Excimer Lasers
The
Excimer laser is a gas laser where
the active medium is the combination of a halide gas like
Hydrogen Chloride (HCl) or Fluorine (F) with a rare gas like
Argon (Ar), Krypton (Kr) or Xenon (Xe); in the excited state
these form a metastable compound called “excited
dimer”.
The resulting laser light has a wavelength of 0.15-0.35um
(ultraviolet range); the beam is transferred to the point of
use through mirrors and lenses or an optical fiber, making it
very flexible.
The halide/rare
gas compound, typically in a mixture with Helium or Neon as a
buffer gas produces intense light pulses. Excimer lasers are
available at power levels up to 300W and used mostly in the
fields of:
- micromachining (drilling,
etching, ablation, cutting)
- medical applications (eye
surgery, angioplasty, plastic surgery)
- semiconductor industry (wafer
production, flat panel displays)
The corrosive and toxic nature of halogens sets
stringent limitations on moisture content and requires
sophisticated gas supply equipment. This means specific
stainless steel regulators and panels, orbital welded
stainless steel piping, gas cabinets with exhaust lines,
halogen scrubber filters and gas detection systems with
alarms. |
