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SAPPHIRE

  • INFO
  • Properties
  • Applications
  • We offer

     
     

    INFO:                                                                                                                       back

    Single crystal sapphire (Al2O3) is one of the most durable materials with wide transmission range from 150nm to 6 microns..
    The main advantages of using sapphire in optical applications are it's hardness (the hardest of the oxide crystals) and extreme resistance where particle and acid contact are considerations, because it is chemically inert to common acids and alkali at temperatures up to 1000 °C as well as to HF below 300 °C
    Sapphire is scratch resistant to most materials and has in addition a high thermal conductivity, particularly at cryogenic temperatures
    Therefore it provides rapid heating and cooling capability.

    Possessing a unique combination of excellent optical, physical and chemical properties, Sapphire is an extraordinary material with a very wide application range.


     

     

     

    Properties of synthetic single-crystal sapphire:                                                        back

     

    Chemical Formula

    Al2O3

    Crystal structure

    hexagonal-rhomboedric

    Molecular Weight

    101.94

    Density, g/cm3 (20 °C)

    3.98

    Reflection Loss, % for two surfaces at 4 µm

    12

    Dielectric Constant for 102-108 Hz at 298 K
    parallel
    perpendicular


    10.55
    8.6

    Melting Temperature, K

    2300

    Thermal Conductivity, W/(m K) at 300 K
    parallel
    perpendicular


    35.1
    33.0

    Thermal Expansion, 1/K at 293 K
    parallel
    perpendicular


    5.6 x 10-6
    5.0 x 10-6

    Specific Heat, cal/(g K) at 298 K

    0.18

    Bandgap, eV

    9.9

    Solubility in water

    None

    Mohs Hardness

    9

    Knoop Hardness, kg/mm2

    1370

    Young's Modulus, GPa

    335

    Shear Modulus, GPa

    148

    Bulk Modulus, GPa at 273 K

    240

    Rupture Modulus, MPa

    350…690

    Poisson's Ratio

    0.25

     

    Transmission (through 0.8 mm thk sample)

     

    s

    Refractive Index for the Ordinary Ray

    Wavelength, µm

    0.30

    0.40

    0.70

    1.0

    2.0

    3.0

    4.0

    5.0

    Refractive Index

    1.814

    1.785

    1.763

    1.757

    1.740

    1.713

    1.667

    1.623

     

     

    Applications                                                                                                             back

    We process and polish Sapphire for following applications:

    · Spectroscopy
    · Vacuum Windows
    · Endoscopes and Boroscopes
    · Biomedical and Medical Instrumentation
    · Broadband UV to IR Systems
    · Lamp Windows
    · High Temperature Applications
    · Applications Requiring Scratch Resistance
    · Glasses for Luxury Clocks
    · Blue LEDs (e.g. Traffic Lights and Lamps)
    · Optical Components (e.g. Lenses, Windows, etc.)
    · Construction Elements for Ovens.
    · Protection for Thermo Elements.
    · Pressure Sensors
    · Components for  Laser technology
    · Substrates for Microelectronic Applications (e.g. SOS Technology)
    · Medical Instruments
    · Implantates

    And everywhere else where durability, inertness, thermical and chemical resistance are demanded!

     

     

    We offer:                                                                                                                 back

     

    Sapphire-Material:  Synthetical, optical Quality (mod. Czochralski), or special growth in dependence on application  (UV / visual / IR)

     

    Shapes:

    · Semi-finished products: as grown  (e.g. boules, plates, etc.)
                            ground cylinders
                            fine-ground Blanks
                            tolerances ±0,1 mm / ±0,05 mm

    · Any orientation deliverable , even with tolerances of axial-deviation ± 0.1°

    · Growing of sapphire-boules up to 250mm(!) diameter

    · On demand best sapphire-crystals, optical quality, almost scatter-free

    · Rondelles up to 240 mm diameter, plates up to 85 mm (width) x 8 mm (thickness)

    · Pipes, staffs up to 48 mm diameter and up to 1000 mm length.

    · Finished products (e.g. windows, lenses, prisms, substrates, light conductors etc.)

     

    Specifications:                                                                                                                                            back

    · Dimensions 2 to max. 150 mm
    · Tolerances up to ±0,05 mm and better
    · Thickness 0,30 until max. 60 mm 
    · Surface quality 10/5 in accordance with MIL
    · Parallelism < 10 arc-seconds
    · Flatness λ/8 at 633 nm 
    · Roughness < 5 Angstroms
    · Polishing in accordance with DIN3140 and even better
    · Orientation: C-Plane, R-Plane, A-Plane
    · Tolerance: Usually ± 2° and even better

     

    Testing / Quality Control:                                                                                                                          back

     
    Yet during manufacture process our products are strictly inspected..
    For measurements we use, amongst others,
    dreidimensionale optische Messeinrichtungen, 200-times enlarging mikroscopes, WLI etc.
    Inspection reports and certificates of conformance are routinely supplied.

     

     

     

     

     

     

     

     

     

     

     

     

     

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    GWI Sapphire — Birkenstr. 5 — D-91287 Plech