Potassium Titanyl Arsenate (KTiOAsO₄), commonly known as KTA, is a high-performance nonlinear optical crystal particularly suited for optical parametric oscillation (OPO) and frequency conversion in the near- and mid-infrared regions. Compared with KTP, KTA offers significantly reduced absorption in the 2–5 μm region, broader angular and temperature bandwidths, and excellent performance under high laser power.
KTA is widely used in advanced laser systems where stable operation, wide tunability, and high damage resistance are required.
Physical & Mechanical Properties
| Parameter | Value |
|---|---|
| Density | 3.454 g·cm⁻³ |
| Melting Point | 1130 °C |
| Mohs Hardness | 5 |
| Thermal Conductivity | K₁ = 1.8, K₂ = 1.9, K₃ = 2.1 W·m⁻¹·K⁻¹ |
| Crystal Structure | Orthorhombic System |
| Lattice Constants | a = 13.125 Å, b = 6.5716 Å, c = 10.786 Å |
Optical & Nonlinear Properties
| Parameter | Value |
|---|---|
| Transparency Range | 350 – 5300 nm |
| Absorption Coefficient |
< 0.05% @1064 nm < 0.05% @1533 nm < 5% @3475 nm |
| SHG Phase-Matchable Range | 1083 – 3789 nm |
| Nonlinear Optical Susceptibilities |
d₃₁ = 2.76 pm·V⁻¹ d₃₂ = 4.74 pm·V⁻¹ d₃₃ = 18.5 pm·V⁻¹ d₁₅ = 2.3 pm·V⁻¹ |
Refractive Index (Sellmeier Coefficients)
Refractive indices are described using Sellmeier equations with coefficients (A, B, C, D) for Nx, Ny, and Nz, as provided in the specification data, enabling accurate phase-matching and optical design across the full transparency range.
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
- Excellent performance for OPO and OPA applications
- Low absorption in the 2–5 μm region, superior to KTP
- High nonlinear optical and electro-optic coefficients
- Broad angular and temperature acceptance bandwidths
- High laser damage threshold for high-power pulsed systems
- Wide transparency range extending into the mid-infrared
Typical Applications
- Optical Parametric Oscillators (OPOs): Tunable mid-IR laser sources (3–4 μm region)
- Optical Parametric Amplifiers (OPAs): High-energy amplification with broad wavelength coverage
- Frequency Conversion of Nd-Doped Lasers: Efficient operation at 1064 nm and longer wavelengths
- LIDAR & Remote Sensing: Infrared laser generation for environmental monitoring
- Spectroscopy & Medical Diagnostics: Mid-IR sources for molecular detection and imaging
Shape Optics Capabilities
Shape Optics supplies high-quality KTA crystals for research, industrial, and OEM laser systems.
Available Configurations
- Rod diameter: 1 – 30 mm
- Length: 1 – 30 mm
- Crystal orientation & cut: 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 consistency, performance, and compliance with international optical standards.
For reliable nonlinear optical solutions in the mid-infrared, contact Shape Optics to discuss your KTA crystal requirements.