Description of Thulium-Doped Yttrium Aluminum Garnet Crystal
Tm: YAG operating on the 3H4 -3H6 transition in the 0.82 µm wavelength range. It can be pumped with efficient diode lasers in the 0.78 - 0.8 mm wavelength range. The transition has a small quantum defect for low thermal dissipation. The upper state lifetimes can be long, on the order of a millisecond for good energy storage. It also has sufficient gain bandwidth to support sub-ps-long pulses depending on the host material and temperature of operation. Compared with the single-crystal material, the transparent ceramic materials combine the advantages of single crystals and glasses. The transparent ceramic materials are fabricated by solid-state reaction and vacuum sintering. So, they not only possess good optical and thermal properties as fine as single crystals but also can be fabricated with large size, high concentration. Furthermore, they also have other superiorities, such as a short fabrication period and less cost.
Advantages of Tm: YAG:
- High quantum efficiency
- High efficiency with LD pump
- Long upper state lifetime
- Sufficient gain bandwidth
- Small quantum defect
- High damage threshold
Specifications of Thulium-Doped Yttrium Aluminum Garnet Crystal
Material specifications
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Tm concentration tolerance
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Tm: 0.5~5 at%
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Orientation
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[111], <5°
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Parallelism
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≤10"
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Surface quality
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10-5(MIL-0-13830A)
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Perpendicularity
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<5'
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Wavefront distortion
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≤ 0.125λ/25 mm @632.8nm
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Surface flatness
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λ/8@632nm
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Clear aperture
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>95%
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Chamfer
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0.15±0.05mm
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Size
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D: 2~10mm, L: 3~150mm
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Coatings
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AR: ≤0.25% @2µm
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Optical and spectral properties
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Laser transition
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3 F4 →3 H6
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Laser wavelength
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1.87~2.16µm
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Temperature dependence of the refractive index
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7.3 10-6/K
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Absorption cross-section
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7.5×10-21cm2
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diode pump band
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785nm, 680nm
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Emission cross section@2013nm
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2.9×10-20 cm2
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Fluorescence lifetime
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11ms
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Refractive index@632nm
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1.83
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Applications of Thulium-Doped Yttrium Aluminum Garnet Crystal
- 2000m laser
- Medical laser
- Laser radar
- Atmospheric sensing
- Military engineering
- Photoelectric countermeasures
- Remote sensing