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Er:YAG (Erbium doped Yttrium Aluminium Garnet)
Er:YAG
is an excellent laser material for 2.94 μm laser emission. 2.94 μm is the most
readily absorbed into water and hydroxylapatite of all existing wavelengths, it
is also considered a highly surface cutting laser wavelength. The Er:YAG lasers
are widely applied in medical arear such as dental (hard tissues), orthopedics,
etc.
1.
Physical and Chemical Properties:
|
Crystal Structure |
Cubic |
|
Lattice Parameters (nm) |
1.201 |
|
Melting Point (K) |
2243 |
|
Moh
Hardness |
8.5 |
|
Density (g/cm3) |
4.56+/-0.04 |
|
Specific Heat (0-20) (J/g.cm3) |
0.59 |
|
Modulus of Elasticity (GPa) |
310 |
|
Young's Modulus (Kg/mm2) |
3.17*104 |
|
Poisson Ratio (est.) |
0.3 |
|
Tensile Strength (GPa) |
0.13~0.26 |
|
Thermal Expansion Coefficient
(/K) (0~250℃) |
[100]Direction:8.2*10-6 |
|
[110]Direction:7.7*10-6 |
|
[111]Direction:7.8*10-6 |
|
Thermal Conductivity (W/m/K) |
14@20oC |
|
10.5@100oC |
|
CThermal Optical Coefficient (dn/dT) (/K) |
7.3*10-6 |
|
Thermal Shock Resistance (W/m) |
790 |
|
Solubility |
Water:Insoluble; Common Acids: Slightly |
2. Optical and
lasing Properties of Er:YAG
|
Laser Transition |
4I11/2 to 4I13/2 |
|
Laser Wavelength (nm) |
2940
|
|
Photon Energy (J) |
6.75*10-20@2940nm |
|
Emission Cross Section (cm2) |
3*10-20 |
|
Index of Refraction |
1.79
@2940nm |
|
Pump
Bands (nm) |
600~800 |
3. Advantages of
Er:YAG Crystals
* High slope efficiency
* Room temperature operation
* Relatively eye-safe wavelength
4.
Standard Products specification
|
Er
Dopant concentration (at%) |
~50
|
|
Orientation |
[111] within 5o
|
|
Wavefront Distortion |
≤0.125λ/inch(@1064nm) |
|
Extinction Ratio |
≥25
dB |
|
Rod
Sizes |
Diameter:3～6mm,
Length:50～120
mm
Upon request of customer |
|
Dimensional Tolerances |
Diameter:+
0.000"/-0.002",
Length: +/-0.02" |
|
Barrel Finish |
Ground Finish: 400# Grit |
|
Parallelism |
≤10"
|
|
Perpendicularity |
≤5'
|
|
Flatness |
λ/10
|
|
Surface Quality |
10-5(MIL-O-13830A) |
|
Chamfer |
0.006"+/-0.002" at 45o+/-
5o
|
|
AR
Coating Reflectivity |
≤
0.25% (@2940nm) |
5.
Typical size Of Er.:YAG laser crystal
Ø
4 mm x 70 mm,50 at %Er flat/convex, HR 2940 nm/PR 2940 nm
Ø 4 mm x 90 mm, 50 at %Er flat/flat, AR 2940 nm
Ø 4 mm x 65 mm, 50 at %Er flat/flat, barrel polished,AR 2940 nm
Ø 4 mm x 80 mm, 50 at %Er flat/flat, barrel polished,AR 2940
nm
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