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AgGaSe2 Crystal

POC-OC-122425-AgGaSe2 Crystal

  1. Broad Transmission Range: Operates from 0.73 µm to 18.3 µm, ideal for mid-IR and far-IR applications.
  2. High Nonlinear Coefficient: Efficient for SHG, DFG, OPO, and other nonlinear optical processes with d_eff = 33 pm/V at 10.6 µm.
  3. Low Absorption and High Transparency: Excellent performance with low absorption at key wavelengths.
  4. High Thermal and Damage Threshold: Withstands high laser intensities with >10 MW/cm² damage threshold at 10.6 µm.
  5. Versatile Applications: Suitable for CO₂ lasers, solid-state lasers, and tunable OPO systems.

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

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Material General Description of AgGaSe2 Crystal

Silver Gallium Selenide (AgGaSe₂) is a nonlinear optical crystal with a wide transparency range of 0.73–18.3 µm, making it indispensable for mid-infrared and far-infrared optical systems. Known for its exceptional nonlinear optical coefficients (d_eff = 33 pm/V at 10.6 µm), AgGaSe₂ is commonly used in frequency conversion processes, including second-harmonic generation (SHG), optical parametric oscillation (OPO), and difference frequency generation (DFG).

With low absorption, high damage thresholds, and precise phase-matching capabilities, AgGaSe₂ is a critical component for CO₂ lasers, tunable laser sources, and infrared spectroscopy systems. Its Sellmeier equations ensure accurate refractive index calculations, allowing efficient design of nonlinear optical systems.

 

General Applications and Examples of  AgGaSe2 Crystal

AgGaSe₂ crystals are versatile and widely used in high-performance nonlinear optical systems. Below are some of the key applications:

  1. Frequency Conversion:
  • Efficient SHG, DFG, and SFG processes for IR and mid-IR wavelengths.
  • Example: Used for generating mid-IR wavelengths from CO and CO₂ laser systems in industrial and scientific research.
  1. Optical Parametric Oscillators (OPOs):
  • AgGaSe2 Crystal Enables tunable wavelength generation from 4.0 to 18.3 µm.
  • Example: AgGaSe₂-based OPOs are applied in environmental gas sensing and medical diagnostics.
  1. Mid-IR Lasers:
  • AgGaSe2 Crystal Enhances the functionality of CO₂ and CO lasers for high-precision cutting, engraving, and spectroscopy.
  • Example: Used in industrial laser systems for cutting and material processing.
  1. Spectroscopy and Sensing:
  • Facilitates mid-IR spectroscopy for material and biomedical analysis.
  • Example: Ideal for infrared imaging and detection systems in research labs.
  1. Quantum Optics:
  • Supports advanced quantum systems requiring mid-IR photon generation and manipulation.
  • Example:  AgGaSe2 CrystalUsed in secure quantum communication systems and IR photon detectors.

Chemical and Structural Properties

Property

Value

Chemical Formula

AgGaSe₂

Crystal Structure

Tetragonal, 42m

Lattice Parameters

a = 5.992 Å, c = 10.8803 Å

Density

5.7 g/cm³

Mohs Hardness

3.35

Melting Point

851 °C

Transparency Range

0.73 µm–18.3 µm

Nonlinear Coefficients

d_eff = 33 pm/V at 10.6 µm

Thermal Conductivity

1.4 W/m·K

Thermal Expansion Coefficient

19.8 × 10⁻⁶/°C

Optical and Nonlinear Optical Properties

Property

Value

Nonlinear Process

SHG, DFG, SFG, and OPO

Refractive Indices (10.6 µm)

nₒ = 2.5917, nₑ = 2.5585

Absorption Coefficient

<0.05 cm⁻¹ at 1.064 µm; <0.02 cm⁻¹ at 10.6 µm

Laser Damage Threshold

>10 MW/cm² (150 ns pulses at 10.6 µm)

Sellmeier Equations

n² = 6.6792 + 0.4598/(λ² – 0.2122) – 0.00126λ²

 

n² = 6.8507 + 0.4297/(λ² – 0.1584) – 0.00125λ²

Standard Fabrication Specifications

Specification

Value

Dimensions

5 × 5 × 1 mm (standard)

Surface Flatness

Lambda/6 @ 632.8 nm

Parallelism

< 30 arc seconds

Perpendicularity

< 10 arc minutes

Surface Quality

60-40 Scratch-Dig

Spectrum Transmission Curve:

The spectrum transmission range of AgGaSe₂ is characterized by high transparency between 0.73 and 18.3 µm. The crystal shows minimal losses across this range, making it suitable for mid-IR and far-IR applications. Key characteristics:

  • Peak Transmission: Between 3 µm and 12 µm.
  • Lower Transparency: Slight absorption below 0.73 µm and above 18 µm.

(Note: Graphical data can be generated or requested from POC’s technical team.)

Coating Specification:

Coating Type

Specifications

Broadband AR Coating

BBAR at 1.7–2.7 µm and 5–18 µm

Custom Coatings

Available 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) is a premier supplier of high-quality nonlinear optical crystals. With state-of-the-art manufacturing facilities, POC provides:

    • Customizable solutions tailored to specific applications in spectroscopy, lasers, and sensing.
    • Expertise in optical coatings and precision crystal engineering.
    • Global technical support and rapid prototyping for research and industry.

Standard Products

Product Code

Dimensions (mm)

Coating

Price (USD)

AGSE-01

2 × 2 × 1

BBAR @ 1.7–2.7 µm

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AGSE-02

5 × 5 × 1

BBAR @ 5–18 µm

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AGSE-03

10 × 10 × 2

BBAR @ 1.7–18 µm

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Custom-AGSE

Customizable

Customizable

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POC-OC-122425-AgGaSe2 Crystal

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