Measurement and modelling of dispersion characteristics of a two-mode birefringent holey fibre

Abstract

Employing several interferometric methods, we measured in a broad spectral range the wavelength dependences of the phase modal birefringence and the polarization mode dispersion for the LP01 and even LP11 spatial modes supported by a birefringent holey fibre. We also determined the wavelength dependence of the intermodal dispersion between the X- and Y-polarized LP01 and even LP11 spatial modes. Furthermore, using a full-vector finite-element method, we modelled all the measured dispersion characteristics and demonstrated good agreement between experimental and theoretical results.

Measurement of the group dispersion of the fundamental mode of holey fiber by white-light spectral interferometry

“…1 as lens 1 and lens 2) represented by a microscope objective (10×/0.30, Meopta), and an achromatic lens (74-ACR, Ocean Optics, Inc.). The fiber sample is pure silica holey fiber (PM-1550-01, Thorlabs) [17] of length z = (50650 ± 10) μm.…”

“…To find the eigenpairs of the above equation, we used the Arnoldi method as an eigensolver and an unsymmetrical multifrontal method as a solver of linear system of equations. The calculations were carried out for the real geometry of the fiber [17]. The binary image of the fiber cross section shown in Fig.…”

Group index dispersion of holey fibres measured by a white-light spectral interferometric technique

“…Similarly, the ellipticalshape optical field indicated that the light was guided by the fiber core and the fundamental mode was supported. The orientation of the polarizer was along the longer or shorter axis of the elliptical core so that the group dispersion in the X or Y polarization [12] was measured.…”

“…We measured two different fibre samples. The first sample is pure silica holey fibre of length z = 50650 µm (PM-1550-01, Thorlabs, see its SEM photograph in [12]). The second sample is a rectangular-shape highly birefringent holey fibre of length z = 54200 µm made of SK222 optical glass with rectangular lattice and circular holes (see a similar fibre of IEMT with elliptical holes in [18]).…”

“…Using a low-resolution spectrometer [9], the measurement of the group refractive index dispersion of a given fibre is still possible in the vicinity of the stationary phase point if one moves it in successive steps to different wavelengths and repeats the measurement. The modification of the technique with a tandem configuration of a Michelson interferometer and an optical fibre has been used in measurement of the group dispersion in birefringent fibres [10][11][12] of known lengths. Recently, the use of the method with a Mach-Zehnder interferometer was extended for dispersion characterization of tapered fibres [7] or glasses of optical fibres [13].…”