Patent ID: 10883890

Abstract:
Fibre linear cavity ring down device for decay time-based attenuation sensing, comprising a bi-directional fibre optic coupler having two fibre port coupling sides, a left-hand port side and a right-hand port side, and a port mirror; wherein signal input on one of said sides is coupled to signal output on the other of said sides; wherein the left-hand port side comprises a first fibre port (port 1) for coupling to an optical light source, the left-hand port side comprises a second fibre port (port 2) coupled to said port mirror (mirror 2), and the right-hand port side comprises a third fibre port (port 3) for coupling to a sensor fibre comprising one or more sensors and optically terminated by a sensor fibre mirror (mirror 1). The optical light source may be also an optical light receiver. The optical light source and receiver may preferably be an optical time domain reflectometer.