Wavelength tunability and polarization characteristics of twisted polarization beamsplitting single-mode fiber couplers

The wavelength tunability and the polarization characteristics of twisted p olarization beamsplitting fiber couplers are investigated experimentally an d analyzed theoretically, The measured spectrum transmissions and polarizat ion characteristics agree well with the theoretical results. The wavelength working as a polarization beamsplitter can be tuned in the 1.3-1.75 mum wa velength range without significant degradation. Splitting ratios for orthog onally polarized lights are more than 20 dB and less than -20 dB.