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         List of Products             KTP Crystals
  • large nonlinear optical coefficient
  • wide angular bandwidth and small walk-off angle
  • broad temperature and spectral bandwidth
  • high electro-optic coefficient and low dielectric constant
  • large figure of merit
  • nonhydroscopic, chemically and mechanically stable


  • 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 600nm-4500nm tunable output.
  • E-O modulators, optical switches, directional couplers.
  • optical waveguides for integrated NLO and E-O devices.

Using advanced technique in crystal growth, 35x55x68mm3 transparent KTP boule with flux method has been grown. As large as 15x15x20mm3 KTP devices are fabricated.

We provide KTP with:

  • strict quality control on optical homogeneity, transmission and scattering
  • quick delivery
  • unbeatable price and quantity discount
  • technical support
  • AR-coating, mounting and re-polishing service

Structural and Physical Properties:

Crystal structure

Orthorhombic, space group Pna21,point group mm2

Cell parameters

a=6.404 Angstrom, b=10.616 Angstrom, c=12.814 Angstrom, Z=8

Melting point

1172 C incongruent

Curie point

936 C

Mohs hardness



3.01 g/cm3



Hygroscopic susceptibility


Specific heat

0.1643 cal/gC

Thermal conductivity

0.13 W/cm/K

Electrical conductivity

3.5x10-8 s/cm (c-axis, 22 C, 1KHz)

 Nonlinear Optical Properties:

Phase matchable SHG range:

497 - 1800nm

Nonlinear optical coefficients:

d31=6.5pm/v, d32=5pm/v, d33=13.7pm/v, d24=7.6pm/v, d15=6.1pm/v

deff(II) (d24 - d15)sin2f sin2q - (d15sin2f + d24cos2f )sinq

For type II SHG of a Nd:YAG laser at 1064nm:

PM angle: q =90 , j =23.3

Effective SHG coefficient: deff 8.3xd36(KDP)

Angular acceptance: 20 mrad-cm

Temperature acceptance: 25 C-cm

Spectral acceptance: 5.6 Angstrom -cm

Walk-off angle: 4.5 mrad (0.26 )

Damage threshold: >450MW/cm2 @1064nm, 10ns, 10Hz

Electro-optic coefficients:






Low frequency (pm/V) High frequency (pm/V)

9.5 8.8

15.7 13.8

36.3 35.0

7.3 6.9

9.3 8.8

Dielectric constant:


Optical Properties:

Transmitting range:

350 nm - 4500 nm

Refractive indices:



nx ny nz

1.7377 1.7453 1.8297

1.7780 1.7886 1.8887

Therm-optic coefficients:

dnx/dT=1.1x10-5/ C, dny/dT=1.3x10-5/ C, dnz/dT=1.6x10-5/ C


a < 1% cm-1 @1064nm and 532nm


Applications for SHG and SFG of Nd:lasers

KTP is the most commonly used material for frequency doubling of Nd:YAG lasers and other Nd-doped lasers, particularly at the low or medium power density. To date, extra- and intra-cavity frequency doubled Nd:lasers using KTP have become a preferred source of pumping visible dye lasers and tunable Ti:Sapphire lasers as well as their amplifiers. Applied to diode-pumped Nd:laser, KTP has provided the basis for the construction of compact visible solid state laser systems.

Recent advances in intracavity-doubled Nd:YAG and Nd:YVO4 lasers, have increased the demand for compact green lasers used in optical disk and laser printer. Over 100mW and 76mW TEM00 green outputs are available from LD pumped Nd:YAG and Nd:YVO4 lasers, respectively. Moreover, 2.5mW green light has derived from 50mW LD pumped and intracavity doubled Nd:YVO4 mini-lasers with a 9mm long cavity.

KTP has also shown its powerful applications in extracavity SHG with conversion efficiency exceeding 60%. The applications of KTP for intracavity mixing of 810nm diode and 1064nm Nd:YAG laser to generate blue light and intracavity SHG of Nd:YAG or Nd:YAP lasers at 1300nm to produce red light are also in progress.

Applications for OPG, OPA and OPO

As an efficient OPO crystal pumped by a Nd:laser and its second harmonics, KTP plays an important role for parametric sources for tunable output from visible (600nm) to mid-IR (4500nm). KTP's OPO results in stable, continuous outputs of femtosecond pulse of 108 Hz repetition rate and miliwatt average power levels in both signal and idler output. KTP's OPO pumped by a 1064nm Nd:YAG laser has generated above 66% efficiency for degenerately converting to 2120nm.

KTP Specifications

  • Transmitting wavefront distortion: less than l /4 @ 633 nm
  • Dimension tolerance: (W 0.1 mm) x (H 0.1mm) x (L + 0.2 mm/-0.1mm)
  • Clear aperture: > 90% central area
  • Flatness: l /8 @ 633 nm
  • Scratch/Dig code: 10/5 to MIL-O-13830A
  • Parallelism: better than 20 arc seconds
  • Perpendicularity: 5 arc minutes
  • Angle tolerance: D q < 0.5 , D f < 0.5
  • AR coating: R< 0.2% at 1064nm and R<1.0% at 532 nm.

Quality Warranty Period: one year under proper use.

 Nd:YAG rod      Nd:YVO4       KTA      (Nd, Ce):YAG        Yb:YAG      Cr4+:YAG       KTP       LBO     BBO

Sintec Optronics Pte Ltd

10 Bukit Batok Crescent #07-02 The Spire Singapore 658079

Tel: +65 63167112 Fax: +65 63167113 Skype: Sintec168  Wechat: Sintec98

E-mail: sales@sintec.sg sales@SintecOptronics.com

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