| L
A S E R •
Light Amplification by Stimulated Emission
of Radiation. An intense coherent beam of light radiant
energy stimulated by the amplification of high-energy atoms
from a laze medium, e.g., CO2 gas, nd:YAG, and
other engineered crystals and gases. Power Supply Stimulation
of the laze medium is accomplished by electromagnetic energy,
or from fiber optic transmission of diode light energy.
Direct diode semiconductor laser is a new technology that
provides unique material processing capabilities for industrial
manufacturers.
LASER
WAVE LENGTH •
The Wave-length absorption spectra of the material or part
is a Primary Factor for laser material processing
- CO2
@ 9.2 - 10.64 m
- IR
(nd:YAG) @ 808-1064 nm
|
- Green
@ 532 nm,
- UV
@ 266 - 355 nm.
|
Shorter
wavelength UV lasers offer two primary advantages in materials
processing applications:
- Materials
are processed by a relatively cold ablation "atomization"
process - high energy photons break atomic/molecular bonds
to remove material, versus a localized intense heating
and boiling process of longer wave length lasers.
- Shorter
wavelength lasers can be focused to smaller spot sizes
which, when configured with advanced Q-switched designs,
can be tuned to provide short pulse width (as short as
6 - 8 ns), and high repetition rates (up to 200 kHz) to
maximize materials absorption, maximizing processing speed
for increased production.
M2
is a laser beam profile rating •
Most laser material processes depend on energy density,
measured in Joules/cm2. Laser beam energy profiles can affect
processes differently. A beam profile analysis includes;
spot size, beam divergence, power, and energy propagation
properties of a laser beam. A collimated intrinsic stigmatic
beam with all propagation properties identical in x and
y transverse directions is theoretically ideal.
Reduced
Laser Beam Spot Size increases power density by the square
(X2) of laser power.
IRRADIANCE
•
Power Density of a Continuous Wave Laser from Emission of
rays of light.
FLUENCE
•
Specific Energy Density of a Pulsed Laser •
Peak pulse power can be 100 times or more than a lasers
power rating. High Repetition Rate (kHz) generally improves
laser-processing speeds. Pulse width stability is vital
to many material-processing parameters. |
