Nd:YAG
Nd:YAG
was invented in the 1960s, it has been and still is the most commonly
used solid-state crystal material. It can be used in lasers utilizing
frequency doubling and frequency tripling, and high-energy Q-switching.
Its thermal conductivity is higher and its fluorescence lifetime is about
twice as long than Nd:YVO4. It can be operated on power levels of up to
kilowatts. It can be directly Q-switched with Cr4+:YAG.
Physical and Optical Properties:
Chemical Formula Nd:Y3A15O12
Crystal Structure Cubic
Lattice Constants 12.01Ä
Concentration ~ 1.2 x 1020 cm-3
Melting Point 1970 deg.C
Density 4.56 g/cm3
Mohs Hardness 8.5
Refractive Index 1.82
Thermal Expansion Coefficient 7.8 x 10-6 /K [111], 0 - 250 deg.C
Thermal Conductivity 14 W/m /K @20 deg.C, 10.5 W /m /K @100 deg.C.
Optical Properties:
Lasing Wavelength: 1064 nm
Stimulated Emission Cross Section: 2.8x10-19
cm-2
Relaxation Time of Terminal Lasing Level: 30 ns
Radiative Lifetime: 550 ms
Spontaneous Fluorescence: 230 ms
Loss Coefficient: 0.003 cm-1 @ 1064 nm
Effective Emission Cross Section: 2.8 x 10-19 cm2
Pump Wavelength: 807.5 nm
Absorption band at pump wavelength: 1 nm
Linewidth: 0.6 nm
Polarized Emission: Unpolarized
Thermal Birefringence: High
General Specification:
1) Nd dopant concentration: 0.7 ~ 1.3 atm%Dopant tolerance: within 10% of concentration.
2) Diameter: 3 ~ 14mm
3) Length: 1 ~ 160mm
4) Anti-reflection Coating: R<0.1 @ 1064nm
High transmission Coating: T>95% @ 808nm
High reflection Coating: R>99.8% @ 1064nm
1) Orientation: <111> crystalline direction (+/-0.5deg.)
2) Wavefront Distortion:
<Lambda/10 per inch at 632.8nm for 3 ~7mm
>Lambda/10 per inch at 632.8nm for >=7mm
3) Surface quality: better than 20/10 Scratch/Dig per MIL-O-1380A
4) Parallelism: < 10 arc seconds
5) Perpendicularity: < 5 arc minutes
6) Surface flatness: <Λ/10 at 632.8nm
7) Clear aperture: Central 95%
8) Chamfer: 0.15x45deg.
9) Damage threshold: over 15J/cm2 (without coating), over 700 MW/cm2 (coating)
Diffusion Bonded of Nd:YAG/YAG, Nd:YAG/Cr4+:YAG crystals are available in OptoCity. These Diffusion Bonded Crystals are combined by optical contact method and further bonded under high temperature. Diffusion Bonded Crystal helps to decrease thermal lensing effect considerably.
