YVO₄ (Yttrium Orthovanadate) Single Crystal

Advantages

• Large birefringence: Δn = 0.2225 at 0.63 μm and 0.2039 at 1.55 μm, significantly higher than calcite and rutile, making YVO₄ ideal for polarization-control components in fiber-optic isolators, circulators, and beam displacers.
• Broad transparency range: High transmittance from 0.4 to 5 μm, covering visible to mid-infrared applications.
• Excellent synthetic substitute for natural crystals: Higher hardness, better fabrication properties, and water insolubility compared with calcite; easier to grow large, high-quality crystals at lower cost than rutile.
• Superior laser host properties (when doped with Nd³⁺): Large stimulated emission cross-section at 1064 nm (approximately 4 times that of Nd:YAG), strong broad absorption band around 808 nm (about 4 times higher absorption coefficient than Nd:YAG), and inherent linearly polarized output along the π-direction.
• Non-hygroscopic and chemically stable: Suitable for long-term device integration without protective coatings in many applications.

Typical Specifications

• Chemical formula: YVO₄
• Crystal structure: Zircon-type tetragonal, space group D₄ₕ (I4₁/amd)
• Lattice parameters: a = b = 7.12 Å, c = 6.29 Å
• Transparency range: 400–5000 nm
• Refractive indices:
  • at 0.63 μm: nₒ = 1.9929, nₑ = 2.2154, Δn = 0.2225, ρ = 6.04°
  • at 1.06 μm: nₒ = 1.95714, nₑ = 2.16498
  • at 1.30 μm: nₒ = 1.9500, nₑ = 2.1554, Δn = 0.2054, ρ = 5.72°
  • at 1.55 μm: nₒ = 1.9447, nₑ = 2.1486, Δn = 0.2039, ρ = 5.69°
• Density: 4.22 g/cm³
• Mohs hardness: 5 (glass-like)
• Thermal expansion coefficients: αₐ = 4.4 × 10⁻⁶/K, αc = 11.4 × 10⁻⁶/K
• Thermal conductivity: 5.23 W/(m·K) parallel to c-axis; 5.10 W/(m·K) perpendicular to c-axis
• Thermal optical coefficients: dnₒ/dT = 8.5 × 10⁻⁶/K, dnₑ/dT = 3.0 × 10⁻⁶/K

Sellmeier equations (λ in μm) :

nₒ² = 3.77834 + 0.069736/(λ² − 0.04724) − 0.0108133λ²

nₑ² = 4.59905 + 0.110534/(λ² − 0.04813) − 0.0122676λ²

Main Applications

• Fiber-optic isolators and circulators: Undoped YVO₄ is a key material for polarization-management components in optical communication systems, enabling compact and reliable device designs.
• Beam displacers and polarizing optics: Used in polarization beam splitters, Glan polarizers, and beam-displacement prisms, offering superior performance over calcite in many visible and near-IR applications.
• Nd:YVO₄ laser gain medium: The most important application of YVO₄ crystals. Nd:YVO₄ is one of the most outstanding laser crystals for diode-pumped solid-state lasers, widely used in industrial, medical, and scientific systems.
• High-repetition-rate Q-switched lasers: Nd:YVO₄ is particularly suitable for passively Q-switched operation at high repetition rates (kHz to MHz), achieving pulse durations of 1–70 ns and peak powers in the kW range.