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  • 名称: KTP
  • 编号: 111
  • 上传时间: 2014-08-01
  • 浏览次数: 1080

Potassium Titanyl Phosphate (KTiOPO3 or KTP) is an excellent nonlinear optical material suitable for use in many optical systems. It has high nonlinear coefficient and stable physical property. Its most popular application is as a frequency doubler utilizing the 1064nm output of a Nd:YAG laser and to generate 532nm laser. KTP’s properties also make it superior for electro-optic modulation, optical parametric generation.

 

After years of development, CRYSTECH has become the largest KTP manufacturer in the world.

CRYSTECH offers

Strict quality control

large crystal size up to 20x20x40mm3 and maximum length of 60mm

Quick delivery(3 weeks for polished only, 4 weeks for coated)

reasonable price and quantity discount

Technical support

AR-coating, re-polishing service.

APPLICATION:

Due to the unique combination of its properties – high nonlinear coefficient, high damage threshold, non-hygroscopic, KTP can be used in both commercial and military lasers including medical and laboratory systems, range finders, designators and systems for use in semiconductor industry.

 

Its application includes:

 

SHG, SFG of Nd Lasers

Optical Parametric Generation (OPG, OPA, OPO)

Electro-Optical modulations

Optical waveguide for integrated NLO and E-O devices

 

 

ØSHG, 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. Extra- and intra-cavity frequency doubled Nd-lasers using KTP have become a preferred green laser source for many R&D, medical, industrial, commercial and military applications. By using extra cavity KTP SHG, over 80% conversion efficiency and 700mJ green laser were obtained with a 900 mJ injection-seeded Q-switched Nd:YAG laser.

Applied to diode-pumped Nd-lasers, KTP is a basic NLO crystal for the construction of compact visible solid state laser systems. Recent advances in intracavity-doubled Nd:YVO4 and Nd:YAG lasers have increased the demand for compact green lasers used in display, construction, optical disk and laser printer. Over 200 mw TEM00 green outputs are available from LD pumped Nd:YVO4 and Nd:YAG lasers and 3 W TEM00, mode-locked green laser was generated by intracavity SHG in a 5.3 W mode-locked diode-laser pumped Nd:YAG laser. Moreover, 2.5mW green light was obtained from 50mW LD pumped and intracavity doubled Nd:YVO4 mini-lasers with a 9mm long cavity.

KTP is also a powerful crystal for SHG and SFG of lasers with wavelength from about 1um to 3.4 um. The SHG phase-matching angle and effective SHG coefficients (deff) of KTP in XY plane (0.9 mm to 1.08 mm) and XZ plane (1.1 um to 3.3 um) are showed in the following figures. Although KTP cut in YZ plane can be phase-matched for SHG of 1 mm to 3.45 um, it is seldom used in practices because of the low deff.

ØOptical Parametric Generation (OPG, OPA, OPO)

 

As an efficient OPO crystal pumped by the fundamental and second harmonics of a Nd:YAG or Nd:YLF laser, KTP plays an important role in parametric sources for tunable output from visible (0.6 um) to mid-IR (4.5 um). In NCPM KTP OPO pumped by 1064 nm, the signal output is around eye safe wavelength, finding applications in eye-safe devices. KTP's OPO pumped by a 1064 nm Nd-laser has generated above 66% conversion efficiency for conversion from 1064 to 2120 nm. The OPO/OPA in XY and YZ is seldom employed because of their low effective nonlinear coefficients and other limitation.

Below figure shows the non-critical phase-matched (NCPM) X-cut KTP OPO/OPA. For pumping wavelength range from 0.7μm to 1 μm, the output can cover from 1.04μm to 1.45μm(signal) and from 2.15μm to 3.2μm(idler). More than 45% conversion efficiency was obtained with narrow output bandwidth and good beam quality.

ØElectro-Optical Modulation

 

KTP also has promising E-O and dielectric properties that are comparable to LiNbO3. These properties make KTP extremely useful in various E-O devices.

  

 

   
 

Oven for Heating KTP crystals

 

Increasing the temperature of KTP crystal can enhance the damage threshold of KTP crystal. Therefore, for high power or high power density SHG of Nd lasers, heating KTP to a certain temperature (e.g., 80~100deg) is recommended. CRYSTECH provides precision oven with temperature controller for heating KTP. A full assembly including KTP crystal, oven and temperature controller is also available.

ADVANTAGE:

Large nonlinear coefficient

Wide angular bandwidth and small walk off angle

Broad temperature and spectral bandwidth

Large electro-optical coefficient

High damage threshold

Nonhygroscopic, chemically and mechanically stable

Dimension Tolerance

W(+/-0.1)*H(+/-0.1)*L(+0.5/-0.1)mm

Angle Tolerance

+/-0.25°

Perpendicularity

10′

Scratch/Dig

20/10

Chamfer

0.2mmx45°

Parallelism

10″

Chips

0.1mm

Flatness

λ/10@633nm

Clear Aperture

90%

Wavefront distortion

λ/8@633nm

 

Coatings

C1---AR@1064(R<0.2%)&532(R<0.5%)

C2---HR@1064(R>99.8%)&HT@532(T>95%)

C3---AR@1064(R<0.2%)&1570(R<0.5%)

C4---HR@1570(R>99.8%)&HT@1064(T>99.5%)

C5---HR@1064(R>99.8%)&PR@1570(R=50,60,70%+/-2%)

Damage Threshold

500MW/cm² (1064nm, 10ns, 10Hz)

 

 

P/N

Type

Size(mm)

P/N

Type

Size(mm)

KTP-Y-225-C1/C1

SHG

2x2x5

KTP-X-3310-C4/C5

OPO

3x3x10

KTP-Y-2210-C1/C1

SHG

2x2x10

KTP-X-3320-C3/C3

OPO

3x3x20

KTP-Y-335-C1/C1

SHG

3x3x5

KTP-X-3320-C4/C3

OPO

3x3x20

KTP-Y-3310-C1/C1

SHG

3x3x10

KTP-X-3320-C4/C5

OPO

3x3x20

KTP-Y-445-C1/C1

SHG

4x4x5

KTP-X-4416-C3/C3

OPO

4x4x16

KTP-Y-4410-C1/C1

SHG

4x4x10

KTP-X-4416-C4/C3

OPO

4x4x16

KTP-Y-555-C1/C1

SHG

5x5x5

KTP-X-4416-C4/C5

OPO

4x4x16

KTP-Y-5510-C1/C1

SHG

5x5x10

KTP-X-4420-C3/C3

OPO

4x4x20

KTP-Y-663-C1/C1

SHG

6x6x3

KTP-X-4420-C4/C3

OPO

4x4x20

KTP-Y-665-C1/C1

SHG

6x6x5

KTP-X-4420-C4/C5

OPO

4x4x20

KTP-Y-668-C1/C1

SHG

6x6x8

KTP-X-5520-C3/C3

OPO

5x5x20

KTP-Y-775-C1/C1

SHG

7x7x5

KTP-X-5520-C4/C3

OPO

5x5x20

KTP-Y-778-C1/C1

SHG

7x7x8

KTP-X-5520-C4/C5

OPO

5x5x20

KTP-Y-885-C1/C1

SHG

8x8x5

KTP-X-6620-C3/C3

OPO

6x6x20

KTP-Y-888-C1/C1

SHG

8x8x8

KTP-X-6620-C4/C3

OPO

6x6x20

KTP-Y-995-C1/C1

SHG

9x9x5

KTP-X-7720-C3/C3

OPO

7x7x20

KTP-Y-996-C1/C1

SHG

9x9x6

KTP-X-7720-C4/C3

OPO

7x7x20

KTP-Y-10105-C1/C1

SHG

10x10x5

KTP-X-8820-C3/C3

OPO

8x8x20

KTP-Y-10106-C1/C1

SHG

10x10x6

KTP-X-8820-C4/C3

OPO

8x8x20

 

KTP is a positive biaxial crystal, with the principal axes X, Y, and Z (nz>ny>nx) parallel to the crystallographic axes a, b, and c, respectively.

Physical Properties:

 

Crystal structure

Orthorhombic, space group Pna21,point group mm2

Cell parameters

a=6.404Å, b=10.616Å, c=12.814Å, Z=8

Melting point

Around 1172

Mohs hardness

5

Density

3.01 g/cm3

Color

colorless

Hygroscopic susceptibility

no

Thermal conductivity

0.13 W/(cm*K-1)

Thermo-optic Coefficient

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

Absorption coefficient

<0.1%/cm @ 1064nm, <1%/cm @ 532nm

 

 

Optical Properties:

 

 

Transmitting range:

350 nm - 4500 nm

SHG Phase Matchable Range

4971800nm  (Type II)

Refractive indices: 

           1064nm

           532nm

 nx           ny          nz

1.7377   1.7453   1.8297

1.7780   1.7886   1.8887

Sellmeier equations:

(λ in μm)

nx2=3.0065+0.03901/(λ2-0.04251)-0.01327λ 2
ny2=3.0333+0.04154/(λ 2-0.04547)-0.01408λ2
nz2=3.3134+0.05694/(λ 2-0.05658)-0.01682λ2

Nonlinear optical coefficients:

d31=6.5pm/v,

d32=5pm/v,

d33=13.7pm/v,

d24=7.6pm/v,

d15=6.1pm/v

Effective nonlinearity expressions

deff(II) (d24 - d15)sin2sin2 - (d15sin2 + d24cos2)sin

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

PM angle:  =90°,  =23.5°

Effective SHG coefficient:  deff8.3d36(KDP)

Angular bandwidth: 14.2mrad-cm (φ); 55.3mrad-cm (θ)

Temperature bandwidth: 25-cm

Spectral bandwidth: 5.6 Å -cm

Walk-off angle: 0.55°

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

Dielectric constant:

eff=13