhance the shape quality of either or both of the secondary and primary beams. Each beam passes through a detection module (100) that measures the incident and reflected light. The two beams pass through a common combiner to facilitate calibration and alignment of the beams and subsequent link processing.

Abstract: A Q-switched, diode-pumped, solid-state (DPSS) laser (54) employs harmonic generation through nonlinear crystals (72) to generate UV light (74) for both link processing and target alignment. The type and geometry of the nonlinear crystals (72) are selected, and their temperatures are precisely controlled, to produce focused spot sizes with excellent beam quality for severing of IC fuses. A fraction of the laser output (56) can be utilized in a secondary target alignment system (50). An imaging optics module (52) may be employed to further enhance the shape quality of either or both of the secondary and primary beams. Each beam passes through a detection module (100) that measures the incident and reflected light. The two beams pass through a common combiner to facilitate calibration and alignment of the beams and subsequent link processing.