Optical all-pass filters for polarization mode dispersion compensation

Polarization mode dispersion (PMD) compensation is addressed by decompositi on of a fiber's Jones matrix into amplitude and phase responses, which are then compensated for separately. Cubic and higher-order phase compensation substantially reduce the cumulative probability at a given system penalty o ver first-order PMD compensation, as demonstrated for a 40-Gbit/s non-retur n-to-zero signal and a fiber PMD with a differential group delay of 20 ps ( rms). Single-stage all-pass filters provide tunable compensation that is co mparable to that obtained with a variable-delay line, and multistage all-pa ss filters are well suited for higher-order phase compensation. (C) 2000 Op tical Society of America. OCIS codes: 260.2030, 060.4370, 060.2360, 350.503 0, 060.2430.