Description of Holmium-doped Yttrium Lithium Fluoride
Common lasing mediums for lasers are crystals, such as YAG, YLF, sapphire, etc., doped with a rare earth element like neodymium, erbium, or holmium.
Holmium-doped Yttrium Lithium Fluoride (Ho: YLF), emitting at 2.06 micrometers, is a promising material for laser target designators. Optical pumping of Holmium: Yttrium Lithium Fluoride (Ho: YLF) crystal with a 790-nm continuous-wave diode-laser array can generate 56 mW of 2.1 μm laser radiation with an optical-to-optical conversion slope efficiency of 33% while the crystal temperature is held at 77 K.
Synonym: Holmium yttrium lithium fluoride, Lithium holmium yttrium fluoride
Pattern Wavelengths of Neodymium, Erbium, Holmium or Thulium doped Lithium Yttrium Fluorides:
| Nd: YLF |
1.047 µm, 1.053 µm, 1.313 µm, 1.324 µm, and 1.370 µm |
| Er: YLF |
0.85 µm and 2.81 µm |
| Ho: YLF |
0.75 µm and 2.06 µm |
| Tm: YLF |
0.435 µm, 1.89 µm, and 2.30 µm |
Specification of Holmium-doped Yttrium Lithium Fluoride
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%
|
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
|
Applications of Holmium-doped Yttrium Lithium Fluoride
1. Medical Applications: Ho:YLF lasers are commonly used in medical procedures such as ophthalmology, urology, and surgery. They are effective for precise tissue cutting, ablation, and lithotripsy (breaking down kidney stones) due to their specific wavelength absorption in water and biological tissues.
2. Scientific Research: Ho:YLF lasers are utilized in spectroscopy and other scientific studies requiring mid-infrared wavelengths. Their tunability and narrow linewidths make them ideal for precise measurements and experiments in physics and chemistry.
3. Industrial Uses: These lasers are used for materials processing tasks such as cutting, drilling, and marking, particularly for materials that require high precision and minimal thermal damage. Ho:YLF lasers' specific wavelength characteristics make them suitable for processing certain types of plastics and composites.
4. Military and Defense: Ho:YLF lasers are employed in rangefinding, target designation, and other applications where precise distance measurements and targeting are crucial. Their ability to operate efficiently at eye-safe wavelengths is an added advantage in these fields.
5. Remote Sensing and Environmental Monitoring: Ho:YLF lasers are used in LIDAR systems for atmospheric measurements, pollution monitoring, and topographical mapping. Their specific wavelengths are useful for detecting various atmospheric constituents and providing accurate environmental data.
Packing of Holmium-doped Yttrium Lithium Fluoride
Our Holmium-doped Yttrium Lithium Fluoride is clearly tagged and labeled externally to ensure efficient identification and quality control. Great care is taken to avoid any damage which might be caused during storage or transportation.
Specification
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%
|
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
|
