Optimization of the Available Spectrum of a WDM Sensors Network Using a Mode-Locked Laser

Abstract

This work experimentally proposes a new interrogation method which consists on the combination of the information given by both domains: time and frequency. On the one hand, the sensor information is obtained in the frequency domain as usual and, on the other hand, the detection of the different pulses generated through mode locking allows the identification of each FBG. It has been proved that FBGs spaced less than 0.15 nm can be interrogated. The sensor network based on simple ring Erbium doped fiber laser using the FBGs, located in a serial configuration, as wavelength selective reflectors for the lasing structure, acting them also as the sensing transducers elements.

L-band mode-locked femtosecond fiber laser with gigahertz repetition rate

“…At the wavelength of 1608.8 nm, the used EDF has an anomalous dispersion of -26.4 fs 2 /mm and the normal dispersion of the SESAM is ~800 fs 2 , thus the net intracavity dispersion is estimated to be -4480 fs 2 , which make the laser operate at soliton regime. The SESAM has 18% modulation depth, 30% absorbance and 5 ps recovery time.…”

“…Fiber lasers at L-band (1565 nm-1625 nm) have attracted much attention due to their important role in many applications, including expanding the telecommunication window in optical communications [1,2], reducing scattering and absorption to allow surgery in edematous corneas [3], increasing the transmission in brain tissue for biological imaging [4,5]. In the past decades L-band fiber lasers have been widely investigated and dramatic improvements of L-band EDFLs have been made by researchers .…”

64-fs L-band Pulse Generation by an All-Fibre Er-Doped Laser

“…Femtosecond fibre oscillators offer significant advantages over solid-state systems because of their simplicity, cost, and reliability. Ultrashort erbium-doped fibre lasers (EDFLs) working in the 1.6 m band have attracted much attention in recent years, owing to their capability to expand the band of telecommunications and sensing [1], [2] , and their wide applications in spectroscopy, biomedical diagnostics and surgery. Operation of EDFLs at 1.6 m can be realised through control of the linear cavity loss [3] and based on this principle, a number of studies on L-band EDFLs mode-locked through nonlinear polarisation rotation (NPR) or saturable absorbers have been reported [4], [5] .…”

Optical code division multiplexing in the design of encoded fiber Bragg grating sensors

“…However, in both cases the FBG arrays are static in both, reflectivity and Bragg wavelength and thus not acting as sensors. Another approach is presented in [9], where the measurement system is based on a Mode-Locked Laser created by an array of paired FBGs, thus, the sensing information is encoded in the resonant wavelength of each cavity. Identification of the sensing signals is accomplished by wavelength and time signal measurements.…”