First Real-Time Data Recovery for Synchronous QPSK Transmission With Standard DFB Lasers

Abstract
For the first time, synchronous quadrature phase-shift keying data is recovered in real-time after transmission with standard distributed feedback lasers using a digital inphase and quadrature receiver. Forward-error-correction-compatible performance is reached at 800 Mb/s after 63 km of fiber. Self-homodyne operation with an external cavity laser is error-free