Descriptions:
HGO grows Ho:YLF crystal Holmium-doped Yttrium Lithium
Fluoride . Ho:YLF is a very attractive laser
material, because the lifetime of the upper laser level is much longer ( ~ 14
ms) than in Ho:YAG and the emission cross sections are higher. Additionally the
thermal lens in Ho:YLF is much weaker, which helps to generate diffraction
limited beams even under intense end-pumping.
Optical and
physical properties of Ho:YLF crystal
|
Absorption peak wavelength
|
1940nm
|
|
Absorption cross-section at peak
|
1,2×10-20 cm2
|
|
Absorption bandwidth at peak wavelength
|
~18 nm
|
|
Laser wavelength
|
2060 nm
|
|
Lifetime of 5I7 energy level
|
10 ms
|
|
Emission cross-section
|
1,8×10-20 cm2
|
|
Refractive index @1064 nm
|
no=1,448, ne=1,470
|
|
dn/dT
|
-4,6 × 10-6 (||c) K-1, -6,6 × 10-6 (||a) K-1
|
|
Thermal expansion coefficient
|
10,1 × 10-6 (||c) K-1, 14,3 × 10-6 (||a) K-1
|
|
Thermal Conductivity /(W·m-1·K-1)
|
6 Wm-1K-1
|
|
Crystal structure
|
tetragonal
|
|
Melting Point
|
819°C
|
|
Density
|
3.95 g/cm3
|
|
Mohs hardness
|
5
|
|
Typical doping level
|
0.5-1%
|
HGO offers
Pr:YLF specifications:
|
Doping(atm%):
|
0.5% ~ 1%
|
|
Orientation:
|
a-cut/c-cut crystalline direction
|
|
Wavefront Distortion:
|
λ/4per inch @ 632.8 nm
|
|
Dimension Tolerances：
|
+0.0/-0.05 mm , Length: ±0.1 mm
|
|
Surface Quality:
|
10/5 Scratch/Dig MIL-O-1380A
|
|
Parallelism:
|
< 10″
|
|
Perpendicularity:
|
< 5′
|
|
Clear Aperture:
|
> 90%
|
|
Surface Flatness:
|
< λ/10 @ 632.8 nm
|
|
Chamfer:
|
< 0.1 mm @ 45o
|
|
Barrel Finish
|
50-80 micro-inch (RMS) ,
|
|
Size
|
Upon customer request
|
|
Coating
|
AR/HR/PR coating upon customer’s request
|
|
Damage Threshold
|
750MW/CM2 at 1064nm, TEM00, 10ns, 10Hz
|
|
Quality Warranty Period
|
One
year under proper use
|
Other YLF-based Nd/Pr/Tm/Yb/Er/Ce YLF are
also available upon request.
Advantages:
1)
Long upper laser level lifetime ~ 15 ms
2)
Higher
emission cross-section
3)
Low dn/dT
–> weak thermal lensing
4)
Highest (to the best of our knowledge) CW output of
21 W for 2-μm Ho:YLF laser
5)
Efficient Q-switched operation (up to 37 mJ per
pulse)
Why
Choose HGO ?
HG
OPTRONICS.,INC. grow YLF-based crystals in house using CZ growth
technology. The use of high quality starting materials for crystal growth,
whole boule interferometry, precise inspection of scattering particle in
crystal using He-Ne laser and delicated measurement of bulk losses using
spectrophotometer assures that each crystal will comply with customer’s specification and perform well.
And base on our diffusion bonding
technology various YLF-based configurations are availabl to supply,
