KTP (potassium titanyl phosphate) is a nonlinear crystal that is widely used in laser technology for frequency conversion. KTP has a relatively high nonlinear coefficient, a wide transparency range, and good thermal and mechanical properties, making it suitable for a range of applications such as second harmonic generation (SHG), optical parametric amplification (OPA), and difference frequency generation (DFG).
In SHG, the frequency of a laser beam is doubled by passing it through a KTP crystal. This process is used to generate light in the ultraviolet range, which is useful in applications such as fluorescence microscopy and laser spectroscopy.
OPA is a process that involves the generation of two coherent light beams with different frequencies. KTP can be used as the nonlinear crystal in an OPA to generate tunable mid-infrared radiation, which has applications in remote sensing, environmental monitoring, and medical diagnostics.
DFG produces a new frequency that is equal to the difference between two input frequencies. KTP can be used in DFG to generate tunable mid-infrared radiation, which has applications in spectroscopy, sensing, and imaging.
KTP has a relatively high damage threshold, which makes it suitable for high-power laser applications. It also has good thermal stability, which means its optical properties are less sensitive to temperature changes. Additionally, KTP has a relatively low absorption coefficient, which means it can be used with high power lasers without significant degradation in performance.
However, KTP is a relatively expensive material compared to other nonlinear crystals, which can limit its use in certain applications. Additionally, KTP crystals can be difficult to grow and fabricate, which can increase their cost and lead times.
|Transparency range, nm||350 - 4500|
|Crystal structure, Point group||orthorhombic, point group mm2|
|Lattice parameters, Å||a = 12.818, b = 6.404, c = 10.596 Å|
|Thermal expansion coefficient, at 100 °C:||±1 = 8.7 x 10-6 x °C-1|
|±2 = 10.5 x 10-6 x °C-1|
|±3 = -0.2 x 10-6 x °C-1|
|Thermal conductivity, mW x cm -1 x °C -1||k1 = 20, k2 = 30, k3 = 33|
|Non-linear coefficient, pm/V||d31 = 6.5; d32 = 5.0; d33 = 13.7; d34 = 7.6; d35 = 6.1;|
|Electrooptic coefficients||r13 = 9.5, r23 = 15.7, r33 = 36.3 pm/V|
|at 1064 nm||nx = 1.738; ny = 1.746; nz = 1.830|
|at 532 nm||nx = 1.779; ny = 1.789; nz = 1.889|
|Optical damage threshold, MW/cm2||500 (1064 nm, 20 ns, 20 Hz)|
|Conversion efficiency, %||60 (1064 nm, 10 ns, 50 Hz, 2 W)|