A 106.25 Gb/s 2ASK-DBPSK Integrated Silicon Self-Coherent Optical Receiver

This paper presents a 106.25 Gb/s two amplitudeshift keying differential binary phase-shift keying (2ASK-DBPSK) co-integrated self-coherent optical receiver consisting of a silicon photonic integrated circuit (PIC) and an electrical integrated circuit (EIC). The optical receiver detects the phase information of the optical signal using a delay line interferometer (DLI) on the PIC. Without any equalization, a sensitivity of -7.3 dBm at a bit-error rate (BER) of 3.8 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup> was measured. Using a 9-tap feed-forward equalizer (FFE, implemented offline) a sensitivity of -7.2 dBm at a BER of 2.4 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−4</sup> was measured. Unlike 4-level pulse amplitude modulation (PAM-4), the approach does not necessarily need linear electronics. In addition, no local oscillator laser is required at the receiver to detect the optical phase information.