Brillouin optical distributed sensing device and method with improved tolerance to sensor failure

A Brillouin optical distributed sensing device, comprising:

• means for generating an optical pulsed signal and an optical probe signal;
• circulation means for directing said optical pulsed signal to a sensing optical fiber, and for directing an optical measurement signal with Brillouin scattering information arising from said sensing optical fiber toward detection means;
• optical routing means for configuring the device so as to allow generating:
• according to a first configuration, an optical measurement signal with stimulated Brillouin scattering information resulting from the interaction of the optical pulsed signal and an optical probe signal propagating in said sensing optical fiber in a direction opposite to the optical pulsed signal;
• and
• according to a second configuration, an optical measurement signal with spontaneous Brillouin scattering information resulting from the propagation of the optical pulsed signal in the sensing optical fiber,
• optical routing means being arranged for directing the optical probe signal:
• according to the first configuration, to the sensing optical fiber so that said optical probe signal propagates in said sensing optical fiber in a direction opposite to the optical pulsed signal, the optical probe signal and the optical pulsed signal propagating in said sensing optical fiber according to the first configuration;
• and
• according to the second configuration, to coupling means inserted between the circulating means and the detection means so as to combine said optical probe signal and said measurement signal on the detection means, so that the optical pulsed signal propagates in said sensing optical fiber according to the second configuration but the optical probe signal does not propagate in said sensing optical fiber according to the second configuration.