Glass Lens & Windows

Subsea Batteries

Subsea Batteries

POWER UNDER PRESSURE Pressure Tolerant Li-Po Batteries for underwater vehicles

Hydrospace customers select sapphire glass for its extraordinary durability and optical transparency. A typical application would be to use a quality sapphire glass optical dome cover for underwater photography deployed on a ROV, Subsea camera, or a drone. Additionally, our sapphire lenses can be found on scientific instrumentation or equipment for military, space, medical, optical communication, photoelectric or mechanical applications.



Typical Images

Sapphire ROund Lens 1
Sapphire Optics Lens 2
Sapphire Domes
light guide 4
Glass Hyperdome
1.2 Sapphire Windows

Typical Materials

  • Sapphire
  • BK7
  • K9
  • Fused Silica
  • Quartz

Typical Geometries

  • Square
  • Flat Disc
  • Hemispherical Domes
  • Cylindrical
  • Custom

Typical Sizes and Tolerances

  • Diameter: 3 mm – 300mm     

  • Thickness: 0.5 mm-20mm      

  • Tolerance: +/- 0.05 mm

Why choose Sapphire Glass instead of Acrylic?

Choosing the right material for a project often comes down to analyzing trade-offs. The durability of glasses and softer materials like acrylic can be placed on a scale: harder materials are more scratch-resistant but are less resilient against cracks, while softer materials like acrylics are more crack-resilient but less scratch-resistant. Harder materials are fundamentally more brittle than softer ones so sapphire glass is still susceptible to cracking and shattering despite having high resistance against scratches.


The Material:

Synthetic sapphire is generally produced by subjecting aluminum oxide powder under extreme heat and pressure and then annealing it to remove internal stress. The resulting material is more transparent and durable than standard glass.



The material is nearly twice as hard as standard glass and is almost as hard as a diamond. Sapphire has a value of 9 on the Mohs scale of mineral hardness, the third hardest natural substance. This means that sapphire glass is almost resistant to scratch unless it comes in direct and hard abrasive contact with a diamond. Sapphire glass is not only hard but also strong. It has similar properties with naturally-occurring sapphire with a compressive strength of 2000 MPa (290 Ksi). This makes the material almost 10 times stronger than stainless steel. Resistance to thermal shock is also an advantage of sapphire glass.


Optical Properties:

Although sapphires are blue in color, a sapphire glass is highly transparent to wavelengths of light between 150 nanometers and 5500 nanometers. This range gives the material a very wide optical transmission band from ultraviolet to near-infrared–the human eye can only discern wavelengths between 380 nanometers and 750 nanometers.  



Sapphire glass manufacturing process requires extreme heat (> 2000 C) to melt and precision manufacturing. This makes sapphire production more expensive and is mainly used for high precision and mission critical engineering applications such as deep ocean operation.


To order glass windows, send us a drawing or provide general geometry and dimensions. We will provide a suggested design and a cost quotation. Also provide us with optical specifications, and surface coating requirements, if applicable.

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