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BaGa4S7 Crystal

POC-OC-122420-BaGa4S7 Crystal

  • Wide transparency range: 0.35–13.7 μm.
  • High nonlinear optical coefficient: d33 = 12.7 pm/V.
  • Excellent chemical stability and low optical absorption.
  • High damage threshold for intense laser applications.
  • Ideal for frequency conversion processes like OPA, DFG, and SFG.

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

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General Description

BaGa4S7 Crystal, also known as BGS Crystal, is a transparent pale-yellow crystal with exceptional nonlinear optical (NLO) properties. This crystal is distinguished by its broad transparency range from 0.35 μm to 13.7 μm, a wide bandgap of 3.54 eV, and a high damage threshold. BaGa4S7 is chemically stable and exhibits a high nonlinear optical coefficient of d33 = 12.7 pm/V.

Uniquely, BaGa4S7 has minimal two-photon absorption at 1 μm, making it highly efficient for 1064 nm Nd:YAG laser pumping. This crystal is widely used in nonlinear frequency conversion processes, including optical parametric oscillation (OPO) and second-harmonic generation (SHG). Additionally, it is compatible with widely available 1030 fs lasers for advanced photonics applications.

General Applications and Examples

BaGa4S7 Crystals are highly versatile and find applications in a wide range of industries. Some key examples include:

  1. Laser Frequency Conversion: BaGa4S7 is highly suitable for generating mid-IR wavelengths through frequency conversion processes such as OPA, DFG, and SFG, providing efficient laser wavelength tuning.
  2. Nd:YAG Laser Pumping: The crystal is an excellent medium for 1064 nm Nd:YAG laser pumping, enabling efficient parametric oscillation and higher-order harmonic generation.
  3. Biomedical Applications: With its high optical clarity and low absorption losses, BaGa4S7 supports biomedical imaging and diagnostics in the mid-IR region.
  4. Spectroscopy: BaGa4S7 Crystals are used for advanced spectroscopic studies, especially in atmospheric sensing and material characterization.
  5. Defense and Lidar: The crystal’s broad transparency range and high damage threshold make it ideal for lidar technologies and defense applications in high-power laser systems.

Chemical and Structural Properties

PropertyValue
Transparency Range0.35–13.7 μm
Nonlinear Coefficientd33 = 12.7 pm/V
Density3.95 g/cm³
Surface Quality (Scratch/Dig)40-20
Bandgap Energy3.54 eV
Melting Point1000°C

Optical and Nonlinear Optical Properties

PropertyValue
Transparency Range0.35–13.7 μm
Nonlinear Coefficientd33 = 12.7 pm/V
Laser Damage ThresholdHigh
Surface Quality40-20

Standard Fabrication Specifications

SpecificationValue
Dimension Tolerance±0.1 mm
Surface Quality (Scratch/Dig)40-20
Flatnessλ/8 @ 632.8 nm
Parallelism<30 arc sec
Perpendicularity<10 arc min
Edge Bevel<0.2 mm × 45°

Spectrum Transmission Curve

Spectrum transmission curves can be provided upon request, showcasing superior transparency in the range of 0.35–13.7 μm

Coating Specification

  • AR Coatings: Anti-reflective coatings optimized for the 0.8–1.2 μm and 3–5 μm ranges.
  • Dual-Band Coatings: Customized for specific mid-IR laser wavelengths.
  • Customization: Available for high-power applications 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.
Face Dimensions (mm)Length (mm)Orientation (Theta/Phi)CoatingApplicationPrice (USD)
5 × 5100°/0°AR @ 3–5 μmMid-IR spectroscopyRequest
10 × 10150°/0°AR @ 8–12 μmFrequency conversionRequest
CustomCustomCustomCustomCustomRequest

POC-OC-122420-BaGa4S7 Crystal

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