Single-mode Dispersion-shifted Fiber Research Articles

All-optical generation of Brillouin dynamic grating based on multiple acoustic modes in a single-mode dispersion-shifted fiber

We demonstrate an all-optical generation of Brillouin dynamic grating (BDG) in a single-mode dispersion-shifted fiber (DSF). The feature of multiple-peak Brillouin gain spectrum (BGS) owing to the existence of the multiple acoustic modes in the single-mode DSF is utilized. Two inharmonic lock-in detections are newly introduced to characterize the BGS and the frequency-maintained or frequency-shifted BDG reflection. The frequency-shifted property of the BDG in the DSF with hundreds of MHz can find great potential applications in optical fiber sensing or all-optical signal processing.

Fiber four-wave mixing demultiplexing with inherent parametric amplification

We present an all-optical time-division demultiplexer with 22 dB conversion efficiency, using four-wave mixing (FWM) at 1550 nm in a single-mode dispersion-shifted fiber. Error-free demultiplexing of 20 Gb/s data to 10 Gb/s is obtained, with 1.4 dB power penalty at BER=10/sup -9/. We also derive theoretical expressions for the conversion efficiency, the maximum bit rate that is possible to demur and the shape of the switching window. In particular we emphasize the importance of phase-matching in order to achieve a flat switching window. Furthermore the pump must remain undepleted to avoid a detrimental reduction of the extinction ratio due to instantaneous parametric gain saturation.

Evolution of the bandwidth of the principal states of polarization in single-mode fibers

The bandwidth in which the first-order approximation of the principal states of polarization of a single-mode fiber can be assumed valid is examined. The principal states of polarization and their bandwidth are found for a fiber with both constant coupling and birefringence, and the relationship with the fiber's eigenmodes is examined. On the basis of these results, a fiber cascade is analyzed, and a Monte Carlo simulation provides theoretical values of the bandwidth that have been experimentally verified on a 2-km-long concatenation of single-mode dispersion-shifted fibers.