Artificially anisotropic core fiber with ultra-flat high birefringence profile

We present a highly birefringent fiber with a core made of artificial anisotropic glass material. The fiber core is composed of interleaved subwavelength layers of two types of soft glasses ordered in a rectangular structure. A pair of thermally matched glasses, a low refractive index borosilicate glass and a high refractive index lead oxide glass, are used. The fiber has a unique flat profile of birefringence over one octave, weakly dependent on wavelength. The group birefringence and effective mode area were measured in a broadband range across the visible and the near infrared for the fundamental mode and were found to be equal 1.8 x 10(-3) and 20 mu m(2), respectively. The group birefringence is uniquely flat over the wavelength range of 0.8-1.7 mu m and the relative difference of birefringence is below 0.2 x 10(-3). The measured dispersion shows also relatively flat characteristics varying from -60 ps/(nm x km) at 1150 nm to 20 ps/(nm x km) at 1690 nm with Zero Dispersion Wavelength at 1520 nm. We demonstrated an application of the fiber for polarization maintaining broadband supercontinuum generation in the range of 1210-1830 nm when pumped with a subpicosecond fiber-based laser at 1560 nm. (C) 2016 Optical Society of America