A Method for Fabrication of Optical Waveguides of Excellent Thermal Stability in Single-Crystal Sapphire Wafer and Fibers

Background:

Single-crystal sapphire optics offer a promising method for sensing physical data in harsh-environment manufacturing processes. Unfortunately, the use of this technology has been limited due to lack of a thermally stable optical waveguide or cladding structure within the sapphire wafers or fibers that could be used for this purpose. This is due to the difficulty of finding a cladding material that satisfies all the stringent requirements (such as low refractive index, chemical corrosion, and matching the thermal expansion of sapphire crystals) required for harsh environment sensing. Previous techniques, based on thin film deposition or chemical synthesis of dissimilar materials on sapphire surfaces, have yet to satisfy these requirements.

Technology Overview:

This technology enables the deployment of single-crystal sapphire optical fibers and waveguides for harsh-environment sensing by providing a viable solution for effectively confining light signals within sapphire. This method is based on hydrogen ion implantation followed by thermal annealing at high temperatures. The optical waveguides or cladding structures, fabricated in single-crystal sapphire wafers and fibers, can withstand a very high temperature (~1700 C) and function even in some extreme conditions with radiation and corrosion.

Advantages:

- Maintains thermal stability in a long term under harsh-environment sensing conditions.
- Low refractive index.
- Low chemical corrosion.
- Matches thermal expansion of sapphire crystals.

Applications:

The primary application for this technology is the production of sensors based on single-crystal sapphire optics.

Intellectual Property Summary:

This technology is protected by US Patent # 6968114 Cladding for high temperature optical component and method of making same.

Licensing Status:

This technology is available for licensing.