Optical Fiber Networks for Remote Fiber Optic Sensors

Abstract

This paper presents an overview of optical fiber sensor networks for remote sensing. Firstly, the state of the art of remote fiber sensor systems has been considered. We have summarized the great evolution of these systems in recent years; this progress confirms that fiber-optic remote sensing is a promising technology with a wide field of practical applications. Afterwards, the most representative remote fiber-optic sensor systems are briefly explained, discussing their schemes, challenges, pros and cons. Finally, a synopsis of the main factors to take into consideration in the design of a remote sensor system is gathered.

200-km long fiber ring laser for multiplexing fiber Bragg gratings arrays

“…Different optical fiber systems striving to increase the distance between the sensor and the processing unit in tens or even hundreds of kilometers can be found in the literature [5]. The former were based on broadband light sources but they were distance-limited by a maximum of 50 km because Rayleigh Scattering noise masks the interrogation signal [6].…”

“…These potential practical applications are the justification of the growing interest of this appealing field. In general, the pivotal idea behind remote sensing concept is the continuous monitoring of structures from a central station located tens or hundreds of kilometers away from the field through the critical location of sensors, which send information to the central station, without the necessity of electrical power feeds in the remote locations [5]. This remote capability allows immediate damage detection so that necessary actions can be quickly taken.…”

Fiber optic sensor networks based on OADM devices with a bus configuration

“…Civil infrastructures, such as bridges, piles, tunnels, dams, gas or oil pipelines, river banks and offshore platforms are the most common applications just to mention some. [1][2][3][4][5] The design of the fiber optical sensor networks is not a straightforward task since diverse aspects must be considered: network topology, inclusion or not of optical amplification, type of multiplexed sensors, and in addition to the purely optical parameters, other issues associated with the network complexity, maintenance aspects and, last but not least, the cost [6]. Regarding network topology, the four most common topologies are serial, bus, star and tree.…”

“…The combination of the entire aforementioned aspects offer a broad range of alternatives which ascribe the fiber optical sensor networks a wide versatility. Consequently, flexible fiber optical sensors networks are particularly appealing for the multiplexing of different sensors on the same structure to provide an adequate solution for almost all kind of applications and environments [1][2][3][4][5].…”

A precision fiber Bragg grating interrogation system using long-wavelength vertical-cavity surface-emitting laser

“…The conventional gain control solutions using digital potentiometers require regulation for many times and sometimes fail. Alternatively, the LA (i.e., AD8305) can convert the PD current to a voltage with a precise logarithmic relationship and provides a large dynamic range up to 100 dB, thus more adaptive in field applications [11]. Figure 3 shows the standard signal s V , the reference signal r V , and the normalized signal n V .…”