International Gemstone Registry Inc.

Institut National D'optional

Institut National D'optique

Bruno Bourliaguet

Daniel Cantin

Marc Levesque

Serge Caron

Alain Cournoyer

Claude Pare

Claude Paré

Yves Champagne

Wes Barron

The invention relates to distributed optical waveguide polarimetric chemical analysis. Real-time monitoring of a separation process of a fluid in a capillary column is provided using a distributed sensor comprising a birefringent optical waveguide placed between two polarizers. The optical waveguide has a longitudinal channel defined by a channel surface in its cladding and adapted to receive the fluid such that it travels in said longitudinal channel. The longitudinal channel is positioned with respect to the core such that channel surface absorption of the fluid traveling in the longitudinal channel causes a local variation of the orientation of the polarization axes of the optical waveguide. The proposed embodiment can be used for monitoring the velocity of the separated components along the channel.

Optical fiber polarimetric chemical sensor

A method and an apparatus for laser marking indicia in the volume of gemstones such as diamonds, the indicia being made up of a plurality of microscopic dot-shaped marks whose build-up can be initiated by exposing naturally-occurring internal defects or impurities in the volume of a gemstone to a tightly focused train of laser pulses. Authentication data is encoded in the gemstone from the relative spatial arrangement of the dot-shaped marks that form the indicium. Taking advantage of the presence of otherwise invisible defects in the gemstone allows for inscribing indicia with laser pulses carrying energies substantially lower than the threshold energy required for inscribing in the volume of a perfect gemstone material. The marking process is then much less susceptible to inflict damages to the surface of the gemstone, and the marking can be performed using a broad variety of femtosecond laser systems. The dot-shaped marks engraved at a depth below the surface of a gemstone can be made undetectable with the unaided eye or with a loupe by limiting their individual size to a few micrometers, while devising indicia made up of only a few marks. As a result, the marking does not detract from the appearance and value of the gemstone. The procedure for laser marking accounts for the random spatial distribution of the defects present in natural gemstones as well as for their strongly localized character. The presence of an indicium can be detected by using a dedicated optical reader that can be afforded by every jewellery store.

Method and system for laser marking in the volume of gemstones such as diamonds

Growing community of inventors

CA

Bruno Bourliaguet