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AgGaS2 Crystal

POC-OC-122424-AgGaS2 Crystal

  1. Wide Transparency Range: Operates effectively between 0.5 µm and 13.2 µm, suitable for mid-infrared and far-infrared applications.
  2. High Nonlinear Optical Coefficients: Supports SHG, OPO, and DFG processes with efficiency.
  3. Low Optical Absorption and Scattering: Optimized for minimal energy loss during operation.
  4. High Damage Threshold: Suitable for high-power lasers, with damage thresholds >10 MW/cm².
  5. Versatile Coatings Available: Broadband AR coatings enhance performance in specific wavelength ranges.

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

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General Description

Silver Thiogallate (AgGaS₂) is a nonlinear optical crystal widely used in mid-infrared laser applications due to its broad transparency range of 0.5–13.2 µm. It exhibits high nonlinear optical coefficients and low optical absorption, making it ideal for frequency conversion processes such as second-harmonic generation (SHG), optical parametric oscillation (OPO), and difference frequency generation (DFG).

The crystal is particularly suited for CO₂ laser systems and Nd:YAG lasers, enabling mid-IR output in the range of 3–12 µm. Its high damage threshold and efficient thermal conductivity ensure stable operation in high-power and continuous-wave systems. AgGaS₂ is commonly used in laser spectroscopy, environmental sensing, and medical applications

General Applications and Examples

AgGaS₂ crystals are versatile and widely used in nonlinear optical applications. Below are some key examples:

  1. Second-Harmonic Generation (SHG):
  • AgGaS2 Crystal  Efficiently converts infrared wavelengths into shorter visible or near-infrared outputs.
  • Example: Used in CO₂ lasers for generating 10.6 µm SHG light.
  1. Optical Parametric Oscillators (OPO):
  • Tunable output wavelengths in the 3–12 µm range for mid-IR laser systems.
  • Example: AgGaS₂-based OPOs are applied in environmental gas sensing and spectroscopy.
  1. Difference Frequency Generation (DFG):
  • AgGaS2 Crystal  Combines two high-frequency inputs to produce mid-infrared wavelengths.
  • Example: Ideal for generating mid-IR lasers used in industrial and scientific applications.
  1. Tunable Laser Systems:
  • Enables frequency mixing and wavelength tuning in Nd:YAG laser systems.
  • Example: Used for high-precision spectroscopy and medical laser applications.
  1. Infrared Spectroscopy:
  • AgGaS2 Crystal  Provides mid-IR light sources for material characterization and biomedical research.
  • Example: Used in advanced spectroscopy setups to identify chemical compositions.

Chemical and Structural Properties

PropertyValue
Chemical FormulaAgGaS₂
Crystal StructureTetragonal, 42m
Lattice Parametersa = 5.742 Å, c = 10.26 Å
Density4.7 g/cm³
Mohs Hardness3.35
Melting Point997 °C
Transparency Range0.5 µm–13.2 µm
Nonlinear Coefficientsd_eff = 12.5 pm/V at 10.6 µm
Thermal Conductivity1.4 W/m·K
Refractive Indices (10.6 µm)nₒ = 2.3471, nₑ = 2.2916

Optical and Nonlinear Optical Properties

PropertyValue
Nonlinear ProcessSHG, DFG, OPO
Refractive Indicesnₒ = 2.3471, nₑ = 2.2916 at 10.6 µm
Absorption Coefficient<0.05 cm⁻¹ at 1.064 µm; <0.02 cm⁻¹ at 10.6 µm
Damage Threshold>10 MW/cm² (150 ns pulses at 10.6 µm)
Sellmeier Equationsn² = 5.79419 + 0.23116/(λ² – 0.06882) – 2.4534λ
 n² = 5.54120 + 0.22041/(λ² – 0.09824) – 2.5240λ

Standard Fabrication Specifications

SpecificationValue
Dimensions5 × 5 × 1 mm (standard)
Surface FlatnessLambda/6 @ 632.8 nm
Parallelism< 30 arc seconds
Perpendicularity< 10 arc minutes
Surface Quality60-40 Scratch-Dig

Spectrum Transmission Curve

The transmission curve of AgGaS₂ shows high transparency across its operating range of 0.5–13.2 µm.

Key characteristics include:

  • Peak Transmission: 0.6–12 µm.
  • Absorption Points: Slightly reduced transmission at lower and higher wavelength boundaries.

(Note: Graphical representations can be provided upon request from POC’s technical team.)

POC-AgGaS2 Crystal Spectrum Transmission Curve

Coating Specification

  • Broadband AR Coating: BBAR at 1.2–2.6 µm and 2.6–11 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.
Product Code Dimensions (mm) Coating Price (USD)
AGGS-01 5 × 5 × 1 BBAR @ 1.2–2.6 µm Request Quote
AGGS-02 8 × 8 × 1 BBAR @ 2.6–11 µm Request Quote
AGGS-03 10 × 10 × 2 Customizable Request Quote
Custom-AGGS Customizable Customizable Request Quote

POC-OC-122424-AgGaS2 Crystal

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