Potassium Titanyl Phosphate
KTiOPO4, KTP
Potassium Titanyl PhosphatePotassium Titanyl PhosphatePotassium Titanyl Phosphate

Structural and Physical Properties

Crystal Structure

Orthorhombic, space group Pna21, point group mm

Cell parameters

a = 6.404 Å
b = 10.616 Å
c = 12.814 Å
Z = 8

Melting Point

1172 °C incongruent

Curie Point

936 °C

Mohs hardness

≈ 5

Density

3.01 g / cm³

Color

Colorless

Hygroscopic susceptibility

No

Specific heat

0.1643 cal / g• °C

Thermal conductivity

0.13 W / cm / °K

Electrical conductivity

3.5 x 10-8 s/cm (c-axis, 22°C, 1 KHz)

Nonlinear Optical Properties

Phase matchable SHG range

497 – 1800 nm

Nonlinear optical coefficients

d31 = 6.5 pm / v
d32 = 5 pm / v
d33 = 13.7 pm / v
d24 = 7.6 pm / v
d15 = 6.1 pm / v
deff(І?І?) ≈(d24 – d15) sin2fsin2q - (d15sin²f + d24cos²f) sinq

For type II SHG of a Nd: YAG

Laser at 1064 nm

Pm angle: q = 90°C, f = 23.3°
Effective SHG coefficient: deff» 8.3 xd36 (KDP)
Angular acceptance: 20 mrad-cm
Temperature acceptance: 25 °C-cm

Spectral acceptance: 5.6 Å –cm
Walk-off angle: 4.5 mrad (0.26°)
Optical damage threshold: > 450 MW / cm², 
(@ 1064 nm, 10 ns, 10 Hz)

 

Electro – optic coefficients

Low frequency (pm/V)

High frequency (pm/V)

R13

9.5

8.8

R23

15.7

13.8

R33

36.3

35.0

R51

7.3

6.9

R42

9.3

8.8

Dielectric constant

Eeff= 13

Optical properties

Transmitting range:Density

350 – 4500 nm

 

Refractive indices
1064 nm
532 nm

nx
1.7377
1.7780

ny
1.7453
1.7886

nz
1.8297
1.8887

Sellmeier equations

nx2 = 3.0065 + 0.03901 / (l2 - 0.04251) – 0.01327 l2
ny2 = 3.0333 + 0.04154 / (l2 – 0.04547) – 0.01408 l2
nz2 = 3.0065 + 0.05694 / (l2 – 0.05658) – 0.01682 l2

Therm – optic coefficients

dnx / dT = 1.1 x 10-5 / °C
dny / dT = 1.3 x 10-5 / °C
dnz / dT = 1.6 x 10-5 / °C

Absorption coefficient

αa < 1% cm-1 @ 1064 nm and 532 nm