Francesco Cisternino

Polarization measurements on single-mode fibers

An overview of current measurement techniques on conventional and polarization maintaining single-mode fibers is presented. The various methods are discussed and classified with respect to the relevant polarization parameters. Applicability ranges and resolution are pointed out for different types of fibers. >

Coherent Transmission With Polarization Modulation: Experimental Results And System Analysis

The polarization modulation technique with two different detection schemes is analyzed. A first experimen-tal test for demonstrating the principle of differential heterodyne detection has been performed. Many computer simulations at high and low bit-rates yield a performance complete equality of the two systems.

A new approach to investigating mode coupling phenomena in graded-index optical fibres

To study mode coupling in optical fibres a new technique is developed, based on mode selective excitation and output near-field analysis. Experimental results support decoupling of the problem into two phenomena which are effective on different scales of propagation length: azimuthal and longitudinal mode mixing. A statistical model providing a simulation of the experimental near-field patterns is developed. Comparison with measurements shows that azimuthal mixing is complete before 1 km propagation, while effects of uncomplete axial coupling are accounted for. This approach also suggests a method for measuring the steady-state distribution length, with useful system implications.

A heterodyne interferometric polarimeter for the detection of jones and stokes polarization vectors

Abstract A heterodyne interferometric polarimeter for detection of the Jones components and Stokes parameters is demonstrated. The measurement of both sets of quantities for various polarization states is achieved with excellent precision. The details of the corresponding Lissajous picture (ellipse) can be visualized in real time. Finally, the polarization data collected at the output of a highly birefringent fiber have been used for submillimetric beat-Length measurements.

Real-Time Heterodyne Fibre Polarimetry by Means of Jones and Stokes Vector Detection

The study and measurement of the state of polarization (SOP) of the light propagating along a single-mode optical fibre, has been receiving particular attention in recent applications, such as coherent optical communications and fibre sensors [1, 2]. In both cases the polarization analysis requires a dynamical measurement of the SOP at the fiber output, which can be done on the basis of the Jones vector [3] (in terms of the amplitude ratio R and the relative phase Φ of the two components of the electric field) or of the Stokes vector [4] (in terms of the intensity parameters usually represented on the Poincare sphere to describe a fully polarized beam: s0, s1, s2, s3).

Mach-Zehnder Systems for Heterodyne Fibre Polarimetry in Different Coherence Conditions

In this contribution two distinct types of heterodyne systems are presented for the fast detection of polarization states at the output of a single -mode fibre. Based on the same measurement principle, the two versions differ as to source coherence properties, in order to cover a wider range of application conditions. Though devoted to fibre characterization purposes in the area of optical communications, the present work can be of considerable interest also for the development of new polarimetric fibre optic sensors.