Potassium Titanyl Phosphate (KTiOPO₄), commonly known as KTP, is one of the most widely used nonlinear optical crystals for solid-state laser systems. It is especially valued for its high nonlinear optical coefficients, wide angular acceptance, broad temperature and spectral bandwidths, and excellent frequency-doubling efficiency.
KTP is a preferred material for second harmonic generation (SHG) of Nd:YAG and Nd:YVO₄ lasers, as well as for optical parametric oscillators (OPOs) and other nonlinear frequency conversion applications. Its mechanical robustness and stable optical performance make it suitable for both commercial and demanding military or industrial laser systems.
Physical & Mechanical Properties
| Parameter | Value |
|---|---|
| Density | 3.01 g·cm⁻³ |
| Melting Point | 1172 °C |
| Mohs Hardness | 5 |
| Thermal Conductivity | 13 W·m⁻¹·K⁻¹ |
| Thermal Expansion | aₓ = 11 × 10⁻⁶ °C⁻¹ aᵧ = 9 × 10⁻⁶ °C⁻¹ a_z = 0.6 × 10⁻⁶ °C⁻¹ |
| Crystal Structure | Orthorhombic System |
| Lattice Constants | a = 6.404 Å, b = 10.616 Å, c = 12.814 Å |
Optical & Nonlinear Properties
| Parameter | Value |
|---|---|
| Transparency Range | 350 – 4500 nm |
| SHG Phase-Matchable Range | 497 – 1800 nm (Type II) |
| Thermal-Optic Coefficients | dnₓ/dT = 1.1 × 10⁻⁵ °C⁻¹ dnᵧ/dT = 1.3 × 10⁻⁵ °C⁻¹ dn_z/dT = 1.6 × 10⁻⁵ °C⁻¹ |
| Absorption Coefficient | < 0.1% @1064 nm < 1% @532 nm |
| Non-Vanishing NLO Coefficients | d₃₁ = 6.5 pm·V⁻¹ d₃₂ = 5.0 pm·V⁻¹ d₃₃ = 13.7 pm·V⁻¹ d₂₄ = 7.6 pm·V⁻¹ d₁₅ = 6.1 pm·V⁻¹ |
Effective Nonlinear Coefficient (Type II)
deff(II)=(d24−d15)sin2ϕsinθ−(d15sin2ϕ+d24cosϕ)sinθ
Standard Manufacturing Specifications
| Item | Specification |
|---|---|
| Dimension Tolerance | W × H ±0.1 mm, L +0.5 / −0.1 mm |
| Angular Tolerance | Δθ ≤ 0.25°, Δφ ≤ 0.25° |
| Parallelism | < 20 arc sec |
| Perpendicularity | < 5 arc min |
| Chamfer | 0.1 mm × 45° |
| Clear Aperture | ≥ 90% |
| Scratch & Dig | 10/5 |
| Surface Flatness | λ/8 @ 633 nm |
| Wavefront Distortion | λ/8 @ 633 nm |
| Damage Threshold (AR-coated) | >0.5 GW·cm⁻² (@1064 nm, TEM₀₀, 10 ns, 10 Hz) >0.3 GW·cm⁻² (@532 nm, TEM₀₀, 10 ns, 10 Hz) |
Key Advantages
- High nonlinear optical coefficient for efficient SHG
- Wide angular acceptance and small walk-off angle
- Broad temperature and spectral bandwidths
- High laser damage threshold for pulsed laser systems
- Wide transparency range from visible to mid-IR
- Excellent stability and reliability in long-term operation
Typical Applications
- Green Laser Generation: Frequency doubling of 1064 nm lasers to 532 nm
- Laser Range Finders & LIDAR: Compact, efficient wavelength conversion
- Medical Laser Systems: Dermatology, surgery, and precision treatments
- Optical Parametric Oscillators (OPOs): Tunable wavelength generation
- Industrial & Military Lasers: Materials processing, targeting, and optical communication systems
Shape Optics Capabilities
Shape Optics supplies high-quality KTP crystals for research, industrial, and OEM laser applications.
Available Configurations
- Rod diameter: 1 – 40 mm
- Length: 1 – 60 mm
- Crystal cut & orientation: custom on request
- Optical coatings: AR and custom coatings available
With over 20 years of experience in optical manufacturing, Shape Optics combines precision crystal processing, advanced polishing, and in-house coating capabilities across the UV–NIR spectrum. Our solutions emphasize performance consistency, fast delivery, and full compliance with international optical standards.
For reliable nonlinear optical solutions, contact Shape Optics to discuss your KTP crystal requirements.