Journal: Measurement Science and Technology
Paper: Switchable multi-wavelength erbium-doped fibre laser for remote sensing

AUTHORS: R. A. Perez-Herrera, S. Diaz, M. Fernandez-Vallejo, M. Lopez-Amo, M. A. Quintela, J. M. Lopez-Higuera
Abstracts:
In this work, we present and experimentally demonstrate a switchable Erbium-doped fibre laser (EDFL) for remote sensing applications. The laser uses four Fibre Bragg Gratings (FBGs) for wavelength selection and for temperature sensing and a 2x4 optical switch. By adjusting the switch combinations, the laser can be switched among the four different wavelength lasing configurations. Stable one- and two- wavelength oscillations were achieved based on the use of this device. An output power instability analysis with the temperature for two different multi-wavelength configurations, one of them using the 2x4 optical switch and the other using a 1x4 coupler, was performed, for a cavity length of 50 km. A comparison between the performances of these topologies is carried out, and their temperature sensitivity and stabilization time are shown.

Journal: Optical Fiber Technology
Paper: Stability comparison of two quadruple-wavelength switchable erbium-doped fiber lasers

AUTHORS: Rosa Ana Perez; Montserrat Fernández-Vallejo; Silvia Diaz; M. Angeles Quintela;
Manuel Lopez-Amo; José Miguel López-Higuera
Abstracts:
An experimental stability comparison between two different switchable Erbium-doped fiber lasers (EDFL) is carried out. Both topologies use fiber Bragg grating reflectors in order to select the emission wavelengths and two 2x4 optical switches. By adjusting the switches combinations, the lasers can be switched among the sixteen different wavelength lasing configurations. An output power and wavelength instability analysis with time for both topologies was performed. The experimental results confirm that the topology based on a serial configuration offers a better stability, efficiency and higher optical signal to noise ratios (OSNR) than the one based on a parallel configuration.

Journal: Measurement Science and Technology
Paper: Experimental characterization of spectral effective index dependence of the index-guided photonic crystal fibers

AUTHORS: José M. Lázaro; Antonio Quintela, Karol Tarnowski, Jan Wojcik, Waclaw Urbanczyk, José M. López-Higuera
Abstracts:
The effective index of index-guided photonic crystal fibers (IG-PCF) is experimentally obtained as a function of the wavelength by writing fiber Bragg gratings (FBG) in the fibers. The results are found to be in good agreement with theoretical simulations and are also discussed and compared with measurements on standard telecommunication fibers. Differences between the fibers were observed both in the Bragg grating inscription process and in the fiber effective index value evolution with the wavelength, which depends on the fiber cladding microstructure. Index evolution slopes of -2.029x10-5 nm-1, -2.044x10-5 nm-1 and -1.388x10-5 nm-1 were measured for the two IG-PCFs and the standard fiber, respectively.