KNbO₃ ( Potassium Niobate)

1.     Applications:

KnbO₃ crystal is an uniquely superior ferroelectric crystal characterized

by:

* Highest nonlinear optical figure of merit

* Highest electro-optical figure of merit

* Highest photorefractive figure of merit

* High chemical stability.

* Strong beam coupling effect (Fe:KN)

It is mainly used as a nonlinear optical device in the field of:

* second harmonic generation 946 nm.

* Electro – optical modulation.

* Optical parametric oscilation

* Phase conjugated reflection

* Other photorefractive device.

2.     Main properties:

Crystal structure: orthorhombic

Point group: mm2

Cell parameters (Å) : a=5.697 b=3.971 C=5.722

Transparency range (um): 0.35 ~ 5

Hardness ( Mob’s scale): 4.5

Spontaneous Polarization (o/m) Ps =0.41+/-0.02 o/m

Density: 4.62 g/cm³

Melting point: 1050 ℃

Electro-optical coefficients: 380 +/- 50 Pm/V(r₄₂)

Laser damage threshold:> 250 MW/cm²

Nonlinear coefficients: d₃₃=27.4 +/- 0.3 Pm/V(1064 nm)

Conversion efficiency: 30% - 50%

3.     Typical size:

*  KNbO₃  crystals 3x3x1.7 mm for SHG 946 nm

theta = 31.2 degree,phi =  90 degree.

     *  KNbO₃ FOR SHG 930 ,3x3x8mm,Type I, AR/AR930+465nm