Novanta 32-1 Laser, Руководство пользователя

Страница: 30 / 58

OPTICAL SETUP PAGE | 30
Optical setup
After selecting a CO2 laser for your processing system, the two most important elements to consider are:
(1) delivery optics to transmit the beam to the work area; and (2) focusing optics to focus the beam onto
the part or material to be processed. Each element is crucial in the development of a reliable laser-based
material processing system and each element should be approached with same careful attention to detail.
Delivery optics
Divergence, or expansion, of the laser beam is important for materials processing since a larger beam
entering the focusing optic produces a smaller focused spot. Because the laser beam diverges slowly,
increasing 8 mm in diameter over every meter, 32-1 lasers should be mounted 1.0–1.5 m (40–60 in) away
from the work area. Right angle turning mirrors are often used in conjunction with the laser mounting
position to obtain this distance. Figure below shows how right-angle turning mirrors in a “flying optics”
setup create this longer beam path.
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 to the “flying optics”
setup shown below would substantially reduce beam divergence and any variance in beam diameter
caused by the changing optical path length. 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.
Figure 4-2 “Flying optics” beam path.
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 selecting based only on minimum spot size.
Caution: Possible Equipment Damage
Since 32-1 lasers are OEM products, they do not include cooling fans. Customers must provide some
type of air cooling to prevent the laser from overheating. See the cooling requirements at the end of
this chapter and cooling 101 located on our website.