POC-OC-122434-Yb:KGW Crystal

  • High absorption coefficient at 981 nm and stimulated emission cross-section.
  • Extremely low quantum defect and broad polarized output (1023–1060 nm).
  • High slope efficiency with diode pumping.
  • Large gain bandwidth and small quantum defect.
  • Customizable Yb doping levels for diverse applications.

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

Yb:KGW Crystal Material General Description

Ytterbium-doped Potassium Gadolinium Tungstate (Yb:KGW) is a monoclinic crystal known for its broad emission bandwidth, making it suitable for ultrafast laser applications. It features high thermal conductivity, enabling efficient heat dissipation under intense laser pumping conditions. The unique structural properties of Yb:KGW allow operation with high doping concentrations, minimizing quantum defects. These characteristics ensure low lasing thresholds, high efficiency, and superior performance for femtosecond lasers, CW lasers, and regenerative amplifiers.

 

Yb:KGW Crystal General Applications and Examples

Yb:KGW crystals are widely used in:

  1. Femtosecond Lasers: Enable pulse durations below 100 fs, crucial for ultrafast spectroscopy and high-precision micromachining.
  2. CW Lasers and Mode-Locked Lasers: Deliver stable and efficient output for scientific and industrial applications.
  3. Thin-Disk Lasers: High gain bandwidth and excellent thermal conductivity make Yb:KGW Crystal ideal for thin-disk laser designs.
  4. Diode Laser Pumping: The broad absorption spectrum at 981 nm ensures compatibility with commercial laser diodes.
  5. Medical Applications: Provide high-powered outputs for advanced surgical techniques and diagnostics.

Chemical and Structural Properties

Property

Value

Crystal Structure

Monoclinic

Point Group

C2/c

Lattice Parameters (Å)

a = 8.09, b = 10.43, c = 7.588, β = 94.4°

Density

7.27 g/cm³

Melting Point

1075 °C

Mohs Hardness

5

Thermal Conductivity (W/m·K)

K_100 = 3.4, K_a = 2.6

Thermal Expansion Coefficients

a = 4 × 10^-6 K^-1, b = 8.5 × 10^-6 K^-1

Optical, Laser and Nonlinear Optical Properties

Parameter

Specification

Orientation

[010]

Standard Dopant Level

5 at.%

Maximum Length

50 mm

Dimensional Tolerances

Diameter: ±0.1 mm, Length: ±0.5 mm

Surface Quality (Scratch/Dig)

20/10

Surface Flatness

λ/6 @ 633 nm

Parallelism

20 arc sec

Perpendicularity

≤15 arc min

Standard Fabrication Specifications

Specification

Value

Dimension Tolerance

±0.1 mm (standard); ±0.005 mm (high precision)

Clear Aperture

Central 95% of the diameter

Surface Quality

20-10 Scratch-Dig

Surface Flatness

λ/8 at 633 nm

Parallelism

<10 arc seconds

Perpendicularity

<5 arc minutes

Chamfer

0.1 mm at 45°

Damage Threshold

>15 J/cm² (10 ns, 10 Hz at 1064 nm)

Spectrum Transmission Curve:

The absorption and emission spectra highlight the broad bandwidth at 981 nm and efficient emission around 1030 nm, suitable for femtosecond and thin-disk lasers.

Coating Specification:

 

  • AR coatings available for 1030/980 nm configurations.
  • Reflectance: R < 0.2% @ 1030 nm; R < 0.5% @ 980 nm.
  • Custom coating specifications can be provided upon request.
  • 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 (POC) excels in the production of high-quality Yb:KGW crystals tailored for advanced laser applications. Our state-of-the-art facilities ensure precise doping, superior surface quality, and reliable performance. POC supports customization to meet specific project requirements and guarantees prompt delivery with stringent quality control.

Standard Products

Face Dimensions

Length

End Faces

Doping

Coatings

Price (USD)

3 × 3 mm

10 mm

Brewster-angle cut

1%

Uncoated

$590

5 × 5 mm

5 mm

Right-angle cut

2%

AR 980/1030 nm

$640

3 × 3 mm

2 mm

Brewster-angle cut

3%

Uncoated

$590

5 × 5 mm

5 mm

Right-angle cut

5%

AR 980/1030 nm

$640

Custom Size

Custom

Any

Custom

Custom

Request