KTP Nonlinear Crystal

Typical Features of KTP crystal:

Efficient frequency conversion(1064nm SHG conversion efficiency is about 80%)
Large nonlinear optical coefficients(15 times that of KDP)
Wide angular bandwidth and small walk-off angle
Broad temperature and spectral bandwidth
High thermal conductivity (2 times that of BNN crystal )
Moisture free
Minimum mismatch gradient
Super-polished optical surface
No decomposition below 900°C
Mechanically stable
Low cost compare with BBO and LBO

Disadvantage:

Gray-tracking at high power limited its application to moderate power density
Additional applications for large size GTR-KTP nonlinear crystal include mixed frequency, electro-optical modulation, optical parametric generation, and the optical waveguide.

High damage threshold KTP nonlinear crystal is widely used in frequency doubling of Nd-doped laser systems for Green/Red 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 etc.

SHG of Nd: lasers
Custom high purity KTP nonlinear crystal 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. The following table lists the major NLO properties of KTP for frequency-doubling of an Nd: YAG laser.

Extra- and intra-cavity frequency doubled Nd: lasers using high quality Chinese KTP nonlinear crystal have become a preferred green laser source for many R&D, medical, industrial, and commercial applications. By using extra-cavity KTP SHG, a conversion efficiency of over 80%  and 700 mg green power were obtained with a 900 mg injection-seeded Q-switched Nd: YAG laser.
OPG, OPA, and OPO

As an efficient OPO crystal pumped by the fundamental and second harmonics of an Nd: YAG or Nd: YLF laser, custom high purity KTP nonlinear crystal plays an important role in parametric sources for tunable output from visible (0.6 um) to mid-IR (4.5 um). The non-critical phase-matched (NCPM) OPO/OPA with an X-cut KTP pumped by 1064nm is particularly useful as the signal output @1.57 um is eye safe.  NCPM KTP OPO/OPA pumped by the tunable lasers such as Ti: Sapphire, Alexandrite, and Cr: LiSrAlF6 have also been reported with high efficiency of 45%.

Chemical and Structural Properties

E-O Devices:

In addition to unique NLO features, large size GTR-KTP nonlinear crystal also has promising E-O and dielectric properties that are comparable to LiNbO3. These advantaged properties make KTP extremely useful to various E-O devices. KTP is expected to replace LiNbO3 crystal in the considerable volume application of E-O modulators, when other merits of KTP are combined into account, such as high damage threshold, wide optical bandwidth (>15GHZ), thermal and mechanical stability, and low loss, etc.

Optical Waveguides:

Based on the ion-exchange process on KTP substrate, low loss optical waveguides developed for KTP have created novel applications in integrated optics. Recently, a type II SHG conversion efficiency of 20%/W/cm2 was achieved by the balanced phase matching, in which the phase mismatch from one section was balanced against a phase mismatch in the opposite sign from the second. Furthermore, segmented KTP waveguides have been applied to the type I quasi-phase-matchable SHG of a tunable Ti: Sapphire laser in the range of 760-960mm, and directly doubled diode lasers for the 400-430nm outputs.

Physical and optical properties:

Honour Optics provides the following KTP coatings：

Dual Band AR-coating (DBAR) of KTP for SHG of 1064nm.
Broad Band AR-coating (BBAR) of KTP for OPO applications.
High reflectivity coating: HR1064nm&HT532nm, R>99.8%@1064nm, T>90%@532nm.
Other coatings are available upon request.

Honour Optics standard specifications for KTP crystal
Dimension tolerance：(W±0.05)x(H±0.05)x(L+ /-0.1mm)
Clear aperture: central 90% of the diameter
No visible scattering paths or centers when inspected by a 50mW green laser
Flatness: less than λ/8 @ 633nm
Transmitting wavefront distortion: less than λ/8 @ 633nm Chamfer: ≤0.2mm@45°
Chip:≤0.1mm
Scratch/Dig code: better than 10/ 5（MIL-PRF-13830B）
Parallelism: better than 20 arc seconds
Perpendicularity: ≤5 arc minutes
Angle tolerance: △θ≤0.25°, △ф≤0.25°
Damage threshold (GW/cm2)：
>0.5 for 1064nm, TEM00, 10ns, 10HZ (AR-coated)
>0.3 for 532nm, TEM00, 10ns, 10HZ (AR-coated)

We can customize crystal angle and size except for standard specification according to your request. It is available to re-polishing and coating for KTP crystals that you supply to us. Honour Optics is the professional high damage threshold KTP nonlinear crystal manufacturer, purchasing large size KTP nonlinear crystal at factory price.

Standard applications of KTP crystal:

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 0.6mm-4.5mm Tunable Output
Electrical Optical(E-O) Modulators, Optical Switches, and Directional Couplers
Optical Waveguides for Integrated NLO and E-O Devices

Honour Optics Warrant:

Strict quality control;
High inside quality without any defection.
Large crystal size up to 20x20x40mm3 and maximum length of 60mm;
Quick delivery (2 weeks for polished only, 3 weeks for coated);
Unbeatable price and quantity discount;
Technical support;
AR-coating, mounting and re-polishing service.
Quality Warranty Period: one year under proper use.

Honour Optics offers high-quality KTP and GTR-KTP crystal, size upon your request, and provide AR-coating, mounting and re-polishing service.

Honour Optics offers standard KTP crystal within 4-5 weeks