Enhanced Performance for SSB-OFDM Transmission With a Low-Chirp Silicon MRM

While single sideband (SSB) modulation with orthogonal frequency-division multiplexing (OFDM) is used to avoid chromatic dispersion (CD)-induced fading, it is only effective in the absence of chirp. We examine the effectiveness of a extremely wideband silicon photonics (SiP) microring modulator (MRM) modulator designed for low chirp operation. We identify and confirm via simulation and experiment two independent sources of signal impairment from MRM chirp. Signal throughput can be as much as doubled when using a low-chirp design. This enables adoption of very small, low power, easily integrated SiP modulators for short-reach applications at very high throughput.