Potassium Titanyle Arsenate

Material
KTA

 

Potassium Titanyle Arsenate crystals (KTA) crystals feature large non-linear optical and electro-optical coefficients in comparison to KTP and have the added benefit of significantly reduced absorption in the 2.0µm- 5.0µm region. The large non-linear coefficients are combined with broad angular and temperature bandwidths. Additional advantages of the Arsenates are low dielectric constants, low loss tangent and ionic conductivities orders of magnitude less than KTP. Single crystals of these Arsenates are chemically and thermally stable, non-hygroscopic and are highly resistant to high intensity laser radiation.

 

KTA is used for second harmonic generation (SHG), sum and difference frequency generation (SFG)/(DFG), optical parametric oscillation (OPO), electro-optical Q-switching and modulator and as substrates for optical waveguides. OPO devices based on these crystals are reliable solid-state sources of tunable laser radiation exhibiting energy conversion efficiencies above 50%.

 

KTA has a very high damage threshold. No optical damage was observed at levels 10GW/cm2 – 20GW/cm2 with picosecond dye lasers. This crystal is grown using high temperature flux technique.

Properties
Optical properties
Transmission range
350 ‐ 5500
Refractive index @ 1064 nm
nx = 1,782

ny = 1,790

nz = 1,868

Average refractive index
1,8
NLO coefficients in pm/V
d15 = 2,3

d24 = 3,2

d31 = 2,8

d32 = 4,2

d33 = 16,2

Absorption loss in %/cm @532 nm and @1355 nm
<0,05
Absorption loss in %/cm @ 3475 nm
<5
Phase matching range in nm
1075 ‐ 1134
Wavelength in nm:
Pumpe ⇒ 1064

Signal ⇒ 1533

Idler ⇒ 3475

Damage threshold in MW/cm2 (1064 nm, 10 ns, 10 Hz)
600
Electro-optical constants (low frequency) in pm/V
r33 = 37,5

r23 = 15,4

r13 = 11,5

Physical properties
Chemical formula
KTiOAsO4
Density in g/cm3
3,454
Melting point in °C
1130
Lattice constants in Å
a= 13,125

b = 6,5716

c = 10,786

Crystal structure
orthorhombic
Hygroscopic susceptibility
no
Thermal conductivity in W/(m·K)
k1 = 18

k2 = 19

k3 = 21

Mohs hardness
3
Spectral properties
sample thickness: 10 mm