Potassium titanyl phosphate (KTiOPO4, KTP) is an excellent nonlinear optical material with large nonlinear optical coefficients, wide angular bandwidth, and small departure angles, among other excellent nonlinear and electro-optical properties.
KTP crystals are used in a variety of commercial and military lasers, including laboratory and medical systems, rangefinders, lidar, optical communications, and industrial laser systems. Alfa Chemistry is an expert in creating nonlinear crystals to order and will carefully and patiently walk customers through the online customization procedure for KTP nonlinear crystals.
Advantages of KTP Crystals
KTP crystal has many superior properties, including a high nonlinear optical coefficient (roughly 15 times that of KDP crystal), high electro-optic (EO) coefficient, low dielectric constant, high thermal conductivity (2 times that of BNN crystal), wide angular bandwidth and small walk-off angle, wide temperature and spectral bandwidth, and many others. KTP crystals also exhibit good chemical and mechanical characteristics and are not hygroscopic. The optical surface is extremely polished, the mismatch gradient is the shortest, and it doesn't decompose below 900 ℃.
Fig 1. Structure of KTP single crystals. (Novikova N. E, et al. 2018)
Properties of KTP Crystals
| Physical Properties | |
|---|---|
| Crystal Structure | Orthorhombic, space group Pna21 |
| Lattice Parameter | a=6.404Å, b=10.616Å, c=12.814A, Z=8 |
| Density | 3.01 g/cm3 |
| Melting Point | ~ 1172 ℃ |
| Mohs Hardness | 5 |
| Thermal Conductivity | 13 W/m/K |
| Thermal Expansion Coefficients | ax=11x10-6/℃, ay=9x10-6/℃, az=0.6x10-6/℃ |
| Refractive Indices | nX = 1.7404; nY = 1.7479; nZ = 1.8296 @1064 nm |
| Optical and Nonlinear Properties | |
| Transparency Range | 350 ~ 4500 nm |
| Absorption Coefficients | <0.1%/cm at 1064 nm; <1%/cm at 532 nm |
| Therm-optic Coefficient | dnx/dT=1.1X10-5/℃; dny/dT=1.3X10-5/℃; dnz/dT=1.6X10-5/℃ |
| NLO Coefficients | deff(II)≈(d24 - d15)sin2Φsin2θ - (d15sin2Φ + d24cos2Φ)sinθ |
| Relative Dielectric Constant | εeff=13 |
| Sellmeier Equations | nx2=3.0065+0.03901/(λ2-0.04251)-0.01327λ2 ny2=3.0333+0.04154/(λ2-0.04547)-0.01408λ2 nz2=3.3134+0.05694/(λ2-0.05658)-0.01682λ2 |
Electro-optic Coefficients r13 r23 r33 r51 r42 | Low and High frequency 9.5 and 8.8 pm/V 15.7 and 13.8 pm/V 36.3 and 35 pm/V 7.3 and 6.9 pm/V 9.3 and 8.8 pm/V |
| Alfa Chemistry offers KTP specification | |
| Dimension | Upon customer request |
| Dimension Tolerance | Dimension+0/-0.1 mm, L±0.1mm |
| Cutting Angle Tolerance | △θ≤±0.25°,△φ≤±0.25° |
| Flatness | λ/10 @ 632.8nm |
| Surface Quality | 10/5 per MIL-O-13830A |
| Clear Aperture | > 90% |
| Damage Threshold | 750MW/cm2 at 1064nm, TEM00, 10ns, 10Hz |
| Coating | AR/HR coating upon customer's request |
| Quality Warranty Period | One year under proper use |
For in-cavity SHG configurations in low peak power CW lasers, our KTP crystals will be optimized. Our SHG efficiency mapping for each crystal will select special top quality materials, fine surface polishing and dual band AR coatings with very low loss, which allows us to produce KTP crystals for in-cavity SHG applications.
Why Choose Alfa Chemistry?
Customers may purchase top-notch nonlinear crystals of potassium titanyl phosphate from Alfa Chemistry. The size is customized to fit the needs of the customer. Additionally, we provide high-grey mark resistance HGTR-KTP crystals, which can considerably enhance performance and resistance to grey marks. High power applications can now use KTP as a nonlinear medium thanks to HGTR-KTP crystals. We also grew and studied KTP single crystals doped with Zr, Hf and Nb by spontaneous crystallization. An increase in SHG signal was observed at approximately 4-5% concentrations of these impurities.
If you need technical advice, please contact our technical team to learn more about our high-quality services.
Reference
- Novikova N. E, et al. (2018). "Structural Reasons for the Nonlinear Optical Properties of KTP Family Single Crystals." Crystals. 8(7): 283.