Optical particle detector and method of manufacturing the same

An optical particle detector comprising:

• at least one channel intended to receive a fluid carrying at least one particle, and across which light rays are intended to pass such that said light rays are partially scattered by the at least one particle,
• a plurality of photodetectors capable of receiving said scattered light rays,
• wherein said detector comprises at least one optical waveguide comprising at least a first part and a second part separated from one another by the channel, the first part of the waveguide having a first entrance and a first exit opening out onto the channel and the second part of the waveguide having a second entrance and a second exit opening out onto the channel, said first and second parts being arranged in such a way that the first entrance faces the second exit and the second entrance faces the first exit, the optical waveguide being configured to:
• collect, at least at one entrance of the waveguide from among the first and second entrances, light rays that were not scattered by the at least one particle and having crossed the channel, and to
• reinject said unscattered light rays into the channel through at least one exit of the waveguide from among the first and second exits.

A method for manufacturing an optical particle detector comprising:

• at least one channel intended to receive a fluid carrying at least one particle, and across which light rays are intended to pass such that said light rays are partially scattered by the at least one particle,
• a plurality of photodetectors capable of receiving said scattered light rays,
• at least one optical waveguide configured to:
• collect light rays not scattered by the at least one particle, and to
• reinject said unscattered light rays into the channel,
• said manufacturing method comprising the following steps of:
• providing a substrate,
• forming the optical waveguide by implanting ions into the substrate,
• forming the channel by drilling into at least the substrate at the optical waveguide, such that said channel crosses the optical waveguide, the optical waveguide thus comprising at least a first part and a second part separated from one another by the channel, the first part of the waveguide having a first entrance and a first exit opening out onto the channel and the second part of the waveguide having a second entrance and a second exit opening out onto the channel, said first and second parts being arranged in such a way that the first entrance faces the second exit and the second entrance faces the first exit,
• providing a plurality of photodetectors,
• assembling the photodetectors of said plurality with the substrate, by disposing the photodetectors at least partially around the channel.