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Neodymium-doped yttrium aluminium garnet laser crystal (Nd:YAG)
provides the laser system designer with the most versatile solid state laser
source in use today. With thousands of systems in daily use, Nd:YAG continues
as the best of the rare earth garnet laser materials characterised by four level
laser operation; permitting low threshold pulse or CW operation. Nd:YAG laser
rods from Saint-Gobain Crystals & Detectors produce efficient laser output at
1.064 µm. The systems designer can select from several levels of dopant concentration
to optimise laser performance.
For
mobile applications, size and
weight of the laser systems are
important. The laser must be able
to produce Q- switched operation
and high brightness from a limited
input power. Rods with a high
dopant concentration, 1.0 to 1.2
atomic percent Nd, are normally
specified to achieve the best
pump efficiency.
On the factory floor and other industrial settings, where
input power is more available, Nd:YAG laser rods with dopant levels of 0.7 to
1.0 atomic percent Nd are very effective. Rods at this dopant level are an excellent
choice for pulse and multimode CW laser systems to provide high output power
coupled with balanced pumping uniformity and excellent beam quality.
When single mode (TEM00)
operation is required, the selection of the proper dopant concentration is critical
to the system's operation. Generally, the optimum laser rods for such systems
have Nd doping concentrations in the range of 0.5 to 0.8 atomic percent. The
final selection is based on many specific system design factors such as lamp
versus diode pumping, mode stability, polarisation, beam divergence, etc.
In any design
calculation or evaluation of the
Nd:YAG laser, the thermal loading
of the rod must be considered.
The objective is a careful balance
of output power requirements versus
the tolerance for thermal effects.
Years of experience in
Nd:YAG and other laser materials
enables us to offer useful assistance
with the material selection to
create a successful beam profile
and optimise the performance of
your laser.
| Laser Action | 4
Level Laser |
Output
Wavelength |
1.064 µm |
| Radiative Lifetime | (4F3/2
4I11/2)
550ms |
Emission
Cross Section |
Σ 21
= 2.7 -8.8 x 10-19
cm2 |
|
Spontaneous Fluorescence Lifetime |
230 µs |
Refractive
Index |
1.8
at 1.0 µm |
| Absorption bands | Flashlamp
Pumped |
Chemical
Formula |
Y3Al5O12:Nd
|
| Feature | Standard |
Special Order |
| Crystal Orientation | <111> within 5° |
Available |
| Diameter | 3
mm to 10mm |
Available |
| Diameter Tolerance | +0.0
mm/- 0.05 mm |
Available |
| Length (plano/plano) | 30
mm to 150 mm |
Available
|
| Length Tolerance | ± 0.75 mm |
± 0.50 mm |
| Perpendicularity of End Faces (plano/plano) | 5
arc-minutes |
2
arc-minutes |
| Parallelism of End Faces (plano/plano) | 10
arc-seconds |
|
| Flatness | 0.1
wave maximum |
0.10
wave maximum |
| (plano/plano) | over
90% of aperture |
over
full aperture |
| Surface Finish at 5X | 20-10
(scratch & dig) |
10-5
(scratch & dig) |
| Barrel Finish | 400
grit |
Polished
approx. 80-50 |
| End Face Bevel | 0.075
mm to 0.12 mm at 45° angle |
|
| Chips | No chips allowed on end face of rod; chip having maximum length of 0.3 mm permitted to lie in the area of bevel and barrel surfaces. | |
| End Configurations | plano/plano, plano/wedge, wedge/wedge or Brewster cut. Plano ends can be finished flat, concave or convex | |
| Coatings | Standard coating is AR at 1.064 µm with R < 0.25% each face. Other coatings available. |