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The KTP crystal Photox supplies is flux grown and fabricated under strict quality control. KTP has many favourable features that enable it to be widely used for frequency doubling (SHG) of Nd-doped lasers for Red/Green output, for mixing of Nd-doped lasers and diode lasers for Blue output, and for OPO and OPA, for 0.6µm-4.5µm tunable output. It is also used for many E-O devices such as optical waveguides, optical switches, directional couplers and E-O modulators.
 | Large nonlinear optical coefficient |
| High electro-optic coefficient and low dielectric constant |
| Large figure of merit for optical waveguide modulator application |
| Wide angular bandwidth |
| Small walk-off angle |
| Broad temperature and spectral bandwidth |
| Non-hygroscopic |
| Good chemical and mechanical properties |
Physical Properties |
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| Crystal structure | orthorhombic |
| Point group | m2m |
| Lattice parameters | a=6.420 Å, b=10.604 Å, c=12.809 Å, z=8 |
| Melting point | 72 °C incongruent |
| Mohs hardness | 5 |
| Density | 3.01 g/cm3 |
| Specific heat | 0.1737 cal/g °C |
| Curie point | 936 °C |
| Thermal conductivity | 0.13 W/cm/°K |
| Electrical conductivity | 3.5 x 10-8 s/cm (c-axis, 22°C, 1KHz) |
| Colour | colourless |
Optical and NLO Properties |
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| Transmitting range | 0.35µm-4.5µm | ||||||||||||
| Refractive indices |
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| Sellmeier equations | (l in mm) nx2=3.0065+0.03901/(l2- 0.04251) - 0.01327 l2 ny2=3.0333+0.04154/(l2- 0.04547) - 0.01408 l2 nz2=3.3134+0.05694/(l2- 0.05658) - 0.01682 l2 |
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| Effective SHG coefficient | 8.3 x d36 (KDP) for SHG @ 1064 nm | ||||||||||||
| Phase matchable range | 0.984-3.4 µm | ||||||||||||
| Absorption coefficient | a< 1%/cm @1.064 mm/ 0.532mm | ||||||||||||
| Conversion efficiency | 45-80% | ||||||||||||
| Laser damage threshold | 450 MW/cm2 | ||||||||||||
| Dielectric constant | Eeff=13 | ||||||||||||
Finished Quality Indications |
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| End faces flatness | l/8 @633nm |
| Transmitting wavefront distortion | >l/4 @633nm |
| Scratch/Dig | 10/5 |
| Clear aperture | >90% central area |
| Dimensional tolerance | W±0.1mm x H±0.1mm x L+0.2mm/-0mm |
| Parallelism | better than 20 arc sec. |
| Perpendicularity | 5 arc min. |
| Angular tolerance | Dq<0.5o, Df<0.5o |
AR-coating for 1064nm/532nm dual band with residual reflectivity <0.1% @ 1064nm and <0.4% @ 532nm per face. Other coatings are also available. Mounts can be provided free of charge.
Note that KTP's damage threshold only allows it to be used for medium and relatively low power lasers. Its polished surfaces need to be handled with care, avoid scratching and dust. Technical advice will be freely provided when the parameters of the user's laser and application are given.