Optical Setup; Figure 4-1 Vi30/40 Beam Ellipticity - Novanta vi30 User Manual

OPTICAL SETUP

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Figure 4-1 vi30/40 beam ellipticity.

Internal RF power supply
OEM vi30/40 lasers are driven by a compact radio frequency (RF) oscillator mounted in the laser
chassis. The 48 VDC input voltage is converted into a high-power RF signal using an RF power oscillator.
The output from the RF oscillator (nominally at 83.5 MHz) drives the laser directly by exciting carbon
dioxide (CO2) gas in the tube to produce lasing.
Control circuit
Sensors built into the OEM vi30/40 control board monitor the laser for conditions like under/ over
voltage, over temperature, and other faults that pose a risk of damage to the laser. The vi40 has
temperature broadcasting capability. (See Appendix) Additionally, laser operation is controlled by a
Laser Enable input.
Optical setup
After selecting a laser for a CO2 laser processing system, the two most crucial elements to consider are:
(1) beam 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 the same careful
attention to detail.
Beam delivery optics
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. Because the vi30/40 laser beam diverges
by 7 mm over each meter of distance traveled, the laser should be mounted a distance of 1.0–1.5 m (40–
60 in) away from the work area and no closer than 0.75 m (30 in) for optimum performance. Right angle
turning mirrors (beam benders) are often used in conjunction with the laser mounting position to obtain
this distance.