2.INTERNAL STRUCTURE B-70315EN/02
- 44 -
(1) Output coupler
A transmitting/reflecting mirror, which outputs the laser beam
after it, has been amplified inside the resonator. The output
coupler consists of a ZnSe (zinc selenide) substrate with a
curvature on the surface and coated with dielectric. ZnSe is
highly toxic. Be particularly careful, therefore, when handling
the output coupler.
(2) Rear mirror
A reflecting mirror consisting of a Ge (germanium) substrate
coated with dielectric. The rear mirror is used to reflect the laser
beam within the resonator while transmitting part of the laser
light to the outside to obtain the monitor light for laser output
measurement.
(3) Folding mirror
A mirror with a Si (silicon) substrate coated with dielectric to
reflect the laser beam.
It linearly polarizes the laser beam. A system equipped with an
optional antireflective mirror (ATFR) is available.
The antireflective mirror consists of a copper substrate with
coating. (ATFR means Absorbing Thin Film Reflector.)
(4) Discharge tube
A pair of Ag (silver) electrodes is metallized on the surface of a
hollow quartz glass tube. 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.
(5) Trigger electrode
This electrode is capable of pre-discharging outside the laser
oscillation area so that the laser output becomes completely zero
when the beam is off.
(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) Oil mist decomposing element
This element is capable of decomposing the organic matter that
gets into the laser gas circulating system, with photocatalytic
effect, using the ultraviolet rays generated from the discharge
tubes.
(8) Laser power supply
This power supply outputs high-frequency power (2 MHz)
according to a specified output with commands from the CNC
and supplies it to the discharge tubes via the matching box.