Patent ID: 7224906
Filing Date: 2007-05-29
Classification: G02F,H04B,H04J,H04L

Abstract:
1. A fiber optic network for carrying optical signals, comprising: at least one optical fiber for carrying an optical signal comprising return-to-zero phase-shift-keyed (PSK) optical pulses; at least one laser to generate a cw optical signal; at least one pulse modulator to transform cw optical signal into a pulsed return-to-zero (RZ) optical signal; the pulse modulator having a bias and the drive voltage to form optical pulses selected to achieve maximal spectral efficiency of PSK transmission, the bias and the drive voltage of the pulse modulator selected to form optical pulses that mitigate non-linearities of the fiber transmission line and minimize adjacent channel crosstalk, the bias and the drive voltage of the pulse modulator are selected according to the characteristics of laser optical power, network channel spacing, the fiber transmission line length, the fiber transmission line dispersion, and non-linearities of the fiber transmission network that minimizes the bit-error-rate of the transmitted signal, the pulse modulator configured to use electro-optics to generate optical pulses using amplitude modulation of a cw optical signal; at least one PSK modulator connected to the pulse modulator to encode the data producing RZ-PSK signal for transmission in the fiber optic network; a WDM combiner connected to the PSK modulator to combine the multiple RZ-PSK optical signals corresponding to multiple channels with arbitrary polarization states including at least one of linear, circular, or elliptical.