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

Applications:

• 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

» 5

Density

3.01 g/cm³

Color

colorless

Hygroscopic susceptibility

no

Specific heat

0.1643 cal/g°C

Thermal conductivity

0.13 W/cm/°K

Electrical conductivity

3.5x10^-8 s/cm (c-axis, 22° C, 1KHz)

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

d_eff(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: d_eff » 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:

r₁₃

r₂₃

r₃₃

r₅₁

r₄₂

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:

e_eff=13

Transmitting range:

350 nm - 4500 nm

Refractive indices:

1064nm

532nm

n_x n_y n_z

1.7377 1.7453 1.8297

1.7780 1.7886 1.8887

Therm-optic coefficients:

dn_x/dT=1.1x10^-5/° C, dn_y/dT=1.3x10^-5/° C, dn_z/dT=1.6x10^-5/° C

Absorption

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.

  BBO        LBO        KTA