Abstract: The invention relates to a fiber optic device (10) for an optical system (100), including: (a) a first fluid container (12) including a fluid inlet (12a), a fluid outlet (12b), and a light transparent window (12c); (b) a second fluid container (14) including a fluid inlet (14a), a fluid outlet (14b), and a light transparent window (14c); and (c) a hollow core optical fiber (16) fluidically connecting fluid outlet (12b) of first fluid container (12) to fluid inlet (14a) of second fluid container (14) and arranged to direct light incident on light transparent window (12c) of first fluid container (12) to light transparent window (14c) of second fluid container (14), wherein hollow core optical fiber (16) is a, preferably twisted, single ring hollow core optical fiber. The invention also relates to optical system (100) including fiber optic device (10) and to a method for optical measurement using optical system (100).

Abstract: Disclosed is an acoustic transducer for converting a sound signal into an electric signal, including a mobile element movable under the effect of the sound signal, a fixed element opposite the mobile element, a recess, and a dissipative element between the mobile and fixed elements. The coupled system has a natural frequency corresponding to a resonance frequency of the transducer set at maximum sensitivity. The mobile element, the fixed element, the dissipative element and the recess are configured so the quality factor of the acoustic transducer>2. The recess has a straight prismatic, cylindrical, or frustoconical shape, the mobile element forming a first base of the prism, cylinder, or frustum, the fixed element being inside the prism, cylinder or frustum, over the second base of the prism, cylinder or frustum. Such a transducer also incorporates an analogue filtering function for filtering the signal around the natural frequency of same.

Abstract: Disclosed is an acoustic transducer for converting a sound signal into an electric signal, including a mobile element movable under the effect of the sound signal, a fixed element opposite the mobile element, a recess, and a dissipative element between the mobile and fixed elements. The coupled system has a natural frequency corresponding to a resonance frequency of the transducer set at maximum sensitivity. The mobile element, the fixed element, the dissipative element and the recess are configured so the quality factor of the acoustic transducer>2. The recess has a straight prismatic, cylindrical, or frustoconical shape, the mobile element forming a first base of the prism, cylinder, or frustum, the fixed element being inside the prism, cylinder or frustum, over the second base of the prism, cylinder or frustum. Such a transducer also incorporates an analogue filtering function for filtering the signal around the natural frequency of same.