Specialty HEM Sapphire Products

Specialty HEM Sapphire Products

Specialty HEM Sapphire Products

Overview

GT's advanced sapphire material is recognized as the highest commercial quality sapphire available with excellent optical, mechanical and transmission properties. Our advanced sapphire production capabilities give our customers the quality and flexibility they need to meet material requirements for the most demanding applications.
 
The combination of high purity level, crystalline perfection, and low light scatter give our customers an advantage in their applications. Learn more about our specialty materials used for the most extreme and demanding applications.

  • Hemex Sapphire - is world renowned for showing no stress birefringence, no bubbles and no other defects

  • HEM (LAOS) - Low Absorption Optical Sapphire - used in applications where minimal photon absorption is critical.

  • HEM (LAOS 193) - Vacuum Ultra Violet Sapphire - special sapphire product optimized for UV and VUV applications.
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    Hemex Sapphire  

    Transmitted Wavefront HEMEX Window

    Transmitted Wavefront HEMEX Window

    GT's advanced sapphire material group, GT Crystal Systems, produces the world’s highest quality sapphire called Hemex Sapphire.  This special sapphire has perfect crystalline structure with no detectable light scatter and is capable of supporting finished optics with transmitted wave front values of 1/20 wave peak to valley and better.  Hemex material has been independently characterized using Berg-Barrett X-Ray topography which concluded that no dislocations in the crystalline structure could be found.  These superior crystals are utilized in applications where no compromises can be made; Hemex is the absolute pinnacle of sapphire quality.  

    Attributes and Features

    Hemex material is world renowned for showing no stress birefringence, no bubbles and no other defects.
    • Ultra-low dislocation density
    • Homogeneity of refractive index as low as 0.022 PV (peak to valley) waves
    • No detectable light scatter or inclusions
    • Supports optics of 1/20 wave and better 
     

    Applications

    Hemex is used in critical engineering applications where zero defect sapphire is needed to support the fabrication of sophisticated optical components and systems.  These applications can include high power laser optics, acoustic wave devices, 1/10 wave optics and neutron filters.

     

    HEM (LAOS) Low Absorption Optical Sapphire

    GT’s Low Absorption Optical Sapphire (LAOS) is used in applications where minimal photon absorption is critical.  The material is ultra high-purity and is processed in specialized conditions in order to avoid absorption bands.  LAOS material can be optimized for the precise application wavelength, for instance 1064nm, which is a common high power laser wave length.  Photothermal Common-path Interferometry has shown LAOS sapphire to have as little absorption as 41ppm/cm at 1064nm.  LAOS material can be developed specifically for the wavelengths of your system.

    Attributes and Features

    • Low absorption optimized for your wavelength
    • Absorption as low as 41ppm/cm @ 1064
    • Ultra high purity
    • High power laser window material

    Applications

    LAOS is used for high power laser windows where photon absorption cannot be tolerated.  If unwanted photons are absorbed by the intrinsic optical material thermal gradients will result, which can cause thermal lensing or catastrophic failure of the optical element.  LAOS is ideally suited for situations where every photon counts.  LAOS is available on special request according to the design of your optic and its spectral operating range.

     

    HEM LAOS 193 Sapphire

    LAOS 193 (vacuum ultra violet) grade of sapphire is a special sapphire product optimized for UV and VUV applications where transmission is improved below 260 nm.  HEM VUV (vacuum ultra violet) grade of sapphire combines high purity with extremely low defect density and special processing steps; the resulting material transmits light at the 205 nm range where standard sapphire material absorbs the light. The VUV grade of sapphire is especially resistant to solarization and damage from radiation and the effects of long term immersion in high power UV light.  

    Specialty Comparison Transmission of Standard vs. VUV

    Transmission Curve of LAOS 193 Window

    Attributes and Features

    • Maximized transmission below 260nm
    • UV and VUV optimized
    • Ultra high purity
    • Solarization resistant

     

    Applications

    HEM VUV material is optimized for use under 260nm.  The optical community is finding new opportunities to leverage sapphire’s mechanical strength at wave lengths previously unsuited for sapphire.  HEM VUV material is now available for use in the vacuum and vacuum ultra violet spectral regions.  This material excels in applications such as Raman Spectroscopy, white light generation, 193nm lithography and for use as laser optics.

     

    Please contact sapphiresales@gtat.com or call +1.978.745.0088 with any questions.

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