Nd:YAG (Neodymium-Doped Yttrium Aluminum Garnet) Single Crystal

Advantages

• Most widely used solid-state laser material: Nd:YAG is the first and most famous laser crystal, serving as the foundational component for near-infrared solid-state lasers and their frequency multipliers.
• Excellent thermal and mechanical properties: High thermal conductivity (~13–14 W/(m·K)), Mohs hardness of 8.5, and high thermal shock resistance enable reliable high-power operation.
• Low lasing threshold and high gain: Relatively narrow gain bandwidth (~0.6 nm) allows high gain efficiency and low threshold operation.
• Good spectral matching with laser diodes: Wide absorption band near 808 nm coincides with the emission of AlGaAs laser diodes, enabling efficient diode pumping.
• High optical quality and large-diameter growth: Czochralski method enables production of large, core-free crystals with excellent optical homogeneity.
• Isotropic crystal structure: Cubic symmetry eliminates polarization-dependent effects and stress-induced birefringence concerns.

Typical Specifications

• Chemical formula: Nd:Y₃Al₅O₁₂
• Crystal structure: Cubic garnet, space group Ia3d
• Lattice constant: a = 12.01 Å
• Nd doping concentration: 0.1–1.2 at.%
• Laser wavelength: 1064 nm (primary); also 946 nm, 1120 nm, 1320 nm, 1440 nm
• Pump wavelength: 808 nm
• Absorption bandwidth: ~2.5 nm at 808 nm peak
• Emission cross-section: 3–6.5 × 10⁻¹⁹ cm² @ 1064 nm
• Fluorescence lifetime: ~230–250 μs (1% Nd)
• Refractive index: 1.82 @ 1064 nm
• Density: 4.56 g/cm³
• Melting point: 1950–1970 °C
• Mohs hardness: 8.5
• Thermal conductivity: ~13–14 W/(m·K) @ 25 °C
• Thermal expansion coefficient: 7.7–8.2 × 10⁻⁶/K (orientation-dependent)
• Loss coefficient: 0.003 cm⁻¹ @ 1064 nm
• Laser damage threshold: >750 MW/cm² @ 1064 nm, 10 ns; >10 J/cm² @ 1064 nm, 10 ns (AR-coated)

Standard Fabrication Specifications:

• Orientation: [111], [110], or [100] ± 0.5°
• Diameter: 2–15 mm (standard); lengths up to 180 mm
• Surface quality: 10/5 Scratch/Dig
• Surface flatness: λ/8 @ 632.8 nm
• Wavefront distortion: λ/10 @ 632 nm per inch
• Parallelism: <10–20 arc sec
• Perpendicularity: <5–15 arc min
• Clear aperture: >90–95%
• Chamfer: <0.2 mm × 45°
• AR coating: R < 0.15–0.2% @ 1064 nm

Main Applications

• High-power material processing: Nd:YAG lasers are extensively used for welding, drilling, cutting, trimming, and marking of metals, ceramics, and polymers.
• Frequency-converted lasers: Second (532 nm), third (355 nm), and fourth (266 nm) harmonic generation for precision micromachining, lithography, and scientific research.
• Medical laser systems: Used in surgical procedures, ophthalmology, dermatology, and therapeutic applications.
• LIDAR and ranging: Q-switched Nd:YAG lasers provide high-peak-power pulses for remote sensing, laser rangefinders, and target designation.
• Scientific research: Pump source for optical parametric oscillators (OPOs), Ti:sapphire amplifiers, and ultrafast laser systems.
• Military and aerospace: Directed energy systems, countermeasures, and range finding applications.
• Biophysics and analytical chemistry: Laser ablation ICP-MS, fluorescence spectroscopy, and photostimulation therapies.