Silicon Photonics Single-Sideband Modulator for Millimeter-Wave Band Wireless Systems

We propose a single-sideband modulator scheme realized in silicon on insulator technology operating in harmonic mode that allows extending the effective bandwidth of carrier-depletion-based silicon photonics modulators for the distribution of millimeter-wave signals in the radio access network. Using a device with a nominal −3 dB frequency response of less than 20GHz, photodetected broadband RF signals at 33 and 49.5GHz are demonstrated by driving the modulator with a 5Gbps ASK-modulated carrier at 16.5GHz. The scheme permits continuously tunable carrier-to-sideband ratio and large suppression of spurious sidebands in excess 30dB, and presents a compact layout comprising a single phase modulator and a photonic integrated filter. BER measurements confirm negligible chirp-induced effects of modulated sideband filtering after fiber transmission.