Potassium Titanium Oxide Phosphate (KTiOPO4 ), or KTP, is an
efficient nonlinear optical crystal in the visible to infrared spectral region
with relatively low cost. It has large nonlinear coefficient. The effective
nonlinear optical coefficient of KTP deff at 1064nm is more than 1.5 times that
of BBO. It's damage threshold is near 1 GW/cm2 for 1 Hz 10 ns pulses
at 1064nm. However, it is now limited to moderate to low power applications due
to it's gray-tracking problem. Recently we have developed gray-tracking-improved
KTP (i-KTP) which has
significantly raised the gray-tracking trigger power.
Advantage:
-
Efficient frequency conversion(1064nm SHG
conversion efficiency is about 80%)
-
Large nonlinear optical coefficients(15
times that of KDP)
-
Wide angular bandwidth and small walk-off
angle
-
Broad temperature and spectral bandwidth
-
High thermal conductivity (2 times that of
BNN crystal )
-
Moisture free
-
Minimum mismatch
gradient
-
Super-polished
optical surface
-
No
decomposition below 900�C
-
Mechanically
stable
-
Low cost compare with BBO and LBO
Disadvantage:
Additional applications for KTP include mixed frequency,
electro-optical modulation, optical parametric generation and optical waveguide.
Application:
-
Frequency Doubling
(SHG)
of Nd-doped Lasers for Green/Red Output
-
Frequency Mixing
(SFM) of
Nd Laser and Diode Laser for Blue Output
-
Parametric Sources
(OPG,
OPA and OPO) for 0.6mm-4.5mm Tunable Output
-
Electrical
Optical(E-O)
Modulators, Optical Switches, and Directional Couplers
-
Optical Waveguides for
Integrated NLO and E-O Devices
Main Specifications
|
|
Dimension |
1x1x0.05 - 30x30x40
mm |
Phase
matching type |
Type II, θ=90�;
φ=phase-matching angle |
Typical Coating |
a) S1&S2: AR
@1064nm R<0.1%; AR @ 532nm, R<0.25%.
b) S1: HR @1064nm, R>99.8%; HT @808nm, T>5% S2: AR @1064nm,
R<0.1%; AR @532nm, R<0.25%
Customized coating available upon customer request. |
Angle tolerance |
6'
Δθ< � 0.5�; Δφ< �0.5� |
Dimension tolerance |
�0.02 - 0.1 mm
(W � 0.1mm) x (H � 0.1mm) x (L + 0.2mm/-0.1mm) for NKC series |
Flatness |
λ/8 @ 633nm |
Scratch/Dig code |
10/5 Scratch/dig per MIL-O-13830A |
Parallelism |
<10'
better than 10 arc seconds for NKC series |
Perpendicularity |
5'
5 arc minutes for NKC series |
Wavefront distortion |
less than λ/8 @ 633nm |
Clear aperture |
90% central area |
Working temperature |
25�C - 80�C |
Homogeneity |
dn
~10-6/cm |
|
Note:
To inquire or order a
finished KTP crystals, please provide detailed specifications as listed in the above. We require engineering drawing for
specific orientation.
For special applications, please consult us for the
designs if you are sure about the phase matching angle .
Physical and
Chemical Properties
|
Crystal
structure |
Orthorhombic |
Point group |
mm2 |
Melting
point |
1172�C
incongruent |
Lattice parameters |
a=6.404�, b=10.615�, c=12.814�, Z=8 |
Temperature of decomposition |
~1150�C
|
Transition temperature |
936�C |
Mohs
hardness |
~5 |
Density |
2.945 g/cm3 |
Color |
colorless |
Hygroscopic
susceptibility |
no |
Specific
heat |
0.1737
cal/g.�C |
Thermal
conductivity |
0.13 W/cm/�C |
Electrical
conductivity |
3.5x10-8 s/cm (c-axis, 22�C,
1KHz) |
Thermal expansion coefficients |
a1 = 11 x 10-6
�C-1
a2 = 9 x 10-6 �C-1
a3 = 0.6 x 10-6 �C-1
|
Thermal
conductivity coefficients |
k1 = 2.0 x 10-2
W/cm �C
k2 = 3.0 x 10-2 W/cm �C
k3 = 3.3 x 10-2 W/cm �C
|
Dielectric constant |
eeff
= 13 |
Optical Properties |
|
Transmitting
range |
350nm
~ 4500nm |
Refractive
indices |
|
nx |
ny |
nz |
1064nm |
1.7400 |
1.7469 |
1.8304 |
532nm |
1.7787 |
1.7924 |
1.8873 |
Absorption
coefficients |
a
< 1%/cm @1064nm and 532nm |
Therm-optic
coefficients |
dnx/dT=1.1x10-5/�C
dny/dT=1.3x10-5/�C
dnz/dT=1.6x10-5/�C |
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 |
|
Sellmeier equations |
nx2=2.10468
+ 0.89342λ2/(λ2-0.04438)-0.01036λ2
ny2=2.14559 + 0.87629λ2/(λ2-0.0485)-0.01173λ2
nz2=1.9446 + 1.3617λ2/(λ2-0.047)-0.01491λ2 |
Nonlinear
Properties |
|
Phase
matching range |
497nm
� 3300 nm |
Nonlinear
coefficients
(@ 10-64nm) |
d31=2.54pm/V,
d31=4.35pm/V, d31=16.9pm/V d24=3.64pm/V,
d15=1.91pm/V at 1.064 mm |
Effective nonlinear
optical coefficients |
deff(II)≈ (d24 - d15)sin2qsin2j
- (d15sin2j +
d24cos2j)sinq
|
Type
II SHG of 1064nm Laser |
Phase
matching
angle |
q=90�,
f=23.2�
|
Effective nonlinear
optical coefficients |
deff
�
8.3 x d36(KDP)
|
Angular
acceptance |
Dθ=
75 mrad Dφ=
18 mrad |
Temperature
acceptance |
25�C.cm
|
Spectral
acceptance |
5.6
�cm |
Walk-off
angle |
1
mrad |
Optical
damage threshold |
1.5-2.0MW/cm2 |
|
|