Experimental Demonstration of Real-Time Optical OFDM Transmission at 11.25 Gb/s Over 500-m MMFs Employing Directly Modulated DFB Lasers

The fastest ever 11.25-Gb/s real-time end-to-end optical orthogonal frequency-division-multiplexing (OOFDM) transmission over 500-m multimode fibers (MMFs) with a high electrical spectral efficiency of 5.625 bit/s/Hz is experimentally demonstrated, for the first time, in a simple intensity modulation and direct detection (IMDD) system employing a directly modulated distributed-feedback (DFB) laser. An optical power budget as high as 12 dB is achieved with a minimum received optical power of -6.3 dBm for a total channel bit-error rate of 1 × 10^-3. The field programmable gate array (FPGA)-based OOFDM transceivers also have functionalities including variable power loading, performance monitoring, and on-line parameter adjustment.