Polarization effects in birefringent fiber waveguides with an elliptic borosilicate cladding

Single-mode fiber waveguides with an elliptic borosilicate cladding were developed and their polarization characteristics were studied. It was found that the mode birefringence was independent of the radiation frequency and varied linearly with the fiber waveguide temperature. The length of the beats was ~10 mm at λ=0.85μ, whereas the dispersion of the polarization modes was 300 psec/km. The losses were 5–10 dB/km at λ=0.85μ and the mode coupling parameter was h=2×10^–4m^–1. A study was made of the possibility of using singlemode fiber waveguides for the depolarization of nonmonochromatic radiation and also as tunable delay lines.