Long-distance fiber Bragg grating sensor system with a high optical signal-to-noise ratio based on a tunable fiber ring laser configuration

Abstract

A novel tunable fiber ring laser configuration with a combination of bidirectional Raman amplification and dual erbium-doped fiber (EDF) amplification is proposed for realizing high optical signal-to-noise ratio (SNR), long-distance, quasi-distributed fiber Bragg grating (FBG) sensing systems with large capacities and low cost. The hybrid Raman-EDF amplification configuration arranged in the ring laser can enhance the optical SNR of FBG sensor signals significantly owing to the good combination of the high gain of the erbium-doped fiber amplifier (EDFA) and the low noise of the Raman amplification. Such a sensing system can support a large number of FBG sensors because of the use of a tunable fiber Fabry-Perot filter located within the ring laser and spatial division multiplexing for expansion of sensor channels. Experimental results show that an excellent optical SNR of approximately 60 dB has been achieved for a 50 km transmission distance with a low Raman pump power of approximately 170 mW at a wavelength of 1455 nm and a low EDFA pump power of approximately 40 mW at a wavelength of 980 nm, which is the highest optical SNR achieved so far for a 50 km long FBG sensor system, to our knowledge.

Multi-Wavelength Fiber Lasers

“…These topologies offer a stable operation without the necessity of passive multiring cavities [63] or polarization maintaining fiber [64], are suitable for the selection of all the possible output combinations of several different lasing wavelengths and they have been used for remote sensing up to 50 km [65]. In addition to this, in [66], an approach using a tunable fiber ring laser with hybrid Raman-Erbium-doped fiber amplification was demonstrated, obtaining an optical SNR of 60 dB for 50 km. However, ultra-long distance FBG multiplexing systems have been demonstrated [67] without using optical amplification, obtaining acceptable signal to noise ratios (20 dB) after 120 km.…”

“…There were several methods used to improving the sensing distance of FBG-based sensor systems [103]. Based on a tunable laser and optical amplification, a sensing distance of 100km was achieved with a SNR of about 57 dB [104].…”

Study on fiber-optic low-coherence interferometric and fiber Bragg grating sensors

“…We proposed an approach using a tunable fiber ring laser with hybrid erbium-doped fiber (EDF) and Raman amplification to achieve an optical SNR of more than 60 dB after 50-km transmission [53].…”

Hybrid OTDR-Fiber Laser System for Remote Sensor Multiplexing

“…Some approaches of long-distance sensing systems used for simultaneous measuring of different parameters, which offer a good signal-to-noise ratio (SNR) can be found in the literature. In most cases, fiber Bragg grating (FBG)-based sensors have been chosen as the sensing technology due to its advantages, including WDM multiplexing [9]- [12]. Multiwavelength fiber lasers have attracted great interest because of their potential application in different fields: optical fiber sensors, optical signal processing, sensor network multiplexing schemes [13], or instrument testing.…”