Novanta SYNRAD Pulstar p100, User Manual

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BEAM DELIVERY PAGE | 32
Beam Delivery
Divergence, or expansion, of the laser beam is important in materials processing since a larger beam
entering the focusing optic produces a smaller focused spot.
Expander/collimators are optical devices that reduce beam divergence while at the same time increasing
beam diameter by a selectable magnification factor. Adding an expander/collimator substantially
reduces beam divergence and any variance in beam diameter caused by the changing optical path
length in an XY (“flying optics”) table application. In fixed-length delivery systems where the laser is
positioned only one meter away from the focusing optic and a small spot size is required, an
expander/collimator is again the best solution to provide the required beam expansion before reaching
the focusing optic.
Focusing Optics
When selecting a focusing optic, the primary consideration should be material thickness and any vertical
tolerances that occur during final part positioning rather than making a selection based only on minimum
spot size. The chosen focal length should create the smallest possible focused spot while providing the
depth of field required for the material to be processed.
Optics are fragile and must be handled carefully, preferably by the mounting ring only. Be careful to
select optics that are thick enough to withstand the maximum assist gas pressure available for the
process. This is especially important in metal cutting applications using high-pressure assist gases.
Cleanliness is another important issue affecting performance; a dirty or scratched lens will underperform
and exhibit a vastly shortened lifetime. When the laser application requires air as an assist gas, use only
breathing quality air available in cylinders from a welding supply company. Compressed shop air
contains minute particles of oil and other contaminants that will damage optical surfaces. If compressed
shop air is the only choice available, it must be filtered to the specifications shown in the following table.
Laser tube
p100/150 lasers were developed using new technology patented by NOVANTA®. ’s patented “p”
technology, include RF components that are integrated within the laser body itself, eliminating the need
for external RF boxes and cables. The net result is a symmetrical laser beam from a small but powerful
laser capable of operating for many years with virtually no maintenance. ’s unique extruded aluminum
envelope offers excellent heat transfer, long gas life, and low operating costs in contrast to other laser
tube technologies. Besides being the vessel that maintains the lasing environment, the aluminum tube is
also the structural platform that integrates the laser’s optical, electrical, and cooling components.
p100/150 Technology
The p100/150’s peak pulse power takes materials processing a step further by allowing users to cut
faster and drill deeper through a variety of materials, with minimal heat affect zone and superior cut
edge quality.
Cooling
Heat generated by excited CO2 molecules is transferred to the bore walls by diffusion. Collected heat is
transferred to the water in the cooling tubes by conduction of the electrodes and aluminum envelope.
The coolant path is directed through corrosion-resistant copper alloy tubing to regulate temperature for
maximum stability. Operating the laser at coolant temperatures above 22 °C may result in decreased
performance and/or premature failure of electronic components.