Direct Modulation of a Laser Using 112-Gb/s 16-QAM Nyquist Subcarrier Modulation

A 112-Gb/s single-carrier, single-polarization short reach transmission system using a high bandwidth 1310 nm directly modulated laser is demonstrated. Spectrally efficient signal generation is achieved by using: 1) half-cycle Nyquist subcarrier modulation with 16-ary quadrature-amplitude-modulation; 2) pre-compensation for the frequency response of the end-toend system; and 3) and a Volterra nonlinear equalizer to postcompensate for the nonlinear modulation dynamics of the laser. Digital signal processing techniques for signal recovery enable transmission over 20 km of standard single mode fiber with a bit error ratio below the 7% overhead hard-decision forward error correction coding threshold of 4.6 × 10
^-3
at a received optical power of -5.25 dBm.