Single-polarization in evolved Fully-Aperiodic LPF design - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2016

Single-polarization in evolved Fully-Aperiodic LPF design

Rémi Du Jeu
  • Fonction : Auteur
Dia Darwich
Romain Dauliat
Aurélien Benoit
  • Fonction : Auteur
  • PersonId : 974266
Philippe Roy

Résumé

Evolutions of fully-aperiodic large-pitch-fibers employing stress-applying parts are presented to ensure the single propagation of one polarization state of the fundamental mode. The polarization properties are investigated with core scalability over a large spectral bandwidth. OCIS codes: (060.4005) Microstructured fibers, (060.2420) Fibers, polarization-maintaining Controlling the polarization state of coherent light is generally addressed by polarization-maintaining design like the well-known PANDA fibers [1], or a single-polarization propagation [2] owing to stress applying parts (SAP). The current study has been focusing on judiciously introducing stress into high power fibers to control the polarization state of the fundamental mode (FM). Fully-aperiodic large-pitch-fibers (FA-LPF) which have proved their potential to delocalize efficiently the HOM out of the gain region [3] are used here as basic concept. The numerical approach consists in adding SAP (low-index boron-doped silica inclusions) in the fiber structure in order to obtain enough birefringence while maintaining the effective single-mode operation. Single-polarization is therefore obtained due to a selective modal coupling of one of the FM polarization state with a HOM. Two designs are shown here, with two (resp. 6) boron inclusions (yellow point in Fig.1) implemented in the FA-LPF called 2SAP (resp. 6SAP). Fibers with different core diameters have been drawn from 40µm to 140µm. Fig 1: Observed near field intensity distributions of the transmitted fundamental mode for several core sizes versus the working wavelength for the two designs (a) FA-LPF 2SAP design and (b) FA-LPF 6SAP design. Each black point represents a measured configuration, and the green area arbitrarily represents the spectral range where the transmission shows a single-mode behavior. On the left of each graph, the fiber numerical design with SAP in yellow, low-index inclusions in light blue and pure silica in dark blue. To characterize these fibers, a supercontinuum source emitting a non-polarized radiation spanning from 400nm to 1700nm was used. The experimental setup consists of launching light into the fiber core and observing the output near field intensity distributions with a CCD camera. Narrow pass-band filters have been introduced to perform a spectral study. The FM suffers deformation due to the vicinity of SAP with the core when the ratio core diameter/wavelength increases. The 6SAP structure allows effective single-mode propagation over a wider area. Results are summed up in Fig.1. Then, a polarizer was added to force the polarization state at some point. Single-polarization propagation behavior was systematically observed for the two designs. A polarization extinction ratio equal to 11.2dB has been measured at 1050nm at the output end of a 50cm long, 60µm core diameter fiber. To conclude two evolutions of the FA-LPF design are reported and single-polarization propagation is obtained over a large spectral band for core diameter up to 140µm especially for the 6SAP structure.
Fichier non déposé

Dates et versions

hal-01645134 , version 1 (22-11-2017)

Identifiants

  • HAL Id : hal-01645134 , version 1

Citer

Rémi Du Jeu, Dia Darwich, Romain Dauliat, Aurélien Benoit, Raphaël Jamier, et al.. Single-polarization in evolved Fully-Aperiodic LPF design. Advanced Photonics 2016 - Specialty Optical Fibers, Jul 2016, Vancouver, Canada. ⟨hal-01645134⟩
55 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More