ECCN 6C004

NSAT

Optical materials as follows .

Category: 6 - Sensors & LasersProduct Group: C - MaterialsLast Updated: 2026-04-10

What This ECCN Covers

ECCN 6C004 controls specified optical materials — for example large-volume zinc selenide (ZnSe) and zinc sulfide (ZnS), and certain other infrared and high-performance optical substrate materials meeting the criteria in the entry. These materials are used in high-energy laser and infrared optics, and are controlled for National Security and Anti-Terrorism reasons.

Who needs to check this?

Suppliers of IR optical materials and blanks (ZnSe, ZnS, and similar), and optics manufacturers sourcing large or high-purity optical substrates.

Compliance tip

Control turns on the material type and dimensions/volume specified in the entry — confirm your blank against those thresholds, since smaller or different materials may fall outside. Check the NS and AT Country Chart columns before relying on a license exception.

Reviewed by Jack Tan · Last reviewed: Jun 4, 2026

Items Covered

  • 1. A volume greater than 100 cm3; or
  • 2. A diameter greater than 80 mm and a thickness of 20 mm or more;
  • b.Electro-optic materials and non-linear materials, as follows:
  • 1. Potassium titanyl arsenate (KTA) (CAS 59400-80-5);
  • 2. Silver gallium selenide (AgGaSe2, also known as AGSE) (CAS 12002-67-4);
  • 3. Thallium arsenic selenide (Tl3AsSe3, also known as TAS) (CAS 16142-89-5);
  • 4. Zinc germanium phosphide (ZnGeP2, also known as ZGP, zinc germanium biphosphide or zinc germanium diphosphide); or
  • 5. Gallium selenide (GaSe) (CAS 12024-11-2);
  • c.Non-linear optical materials, other than those specified by 6C004.b, having any of the following:
  • 1. Having all of the following:
  • 1.a. Dynamic (also known as nonstationary) third order nonlinear susceptibility (χ(3), chi 3) of 10−6 m2/V2 or more; and
  • 1.b. Response time of less than 1 ms; or
  • 2. Second order nonlinear susceptibility (χ(2), chi 2) of 3.3 × 10−11 m/V or more;
  • d."Substrate blanks" of silicon carbide or beryllium beryllium (Be/Be) deposited materials, exceeding 300 mm in diameter or major axis length;
  • e.Glass, including fused silica, phosphate glass, fluorophosphate glass, zirconium fluoride (ZrF4) (CAS 7783-64-4) and hafnium fluoride (HfF4) (CAS 13709-52-9) and having all of the following:
  • 1. A hydroxyl ion (OH-) concentration of less than 5 ppm;
  • 2. Integrated metallic purity levels of less than 1 ppm; and
  • 3. High homogeneity (index of refraction variance) less than 5 × 10−6;
  • f.Synthetically produced diamond material with an absorption of less than 10−5 cm−1 for wavelengths exceeding 200 nm but not exceeding 14,000 nm.

Control Reasons

NSNational Security

Items controlled for national security reasons under multilateral export control regimes.

Column 1: YesColumn 2: No
ATAnti-Terrorism

Items controlled for anti-terrorism reasons. Most items on the CCL have AT controls.

Column 1: YesColumn 2: No

Disclaimer

This information is for reference only. For official classifications, consult BIS or a qualified export control professional.

Official Reference

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