Simplified optical correlation-domain reflectometry employing proximal reflection point

Abstract

We develop a new configuration of simplified optical correlation-domain reflectometry using a proximal reflection point. The experimental setup is basically composed of standard silica fibers and includes neither an optical frequency shifter such as an acousto-optic modulator nor an explicit reference path. The light reflected at the proximal reflection point, which is artificially fabricated near an optical circulator, is used as the reference light. Unlike the conventional silica-based setup, this configuration can perform a distributed reflectivity measurement along the distal half of the sensing fiber. After demonstration of the basic operation, the incident optical power dependence of the reflectivity distribution is investigated, and the existence of the optimal incident power is clarified.

First demonstration of Brillouin optical correlation-domain reflectometry based on external modulation scheme

“…These drawbacks are also found in optical correlationdomain reflectometry (OCDR), [18][19][20][21][22][23] which is a Fresnelreflection-based technique for detecting low-quality connections, splices, and damaged parts along an optical fiber. We have developed a new OCDR configuration based on an external modulation scheme, in which, instead of directly modulating the driving current of a laser, the optical frequency is modulated using an electro-optic modulator (EOM).…”

Simplified setup for Brillouin scattering observation using variable reflectivity mirror and its polarisation characteristics

“…One of these efforts is the elimination of the independent reference light path. Thus far, several methods have been developed that use as reference light the Fresnel reflected light generated at the boundary between the open end of the FUT and air [11], and the boundary between the second port of the optical circulator and the proximal end of the FUT [12,13]. However, these methods present a challenge as the power of the Fresnel reflected light remains constant, hindering the maximisation of the signal-to-noise ratio (SNR) of the BGS through control mechanisms.…”

Observation of Rayleigh scattering by simplified optical correlation-domain reflectometry without frequency shifter

“…As an alternative to OTDR and OFDR, optical correlationdomain reflectometry (OCDR) [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] has been developed on the basis of the synthesis of optical coherence functions. 15) OCDR can be implemented at a relatively low cost and has a unique advantage called random accessibility, i.e.…”