  Determined polarization state of light is required in nonlinear optics
applications related to ultrashort and single-cycle light pulse generation.
Such short time scales require up to full octave of spectral width of light.
Fiber-based, pulse-preserving and linearly polarized supercontinuum can meet
these requirements. We report on the development - from linear simulations of
the fiber structure, through fabrication of physical fibers to their versatile
characterization - of polarization maintaining, highly nonlinear photonic
crystal fibers, intended for femtosecond pumping at a wavelength of 1560 nm.
Full octave of linearly polarized light around this wavelength would enable to
cover amplification bandwidths of the three major fiber amplifiers from
ytterbium doped systems up to thulium and holmium doped fiber amplifiers, with
a coherent, linearly polarized seed signal. At the same time, an all-normal
chromatic dispersion profile over an entire transmission window, and small
dispersion of nonlinearity in the developed fibers, would facilitate use of
commercially available femtosecond fiber lasers as pump sources for the
developed fibers.
