POC-OC-122441-Ho:Cr:Tm:YAG Crystal

  • High Slope Efficiency: Enhanced performance for efficient energy conversion.
  • Versatile Pumping Sources: Compatible with both flashlamp and diode pumping.
  • Stable at Room Temperature: Ensures reliable operation in various environments.
  • Eye-Safe Wavelength Range: Ideal for applications requiring safety standards.
  • Customizable Design: Available in various specifications tailored to user needs.

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

Ho:Cr:Tm:YAG Crystal Material General Description

The Ho:Cr:Tm:YAG Crystal (Holmium, Chromium, Thulium co-doped Yttrium Aluminum Garnet) crystal is a high-efficiency laser material emitting at a wavelength of 2.1 µm. This emission wavelength is particularly valuable for medical, atmospheric, and industrial applications due to its position in the eye-safe range and its compatibility with biological tissues.

The co-doping of Ho, Cr, and Tm ions enhances energy transfer, reduces the lasing threshold, and improves slope efficiency. The Cr ions act as sensitizers, absorbing pump energy efficiently and transferring it to the Tm ions, which subsequently transfer the energy to the Ho ions for final laser emission. This process ensures high efficiency and excellent thermal stability, making Ho:Cr:Tm:YAG a preferred material for CW and pulsed lasers.

With its ability to be pumped by flashlamps or diodes, combined with high optical quality and thermal conductivity, this crystal meets the demanding requirements of modern laser systems.

 

Ho:Cr:Tm:YAG Crystal General Applications and Examples

  1. Medical Applications:
    • Surgery and Dentistry: The 2.1 µm emission wavelength matches the absorption peak of water, making it ideal for precise tissue ablation and cutting in minimally invasive surgeries.
    • Ophthalmology: Ho:Cr:Tm:YAG Crystal Suitable for eye-safe laser procedures.
    • Dermatology: Used for non-invasive skin treatments.
  2. Industrial Applications:
    • Material Processing: High-energy lasers for cutting and engraving materials requiring minimal thermal distortion.
    • Precision Machining: Ideal for drilling and marking heat-sensitive components.
  3. Scientific Applications:
    • Atmospheric Testing: Utilized in LIDAR systems for remote sensing and environmental monitoring.
    • Spectroscopy: Suitable for molecular analysis and gas detection.
  4. Military and Defense Applications:
    • Laser Rangefinding: Eye-safe lasers for accurate distance measurement.
    • Target Designation: Infrared lasers compatible with advanced targeting systems.
    • Remote Sensing: Applications in detecting and monitoring atmospheric conditions.
  5. Custom Solutions:
    • Ho:Cr:Tm:YAG Crystal Ideal for tailored laser systems requiring eye-safe emissions with high energy efficiency and precise control.

Chemical and Structural Properties

Property

Specification

Crystal Structure

Cubic Garnet

Chemical Formula

Ho:Cr:Tm:Y3Al5O12

Growth Method

Czochralski

Density

4.56 g/cm³

Dopant Concentration

Ho: 0.35 at.%, Cr: 1.5 at.%, Tm: 5.8 at.%

Refractive Index

1.80 @ 2.08 µm

Thermal Conductivity

12 W/m/K

Thermal Expansion Coefficient

7.8 × 10^-6 K⁻¹

Hardness

8.5 Mohs

Optical Homogeneity

< λ/10

Melting Point

1970 °C

Optical, Laser and Nonlinear Optical Properties

Parameter

Specification

Laser Transition

^5I7 → ^5I8

Laser Wavelength

2.097 µm

Photon Energy

9.55 × 10^-20 J

Emission Cross Section

7 × 10^-20 cm²

Fluorescence Lifetime

8.5 ms

Absorption Linewidth

4 nm

Diode Pump Band

781 nm

Major Pump Bands

400–800 nm

Mode of Operation

CW, Pulsed

Standard Fabrication Specifications

Specification

Value

Rod Dimensions

Diameter: 3–6 mm, Length: 50–120 mm

Surface Quality

10/5 scratch-dig per MIL-PRF-13830B

Flatness

A/8 @ 633 nm

Parallelism

<30 arc sec

Perpendicularity

<15 arc min

Chamfer

0.2 mm × 45°

Mounting

Unmounted

Spectrum Transmission Curve:

Ho:Cr:Tm:YAG exhibits strong absorption at 781 nm for efficient pumping and high emission at 2.1 µm, ensuring optimal energy transfer and emission stability. The crystal supports eye-safe laser operation with minimal thermal distortion.

Coating Specification:

 

  • Standard Coating:
    • AR-coated for 781 nm (pump wavelength) and 2.1 µm (emission wavelength).
    • Reflectivity < 0.2% per surface.
  • Custom Coating:
    • Available upon request, tailored to specific applications.
  • 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) is a trusted manufacturer of high-performance laser crystals like Ho:Cr:Tm:YAG. Leveraging state-of-the-art crystal growth and rigorous quality control processes, POC ensures exceptional product performance and reliability. Our ability to customize designs for specific applications demonstrates our commitment to excellence and customer satisfaction.

Standard Products

Dimensions

Length

End Faces

Doping

Coating

Price (USD)

3 × 3 mm

10 mm

Brewster-angle cut

Ho: 0.35%, Cr: 1.5%, Tm: 5.8%

AR-coated @ 2.1 µm

$720

5 × 5 mm

20 mm

Right-angle cut

Ho: 0.35%, Cr: 1.5%, Tm: 5.8%

AR-coated @ 2.1 µm

$850

10 × 10 mm

50 mm

Brewster-angle cut

Ho: 0.35%, Cr: 1.5%, Tm: 5.8%

Custom Coating

$1050

Customization

As needed

As needed

As requested

As requested

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