POC-OC-122407-GTR-KTP Crystal

  • High gray tracking resistance, making it ideal for high repetition rate and high-power laser systems.
  • Superior damage threshold compared to conventional KTP crystals, ensuring reliability in demanding applications.
  • Optimized for second harmonic generation (SHG), optical parametric oscillators (OPO), and other nonlinear optical applications.
  • Enhanced bulk absorption properties, reducing IR absorption and improving overall optical performance.
  • Precision fabrication with strict quality control for dimensions, coatings, and surface flatness.

Customizable Components Available for This Material to Meet Your Specific Needs!

 Material General Description of  GTR-KTP Crystal

Gray Tracking Resistance Potassium Titanyl Phosphate (GTR-KTP) crystals are advanced nonlinear optical materials engineered to overcome the limitations of conventional KTP crystals, particularly their susceptibility to gray tracking. This phenomenon leads to increased IR absorption, reducing the efficiency and lifespan of the crystal in high-power laser systems. GTR-KTP crystals, developed with innovative manufacturing processes, exhibit significantly higher resistance to gray tracking and lower absorption in the UV and visible regions, making them suitable for a wide range of applications such as frequency doubling, parametric oscillation, and laser amplification.

GTR-KTP crystals maintain the desirable properties of conventional KTP, such as a high nonlinear optical coefficient, wide angular and temperature bandwidths, and low walk-off angle. Additionally, these crystals boast a higher laser damage threshold, making them reliable for high-energy and high-repetition laser applications. These unique properties, combined with high durability and chemical stability, position GTR-KTP crystals as a superior choice for industrial, scientific, and medical laser systems.

General Applications and Examples

GTR-KTP crystals are widely utilized in applications that demand high-performance nonlinear optical materials with improved durability and resistance to gray tracking. Some notable applications include:

  1. Laser Frequency Doubling (SHG):
  • The  crystals are commonly used to double the frequency of Nd:YAG and Nd:YVO₄ lasers, generating visible green laser output (532 nm) from the fundamental 1064 nm wavelength.
  • Example: Efficient SHG processes with improved damage thresholds for high-power continuous-wave (CW) and pulsed laser systems.
  1. Optical Parametric Oscillators (OPO):
  • The crystals are integral to optical parametric oscillators for generating tunable laser outputs in the visible and near-infrared (IR) ranges.
  • Example: Tunable outputs covering wavelengths from 700 nm to 4500 nm, utilized in scientific research and spectroscopy.
  1. Medical and Biomedical Applications:
  • The crystals are used in medical lasers for procedures such as laser surgery, tattoo removal, and skin resurfacing, where stable and reliable laser performance is essential.
  1. High-Power Laser Systems:
  • Ideal for high-repetition-rate lasers, GTR-KTP crystals are employed in laser-based industrial machining, precision cutting, and marking systems.
  1. Spectroscopy and Imaging:
  • With their broad spectral range and low IR absorption, GTR-KTP crystals are well-suited for spectroscopic instruments and advanced imaging technologies.

GTR-KTP’s unique properties ensure higher conversion efficiencies, longer crystal lifespans, and reduced maintenance, making them a preferred choice for demanding applications.

Chemical and Structural Properties

Property

Specification

Crystal Structure

Orthorhombic, Space group Pna2₁

Lattice Parameters

a = 6.404 Å, b = 10.616 Å, c = 12.814 Å

Density

3.01 g/cm³

Melting Point

Approximately 1172 °C

Thermal Expansion Coefficients

a₁ = 11 × 10⁻⁶/°C, a₂ = 9 × 10⁻⁶/°C, a₃ = 0.6 × 10⁻⁶/°C

Thermal Conductivity

13 W/m·K

Chemical Stability

Non-hygroscopic, resistant to environmental degradation

Optical and Nonlinear Optical Properties

Property

Specification

Transparency Range

350–4500 nm

SHG Phase Matching Range

497–1800 nm (Type II)

Nonlinear Coefficients (pm/V)

d₃₁ = 6.5, d₃₂ = 5.5, d₃₃ = 13.7

Damage Threshold

>1.8 GW/cm² at 1064 nm (10 ns, 1 Hz)

Walk-off Angle

0.55° at 1064 nm

Absorption Coefficients

<0.1% at 1064 nm, <1% at 532 nm

Refractive Index (n)

nₓ = 1.807, nᵧ = 1.841, n𝓏 = 1.899

Thermal-Optic Coefficients (°C⁻¹)

dnₓ/dT = 1.1 × 10⁻⁵, dnᵧ/dT = 1.3 × 10⁻⁵, dn𝓏/dT = 1.6 × 10⁻⁵

Standard Fabrication Specifications

Parameter

Specification

Dimension Tolerance

±0.1 mm × ±0.1 mm × ±0.1 mm

Angle Tolerance

Δθ < 0.25°, Δφ < 0.25°

Surface Quality

10/5 to MIL-PRF-13830B

Flatness

λ/8 @ 633 nm

Parallelism

<20 arc seconds

Perpendicularity

<15 arc minutes

Clear Aperture

>90% of the diameter

Damage Threshold

>1 GW/cm² @ 1064 nm, >0.3 GW/cm² @ 532 nm

Warranty

One year under proper use

Spectrum Transmission Curve:

  • The transmission curves illustrate low absorption in the visible and UV regions, ensuring high optical transmission and efficiency for SHG and OPO processes.

Coating Specification:

  • Base Material

    AR Coating

    Reflectance

    GTR-KTP

    Dual Band AR (1064/532 nm)

    R < 0.2% @ 1064 nm, R < 0.5% @ 532 nm

     

    HR Coating (1064 nm)

    R > 99.8% @ 1064 nm

     

    Broad Band AR (OPO Range)

    R < 2% @ 1064–266 nm

  • Adhesion Test Compliant with MIL-C-675C military standards, an adhesion test involved applying a tape that meets LT-90 specifications onto the lens film layer. The tape was affixed fully and then removed vertically. This procedure was performed three times, resulting in no blistering or peeling.
  • Temperature Test In line with MIL-C-675C specifications, test pieces were subjected to temperatures of -62±1℃ and 71±1℃. After maintaining them at room temperature (16℃~32℃) for two hours, the adhesion test was repeated, confirming no film detachment.
  • Abrasion Resistance Test Conforming to MIL-C-675C and CCC-C-440 standards, the abrasion resistance test involved a gauze tester applying a minimum force of 1.0 lbs (0.45 kg) to the film. This was repeated 25 times with gauze widths of 1/4 inch (6.4mm) and 3/8 inch (9.5mm), ensuring no damage occurred to the film surface.
  • Humidity Test Under MIL-C-675C criteria, the test piece was placed in a controlled temperature and humidity chamber set to 49 ±2℃ and 95%~100% humidity for 24 hours. The film remained intact, with no peeling, scratches, or other defects.
  • Solvent and Cleaning Testing Following MIL-C-675C specifications, test pieces were exposed to room temperature conditions (16℃~32℃) and tested with acetone and alcohol for at least 10 minutes each. After air drying and subsequent cleaning with a cotton cloth soaked in alcohol, the film surface showed no signs of peeling or scratches.
  • Salt Spray Test After 100 hours in a 35°C environment with a 5% saltwater concentration, the film showed no signs of damage.

 

POC Strength and Capabilities

Photonics On Crystals specializes in high-quality GTR-KTP crystals with superior performance characteristics. Our strengths include:

  • Advanced manufacturing processes ensuring exceptional gray tracking resistance and optical properties.
  • Custom fabrication to meet exacting application requirements.
  • Extensive inventory with fast turnaround for standard and custom dimensions.
  • Competitive pricing and excellent technical support for optimal customer satisfaction.

Standard Products

Face Dimensions (mm)

Length (mm)

Coatings

Application

Price (USD)

3 × 3

5

AR@1064/532 nm

SHG of Nd:YAG lasers

350

5 × 5

10

HR@1064 nm

High-power laser systems

500

7 × 7

15

BBAR (OPO range)

OPO and parametric gain

750

Custom

Custom

Upon Request

Custom Applications

TBD