Abstract: A device for determining a refractive index may be provided. The device including at least one waveguide having a core and a cladding surrounding the core, the cladding being at least partly removed in at least one first longitudinal portion and the core including at least one fiber Bragg grating in at least one second longitudinal portion. A method for determining a refractive index or a pressure change in a fluid may also provided. The method may include at least one waveguide having a core and a cladding surrounding the core, the cladding being at least partly removed in at least one longitudinal portion. A method for producing such a device may also be provided.

Abstract: The invention relates to a method and a device for producing at least one fiber Bragg grating in a waveguide, wherein the waveguide has at least one core having a first refractive index and the fiber Bragg grating contains a plurality of spatial regions which each occupy a partial volume of the core and have a second refractive index, wherein the spatial regions are each produced by the action of laser radiation on a partial volume of the core, wherein the laser radiation contains a plurality of pulse trains each containing a plurality of individual pulses, wherein the time interval between successive individual pulses is smaller than the time interval between successive pulse trains and the time interval between successive individual pulses is chosen between 10 ns and 100 ps or the pulse train has a duration of 50 fs to 50 ps.

Abstract: A device for determining a refractive index may be provided. The device including at least one waveguide having a core and a cladding surrounding the core, the cladding being at least partly removed in at least one first longitudinal portion and the core including at least one fiber Bragg grating in at least one second longitudinal portion. A method for determining a refractive index or a pressure change in a fluid may also provided. The method may include at least one waveguide having a core and a cladding surrounding the core, the cladding being at least partly removed in at least one longitudinal portion. A method for producing such a device may also be provided.

Abstract: The invention relates to a fiber-optic sensor comprising an optical waveguide having at least one first core and a cladding surrounding the first core, wherein the first core extends substantially over the entire length of the optical waveguide, wherein the sensor has at least one second core which is at least partly surrounded by the cladding, wherein the longitudinal extent of the second core is less than the total length of the optical waveguide and at least one Bragg grating is introduced into the second core. Furthermore, the invention relates to a use of the fiber-optic sensor.

Abstract: The invention relates to a fibre-optic sensor comprising an optical waveguide having at least one first core and a cladding surrounding the first core, wherein the first core extends substantially over the entire length of the optical waveguide, wherein the sensor has at least one second core which is at least partly surrounded by the cladding, wherein the longitudinal extent of the second core is less than the total length of the optical waveguide and at least one Bragg grating is introduced into the second core. Furthermore, the invention relates to a use of the fibre-optic sensor.

Abstract: The invention relates to a method and a device for producing at least one fibre Bragg grating in a waveguide, wherein the waveguide has at least one core having a first refractive index and the fibre Bragg grating contains a plurality of spatial regions which each occupy a partial volume of the core and have a second refractive index, wherein the spatial regions are each produced by the action of laser radiation on a partial volume of the core, wherein the laser radiation contains a plurality of pulse trains each containing a plurality of individual pulses, wherein the time interval between successive individual pulses is smaller than the time interval between successive pulse trains and the time interval between successive individual pulses is chosen between 10 ns and 100 ps or the pulse train has a duration of 50 fs to 50 ps.