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Active
elements from Erbium doped Yttrium Scandium Gallium Garnet crystals
(Er:Y3Sc2Ga3012
or Er:YSGG), single crystals, are desinged for diode pumped solid-state
lasers radiating in the 3 µm range. Er:YSGG crystals show the perspectiveness
of their application alongside with the widely used Er:YAG, Er:GGG and
Er:YLF crystals.
Flash lamp pumped solid-state lasers based on Cr,Nd and Cr,Er doped Yttrium
Scandium Gallium Garnet crystals (Cr,Nd:Y3Sc2Ga3012
or Cr,Nd:YSGG and Cr,Er:Y3Sc2Ga3012
or Cr,Er:YSGG) have a higher efficiency than those based on Nd:YAG and
Er:YAG. Active elements manufactured from YSGG crystals are optimum
for medium power pulse lasers with the repetition rates of up to several
tens of cycles. The advantages of YSGG crystals compared with YAG crystals
are lost when large size elements are used because of the worse thermal
characteristics of YSGG crystals. |
PROPERTIES:
| Crystal |
Er3+:YSGG |
Cr3+,Nd3+:YSGG |
Cr3+,Er3+:YSGG |
| Crystal
structure |
cubic |
cubic |
cubic |
| Dopant
concentration |
30 - 50
at.% |
Cr: (1
÷ 2) x 1020; Nd: (2 ÷ 3) x 1020 |
Cr: (1
÷ 2) x 1020; Er: 4 x 1021 |
| Spatial
group |
Oh10 |
Oh10 |
Oh10 |
| Lattice
constant, Å |
12.42 |
12.42 |
12.42 |
| Density,
g/cm3 |
5.2 |
5.2 |
5.2 |
| Orientation |
<001>,
<111> |
<001>,
<111> |
<001>,
<111> |
| Mohs hardness |
>7 |
> 7 |
> 7 |
| Thermal
expansion coefficient |
8.1 x
10-6x°K-1 |
8.1 x
10-6 x°K-1 |
8.1 x
10-6 x°K-1 |
| Thermal
conductivity, W x cm-1 x °K-1 |
0.079 |
0.06 |
0.06 |
| Refractive
index, at 1.064 µm |
1.926 |
- |
- |
| Lifetime,
µs |
- |
240 |
1400 |
| Emission
cross-section, cm2 |
- |
1.5 x
10-19 |
5.2 x
10-21 |
| Relative
(to YAG) efficiency of transformation of energy of the flash
lamp |
- |
2.3 |
1.5 |
| Termooptical
factor (dn/dT) |
7 x 10-6
x°K-1 |
- |
- |
| Generated
wavelength, µm |
2.797;
2.823 |
- |
- |
Comparative
generation characteristics:
| Crystal
type |
Er:YSGG |
Er:YAG
|
| Er
concerntation, at. % |
38 |
33 |
| Pumping
wavelength, nm |
966 |
964 |
| Stimulated
radiation wavelength, µm |
2.797;
2.823 |
2.830 |
| Generation
threshold, mW |
72 |
418 |
| Max.
power output at pumping power 720 mW, 966 nm |
201 |
51 |
| Slope
efficiency, % |
31.1 |
16.9 |
Characteristics
and applications of YSGG:
| Dopant |
Cr,Nd |
Cr,Ho,Tm |
Cr,Er |
| Lasing
wavelength, µm |
1.058 |
2.088 |
2.791 |
| Refractive
index |
1.9263 |
1.9263 |
1.9263 |
| Termooptical
factor (dn/dT) |
12.3
x 10-6 x °K-1 |
12.3
x 10-6 x °K-1 |
12.3
x 10-6 x °K-1 |
Ultimate
lasing regimes,
Free running mode |
overall
efficiency 8% |
overall
efficiency 2.1%
slope efficiency 3.1% |
overall
efficiency 2.1%
slope efficiency 3.0% |
Ultimate
lasing regimes,
Electro-optical Q-switch |
pulse
energy 500 mJ
overall efficiency 4% |
-
|
overall
efficiency 0.16%
slope efficiency 0.38% |
| Sizes,
(dia x length), mm |
from
3 x 30 to 12.7 x 152.4 |
from
3 x 30 to 9.5 x 101.6 |
from
3 x 30 to12.7 x 127.0 |
| Fields
of applications |
material
processing, scientific investigations |
material
processing, medical applications, lithotripsy |
material
processing, medical applications, scientific investigations |
Rods with
round cross-sections are manufactured:
| Diameter
tolerance, mm |
+
0.0 / -0.1 |
| Length
tolerance, mm |
+1.0 /
-0.0 |
| Chamfer |
45 ±
10° x 0.2 ± 0.1 mm |
| Parallelism |
< 30' |
| Perpendicularity |
< 15' |
| Flatness |
< 0.2 |
| Absorption
loss at 1150 nm, cm-1 |
< 0.005 |
We supply rods and
slabs with different cross-sections, dimensions and coatings. Different
dopants compositions with different concentrations are available for
specific customer requirements.
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