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Silicon Crystal

POC-OC-122477-Silicon Crystal

  • Excellent light transmission properties in the 1-7 μm band, ideal for infrared applications.
  • Transparent in the far infrared spectrum from 30-300 μm, rare in other optical materials.
  • High thermal conductivity and low density, perfect for laser mirror substrates.
  • Durable single-crystal structure with low absorption rates.
  • Ideal for 3-5 μm mid-wave infrared optical windows and filters.

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

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General Description

Silicon single crystal is a highly durable material known for its excellent optical transmission in the infrared spectrum, spanning from 1 to 7 μm. Its unique property of transparency in the far-infrared range (30-300 μm) makes it an ideal choice for specialized optical components. The material is commonly used in mid-wave infrared (MWIR) optical systems due to its outstanding transmission and minimal absorption. The crystalline structure is strong and insoluble in water, ensuring stability and robustness for demanding applications. Thanks to its high thermal conductivity and low density, silicon crystals are also utilized in laser mirror substrates and filters.

General Applications and Examples

Silicon crystals find extensive applications across diverse scientific and industrial fields due to their exceptional optical and thermal properties:

  1. Infrared Optics
    Silicon crystals are commonly used in infrared optical systems for their transmission capabilities in the 1-7 μm range. These systems include infrared imaging, thermal imaging cameras, and spectroscopic instruments.
  2. Mid-Wave Infrared (MWIR) Windows and Lenses
    Silicon’s low absorption and high transmission in the 3-5 μm range make it ideal for MWIR optical windows and lenses used in defense, aerospace, and industrial applications.
  3. Laser Mirror Substrates
    With high thermal conductivity and low density, silicon crystals are optimal for manufacturing substrates in laser mirrors, especially in high-power laser systems.
  4. Optical Filters
    The material is often employed in optical filters for specific infrared wavelengths due to its precise transmission range and stability.
  5. Semiconductor Applications
    Besides optical uses, silicon crystals are integral to the semiconductor industry, serving as a base material for microelectronic components.

Chemical and Structural Properties

PropertySpecification
Material GradeCZ, FZ; Intrinsic Silicon
Max Crystal SizeØ300 mm
Growing MethodCZ/FZ
Crystal StructureMonocrystalline
TypeN-type/P-type
Cleavage Planes<111>
Density2.33 g/cm³
Thermal Conductivity148 W/m·K
Thermal Expansion2.6 × 10^-6 /K
Mohs Hardness7
Melting Point1,410°C
Specific Heat Capacity700 J/kg·K

Optical Properties

Optical PropertySpecification
Transmittance Range1.2-15 μm
Transmittance>95% in the 1-6 μm range
Refractive Index3.42 (at 1.5 μm)
Absorption Coefficient10^-3 @10.6 μm
Thermal Lens EffectsNegligible for standard power
Laser Damage Threshold>10 J/cm² @1064 nm, 10 ns

Standard Fabrication Specifications

SpecificationDetails
Flatnessλ/8 @632.8 nm
Parallelism<1 arcmin
Surface Quality40-20 (scratch-dig)
Clear Aperture>90%
Bevel<0.25 mm × 45°
Length Tolerance±0.1 mm
Coating OptionsCustomizable as per user request

Spectrum Transmission Curve

Two transmission curves are provided:

  1. CZ Silicon Transmission Curve: Highlights transparency in the 1-15 μm range with minimal loss.
  2. FZ Silicon Transmission Curve: Demonstrates high transmission in the far-infrared spectrum, up to 300 μm.
POC-Silicon Crystal Spectrum Transmission Curves

Coating Specification

Coating TypeWavelength RangeReflection LossDurability
Standard AR Coating1-7 μm<0.5%Scratch-resistant
Custom CoatingOn demand<0.3%High durability
  • 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.
ProductDimensionsCoatingPrice (USD)
Silicon WindowØ100 mmAR (1-7 μm)300
Silicon LensØ50 mmAR (3-5 μm)150
Custom Silicon PartsOn requestCustom CoatingBased on spec.

POC-OC-122477-Silicon Crystal

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