
B–70114EN/04
4. FUNCTIONS
103
The following describes the details of each component of the FANUC
LASER C series. Fig. 4.2 (a) to (l) show the internal structure.
(1) Resonator
The resonator consists of an output mirror, rear mirror, folding
mirrors, discharge tubes, power sensor unit, etc. It converts electrical
energy first to laser gas, then to optical energy (10.6–mm
single–wavelength laser beam).
(2) Output mirror
A transmitting/reflecting mirror which outputs the laser beam after
it has been amplified. The output mirror consists of a ZnSe (zinc
selenide) substrate, coated with dielectric. ZnSe is tightly toxic. Be
particularly careful, therefore, when handling the output mirror.
(3) Rear mirror
A reflecting mirror consisting of a Ge (germanium) substrate, coated
with dielectric. Having a high reflectance of 99.5%, the rear mirror
is used to reflect the laser beam within the resonator while
transmitting 0.5% of the laser light so that the beam can be monitored
externally.
(4) Folding mirror
The folding mirror, consisting of a 45° block and a gold–coated Si
(silicon) substrate, is used to divert the laser beam through 90°. It
also linearly polarizes the laser beam.
(5) Discharge tube
A pair of Ag (silver) electrodes are metallized on the surface of a
hollow quartz glass pipe. A high–frequency discharge between these
electrodes injects electrical energy into the laser gas. Each electrode
is coated with ceramic, preventing it from degrading and thus
improving system reliability.
(6) Power sensor
An optical sensor which detects the intensity of the laser beam,
transmitted through the rear mirror, thus enabling monitoring of the
laser output level.
(7) Gas circulating system
A gas circulating path including a turbo blower, heat exchangers, and
circulating pipes, which supplies and exhausts laser gas to and from
the discharge tubes at high speed.
(8) Turbo blower
During laser oscillation, the laser gas pressure is 100 to 700 (1330 to
9310 Pa) when DGN. The turbo blower circulates this
rough–vacuum gas at high speed (up to 200 m/s within the discharge
tubes) without contaminating the gas.
(9) Heat exchanger (inlet)
Heat exchanger used to cool the laser gas that has been heated by
discharge, before it is drawn into the turbo blower.
(10)Heat exchanger (outlet)
Heat exchanger used to cool the laser gas that has been heated by
compression in the turbo blower, before being forced into the
discharge tubes.
4.2
COMPONENT
DETAILS