Fuzhou Caston Optronics Co.,Ltd

I. Introduction

As one of KTP’s isomorphs, Potassium Titanyl Arsenate (KTiOAsO₄ or KTA) is an excellent NLO crystal developed recently for NLO devices and E-O applications.

Compared to KTP crystal, KTA crystal has stable chemical and thermal properties, broad angular and temperature bandwidths, but features wider transparency range, higher NLO & E-O coefficients, significantly reduced idler absorption, lower dielectric constants, higher damager threshold due to lower ionic conductivities.

Based on the above significant advantages, KTA crystals are important for the applications of second harmonic generation (SHG), sum and difference frequency generation (SFG and DFG).

OPO devices based on KTA crystals are reliable, solid state sources of tunable laser radiation exhibiting energy conversion efficiencies above 50%, and often used to generate mid-IR radiations. Comparing with the limit to higher powers in KTP OPOs, KTA is a candidate for operation at high output powers due to its significantly reduced idler absorption in the region of 2.0-5.0μm.

KTA can be used in electro-optical Q-switching and modulation, based on its larger E-O coefficients.

Now KTA crystals are grown by CASTON's advanced controlled flux-growth methods which meet most stringent quality standards, and ensure us one of the largest and stable NLO devices suppliers in global market. As large as 15x15x30 mm finished KTA devices are available in CASTON. Please contact us for KTA crystals with consistent quality (top optical homogeneity, high transmission and low scattering) and unbeatable price, 1-2 weeks delivery.

II-A. Chemical and Physical properties

Crystal Structure	Orthorhombic, Point group mm2
Lattice Parameters	a=13.125Å ,b=6.5716Å, c=10.786Å; Z=8
Density	3.454 g/cm3
Mohs Hardness	~ 5
Melting Point	1130°C
Curie Point	880°C
Specific Heat	0.687 cal/goC (25oC)
Dielectric Constant	eeff =42
Absorption Coefficient	<0.05%/cm @1.064μm and 0.532μm
Thermal Conductivity	18 W/m/oC
Electrical Conductivity	0.7-3.4 x10-6s/cm (c-axis, 22oC, 2KHz)
Color	Colorless
Hygroscopic Susceptibility	No

II-B. Optical and NLO Properties

Transparency Region

350nm ~ 5.5μm

Nonlinear Coefficients

(@1.064μm)

d₃₁=2.76 pm/V, d₃₂=4.74 pm/V, d₃₃=18.5 pm/V

d₂₄=3.2 pm/V, d₁₅=2.3 pm/V

d_eff(ll)≈(d₂₄-d₁₅)sin2fsin2q -(d₁₅sin²f+d₂₄cos²f)sinq

Refractive Indexes

n_x	n_y	n_z
1.7830	1.7893	1.8679	(@ 1.064μm)
1.8298	1.8359	1.9310	(@ 0.532μm)

Sellmeier Equations

(l in μm)

n_x² = 1.90713+1.23522l²/(l²-0.19692)-0.01025l²

n_y² = 2.15912+1.00099l²/(l²-0.21844)-0.01096l²

n_z² = 2.14768+1.29559l²/(l²-0.22719)-0.01436l²

Electro-optic coefficients

g₁₃=11.5pm/V, g₂₃=15.4pm/V, g₃₃=37.5pm/V

SHG PM range

1.083μm ~ 3.789μm

Damage Threshold

> 1.5 GW/ cm² at 1.064μm, 10 ns

III.Standard Fabrication specifications

Transparency Region

350nm ~ 5.5μm

Nonlinear Coefficients

(@1.064μm)

d31=2.76 pm/V, d32=4.74 pm/V, d33=18.5 pm/V

d24=3.2 pm/V, d15=2.3 pm/V

deff(ll)≈(d24-d15)sin2fsin2q -(d15sin2f+d24cos2f)sinq

Refractive Indexes

nx	ny	nz
1.7830	1.7893	1.8679	(@ 1.064μm)
1.8298	1.8359	1.9310	(@ 0.532μm)

Sellmeier Equations

(l in μm)

nx2 = 1.90713+1.23522l2/(l2-0.19692)-0.01025l2

ny2 = 2.15912+1.00099l2/(l2-0.21844)-0.01096l2

nz2 = 2.14768+1.29559l2/(l2-0.22719)-0.01436l2

Electro-optic coefficients

g13=11.5pm/V, g23=15.4pm/V, g33=37.5pm/V

SHG PM range

1.083μm ~ 3.789μm

Damage Threshold

> 1.5 GW/ cm2 at 1.064μm, 10 ns