Abstract: Optical system comprising two optical fibres which are configured to define between them a Fabry-Perot cavity, and a connecting element bonded to each of the two optical fibres, the connecting element defining a through-passage, at least one of the two optical fibres comprising an end portion arranged in the through-passage and bonded to the connecting element, the two optical fibres extending along an axis and being separated from one another by a distance Le parallel to the axis, one of the optical fibres being bonded to the connecting element at a first bonding zone, and the other optical fibre being bonded to the connecting element at a second bonding zone separated from the first bonding zone by distance parallel to the axis.

Abstract: Optical system (20) comprising two optical fibres (3, 5) which are configured to define between them a Fabry-Perot cavity, and a connecting element (7) bonded to each of the two optical fibres (3, 5), the connecting element (7) defining a through-passage, at least one of the two optical fibres (3, 5) comprising an end portion (22, 23) arranged in the through-passage and bonded to the connecting element (7), the two optical fibres (3, 5) extending along an axis (A) and being separated from one another by a distance Lc parallel to the axis (A), one of the optical fibres being bonded to the connecting element at a first bonding zone, and the other optical fibre being bonded to the connecting element at a second bonding zone separated from the first bonding zone by distance L1 parallel to the axis (A), wherein the two optical fibres (3, 5) have a first thermal expansion coefficient, and the connecting element (7) has a second thermal expansion coefficient, so that the first thermal expansion coefficient is equal