Search

Off-the-shelf beam analysis systems work very well in investigating and measuring collimated laser beam spatial profiles, focus spot spatial profiles, and the waist caustic. These standard systems have some shortcomings, however, related to viewing very small focus spot sizes at any wavelength, but especially at 10.6um. Another problem that these beam analysis systems can solve is alignment of optics and other components that can be damaged by high power beams if improperly set-up. This presentation will investigate the use of novel but simple imaging systems to allow in-depth analysis and real-time imaging of focus spot sizes from ∼10um to 100um at any laser wavelength, including 10.6um, allowing resolution of features as small as 0.25um. It will also investigate the use of low power pointing laser beams and artificial incoherent light to produce fine alignment and registration of optics and opto-mechanical components to high power laser beams. Examples will also employ ray-tracing information to validate the optical systems.Off-the-shelf beam analysis systems work very well in investigating and measuring collimated laser beam spatial profiles, focus spot spatial profiles, and the waist caustic. These standard systems have some shortcomings, however, related to viewing very small focus spot sizes at any wavelength, but especially at 10.6um. Another problem that these beam analysis systems can solve is alignment of optics and other components that can be damaged by high power beams if improperly set-up. This presentation will investigate the use of novel but simple imaging systems to allow in-depth analysis and real-time imaging of focus spot sizes from ∼10um to 100um at any laser wavelength, including 10.6um, allowing resolution of features as small as 0.25um. It will also investigate the use of low power pointing laser beams and artificial incoherent light to produce fine alignment and registration of optics and opto-mechanical components to high power laser beams. Examples will also employ ray-tracing information to validat...

Nd:YAG laser sources are extremely versatile in their ability to process materials by cutting, welding, heat treating, cladding and ablation. It is the one high power laser medium knownto date that can be used as a cw source, pulsed source, and q-switch source with our without frequency shifting. Each type of modulation has benefits in material processing, especially when viewing the decontamination of radioactive equipment. The ability to fiber deliver this laser light at high average powers is key to their use in industry and translates easily into the repair, decontamination and decommissioning of radioactive equipment. This paper will discuss the basic technology of laser sources and beam delivery as they apply to work on radioactive equipment.Nd:YAG laser sources are extremely versatile in their ability to process materials by cutting, welding, heat treating, cladding and ablation. It is the one high power laser medium knownto date that can be used as a cw source, pulsed source, and q-switch source with our without frequency shifting. Each type of modulation has benefits in material processing, especially when viewing the decontamination of radioactive equipment. The ability to fiber deliver this laser light at high average powers is key to their use in industry and translates easily into the repair, decontamination and decommissioning of radioactive equipment. This paper will discuss the basic technology of laser sources and beam delivery as they apply to work on radioactive equipment.

This paper presents the initial data obtained from an ongoing study that compares the performance of high power CO2 and Nd:YAG lasers in the full penetration lap welding of stainless steel materials suitable for automobile exhaust applications. The parameter of interest is the welding speed obtained for minimal undercut and dropout. Both cw and pulsed operation of CO2 and Nd:YAG lasers are being investigated. This initial set of data is on the weld speeds obtained for cw CO2 and cw and pulsed Nd:YAG lasers. The results show that the highest weld speeds were obtained with the pulsed Nd:YAG for the thicker material (3 mm) while the best performance for the thinner material (1.6 mm) was with the cw Nd:YAG. The comparison was carried out with consideration of the spot size used and no plasma suppression was used for the CO2 laser. The associated weld profile for each successful weld was also obtained.This paper presents the initial data obtained from an ongoing study that compares the performance of high power CO2 and Nd:YAG lasers in the full penetration lap welding of stainless steel materials suitable for automobile exhaust applications. The parameter of interest is the welding speed obtained for minimal undercut and dropout. Both cw and pulsed operation of CO2 and Nd:YAG lasers are being investigated. This initial set of data is on the weld speeds obtained for cw CO2 and cw and pulsed Nd:YAG lasers. The results show that the highest weld speeds were obtained with the pulsed Nd:YAG for the thicker material (3 mm) while the best performance for the thinner material (1.6 mm) was with the cw Nd:YAG. The comparison was carried out with consideration of the spot size used and no plasma suppression was used for the CO2 laser. The associated weld profile for each successful weld was also obtained.

The set-up and control of laser spot welding must be made more understandable if it is to reach its full potential in industry. Toward this end, a study was under-taken to better understand the variables that determine good-quality laser spot welds and the lasers to produce them. Peak power of the laser pulse was found to be the most influential parameter. For a particular optical spot size, it is the peak power that, once optimized, determines the weld quality. Focus-spot size can be held constant via fiber optic delivery so this variable is easily controlled. Software compensation to produce constant peak power during laser warm-up was found to allow 100% utilization of the laser. A laser with fiber delivery and warm-up compensation is the best system for spot welding.The set-up and control of laser spot welding must be made more understandable if it is to reach its full potential in industry. Toward this end, a study was under-taken to better understand the variables that determine good-quality laser spot welds and the lasers to produce them. Peak power of the laser pulse was found to be the most influential parameter. For a particular optical spot size, it is the peak power that, once optimized, determines the weld quality. Focus-spot size can be held constant via fiber optic delivery so this variable is easily controlled. Software compensation to produce constant peak power during laser warm-up was found to allow 100% utilization of the laser. A laser with fiber delivery and warm-up compensation is the best system for spot welding.