KTP crystal is mostly used as nonlinear crystals for frequency doubling of solid-state Nd:YAGcrystal or Nd:YVO4 crystal laser, as it has large nonlinear optical coefficients, wide angular bandwidth and small walk-off angle, broad temperature and spectral bandwidth. KTP crystal alsohas high electro-optic (E-O) coefficient and low dielectric constant, and large figure of merit,these features make it also widely used in electro-optic application.
Advantages
Large Nonlinear Optical (NLO) Coefficients
Wide Angular Bandwidth and Small Walk-off Angle
Broad Temperature and Spectral Bandwidth
High Electro-Optic (E-O) Coefficient and Low Dielectric Constant
Large Figure of Merit for an Optical Waveguide Modulator
Nonhygroscopic, Good Chemical and Mechanical Properties
Capabilities:
Aperture:
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2x2 ~ 10x10mm
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Long:
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0.1 - 20mm
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Cutting Angle q and f:
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Determined by different kinds of homonic generartion
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Phase matching type:
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Type I or Type II
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End Configuration:
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Plano/Plano or Brewst/Brewst or Specified
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Specifications:
Angle tolerance:
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Δθ< ± 0.5°; Δφ< ±0.5°
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Dimensional Tolerance:
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(W ± 0.1mm) x (H ± 0.1mm) x (L + 0.2mm/-0.1mm)
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Flatness:
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<λ/8 at 633nm
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Surface Quality:
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10/5 Scratch/Dig
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Parallelism:
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< 20 arc seconds
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Perpendicularity:
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< 5 arc minutes
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Wave front Distortion:
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<λ/8 at 632.8nm
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Clear Aperture:
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Central 95%
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Chamfer:
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0.15x45°
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Coating:
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a) * S1,S2: AR @ 1064 nm R<0.1% & 532nm R<0.25%
b) * S1:HR @ 1064nm R>99.8% & HT@ 808nm T>95%
S2:AR @ 1064 nm R<0.1% & 532nm R<0.25%
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Properties:
Crystal structure
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Orthorhombic, point group mm2
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Melting point
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1172°C incongruent
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Cell parameters
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a=6.404?, b=10.616?, c=12.814?, Z=8
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Curie point
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936°C
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Mohs hardness
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~5
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Density
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3.01 g/cm3
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Color
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colorless
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Hygroscopic susceptibility
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no
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Specific heat
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0.1643 cal/g.°C
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Thermal conductivity
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0.13 W/cm/°K
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Electrical conductivity
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3.5x10-8 s/cm (c-axis, 22°C, 1KHz)
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Transmitting range
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350nm~4500nm
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Refractive indices
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-
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nx
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ny
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nz
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1064nm
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1.7377
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1.7453
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1.8297
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532nm
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1.7780
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1.7886
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1.8887
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Absorption coefficients
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a < 1%/cm @1.064μ m and 0.532μ m
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Phase match range
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0.984 - 3.4 μ m
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Therm-optic coefficients
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dnx/dT=1.1x10-5/°C, dny/dT=1.3x10-5/oC, dnz/dT=1.6x10-5/°C
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Nonlinear optical coefficients
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d31=2.54pm/V, d31=4.35pm/V, d31=16.9pm/V
d24=3.64pm/V, d15=1.91pm/V at 1.064 mm
deff(II)≈ (d24 - d15)sin2fsin2q - (d15sin2f + d24cos2f)sinq
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Electro-optic coefficients
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-
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Low frequency(pm/V)
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High frequency(pm/V)
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g13
g23
g33
g51
g42
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9.5
15.7
36.3
7.3
9.3
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8.8
13.8
35.0
6.9
8.8
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Dielectric constant
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eeff=13
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Sellmeier equations
nx2=3.0065+0.03901/(l2-0.04251)-0.01327l2
ny2=3.0333+0.04154/(l2-0.04547)-0.01408l2
nz2=3.3134+0.05694/(l2-0.05658)-0.01682l2