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Er:KYW Crystal

POC-OC-122463-Er:KYW Crystal

  • Strong absorption bandwidth near 1534 nm, ideal for InGaAsP/InP laser diode emission.
  • Wide emission bandwidth near 1600 nm for high versatility.
  • High energy conversion efficiency with low quantum defect (>80% slope efficiency).
  • Enables “eye-safe” laser operations in CW and Q-switched modes.
  • Custom crystal sizes and orientations available upon request.

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

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Er:KYW Crystal Material General Description

Er:KYW (Erbium-doped Potassium Yttrium Tungstate) crystals are a promising active laser medium for “eye-safe” wavelength emissions, particularly in the 1570-1630 nm spectral range. These crystals are tailored for diode-pumped solid-state lasers, benefiting from their broad absorption and emission bands. Their high efficiency in energy transfer, coupled with excellent thermo-mechanical properties, makes them suitable for high-power and pulsed laser systems. Er:KYW crystals exhibit a low quantum defect, allowing superior slope efficiencies when pumped by InGaAs/InP diode lasers. The broad emission spectrum also supports the generation of mode-locked laser pulses.

 

Er:KYW Crystal General Applications and Examples

Er:KYW crystals find applications across a wide range of laser systems, including:

  1. In-Band Pumped “Eye-Safe” Lasers: With emissions in the 1530-1600 nm range, these lasers are ideal for applications where eye safety is a critical concern, such as:
    • Medical diagnostics and therapeutic procedures.
    • Environmental monitoring and industrial process control.
  2. Waveguide Lasers: Their wide absorption and emission capabilities allow efficient integration into waveguide lasers, providing compact and efficient designs.
  3. Diode-Pumped Solid-State Lasers: Er:KYW crystals can be resonantly pumped using fiber or diode lasers, achieving high slope efficiencies for CW and Q-switched operations.
  4. Mode-Locked Lasers: The broad and smooth emission spectra support the generation of ultra-short laser pulses for femtosecond applications.

Chemical and Structural Properties

Property

Value

Chemical Formula

Er:KY(WO₄)₂

Absorption Peak Wavelength

1534 nm

Emission Wavelength

1609 nm

Absorption Bandwidth (at peak)

3 nm

Emission Cross-Section

0.4 × 10^-20 cm²

Lifetime of Er³⁺ Upper Laser Level

3.1 ms

Refractive Index

n_p = 2.05, n_m = 2.01, n_g = 1.97

Crystal Structure

Monoclinic

Density

6.5 g/cm³

Mohs Hardness

5

Thermal Conductivity

3.5 W/m·K

Typical Doping Level

<20 at.%

Optical, Laser and Nonlinear Optical Properties

Optical Property

Value

Absorption Coefficient at Peak

2.4 × 10^-20 cm²

Absorption Wavelength Range

1520-1540 nm

Emission Cross-Section

0.4 × 10^-20 cm²

Emission Bandwidth

3 nm

Laser Wavelength

1570-1630 nm

Efficiency

>80% (High slope efficiency)

Transparency Range

400 nm to 5 μm

Standard Fabrication Specifications

Specification

Value

Orientation

N_p-cut (standard), other cuts available

Clear Aperture

>90%

Face Dimensions Tolerance

+0/-0.1 mm

Length Tolerance

±0.1 mm

Parallelism Error

<20 arcsec

Perpendicularity Error

<10 arcmin

Surface Flatness

<λ/10 @ 632.8 nm

Surface Quality

20-10 S-D

Laser Damage Threshold

>10 J/cm² @1530 nm, 10 ns

Mount

Unmounted

Spectrum Transmission Curve:

The absorption and emission spectra indicate strong absorption at 1534 nm and significant emission near 1609 nm. This aligns well with the emission wavelengths of InGaAs/InP diode lasers, making Er:KYW ideal for these systems.

Coating Specification:

 

  • AR Coating: Custom coatings available for optimized transmission between 1520-1640 nm.
  • Standard Coatings:
    • AR/AR@1530-1600 nm for both crystal faces.
    • Reflectance <0.25% at specified wavelength ranges.
  • 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) specializes in precision fabrication of high-quality laser crystals tailored for cutting-edge applications. Our expertise includes:

  • Custom orientation, doping, and dimensions.
  • Advanced AR/HR coating capabilities.
  • Strict quality control ensuring surface flatness and damage threshold adherence.
  • Quick delivery times with excellent customer support for customized solutions.

Standard Products

Face Dimensions (mm)

Length (mm)

Coating

Price (USD)

3 × 3

5

AR/AR@1530-1600 nm

Request

3 × 3

10

AR/AR@1530-1600 nm

Request

Customization

Available

Upon Request

Request

POC-OC-122463-Er KYW Crystal

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