Abstract: A method for producing a ridge optical waveguide having low coupling losses between the ridge optical waveguide and an optical fiber includes forming on the surface of a dielectric substrate an optical waveguide having a first end and a second end opposite the first end; cutting out two parallel recesses spaced apart by a distance wr on the surface of the dielectric substrate to form a rigid optical waveguide with an increased width (wr) between the two recesses. The recesses are cut such that the depth of each recess changes continuously and gradually between a zero depth at the height of the first end of the optical waveguide and a maximum depth (Hm) at a pre-determined distance (Ip) from the first end.

Abstract: The present invention is based on the fmding that bacterial Volatile Organic Compounds (VOCs) of bacterial strains belonging to the Bacillus genus have an insect repellent activity and can accordingly be used as insect repellents. In particular the VOCs released by blends of such Bacillus strains comprising at least one Bacillus aerius strain, showed a repellent activity against insects like Anopheles gambiae s. s. and Aedes aegypti. It is accordingly an object of the present invention to provide the use of VOCs of bacterial strains belonging to the Bacillus genus as insect repellents. It further provides the use of bacterial strains belonging to the Bacillus genus as insect repellents, in particular the use of Bacillus aerius strains as insect repellents. It also provides the use of blends of bacterial strains belonging to the Bacillus genus as insect repellents, in particular blends comprising at least one Bacillus aerius strain.