Fig. 2: Experimental configuration.
From: Silicon photonic microresonator-based high-resolution line-by-line pulse shaping
High-level schematic diagram of experimental setups for a-i Multi-Heterodyne Spectroscopy (MHS), a-ii Dual-Comb Spectroscopy (DHS), for measuring the channel frequencies and phases, respectively, and a-iii the Waveform Monitor. Yellow and dashed black lines indicate optical and RF connections, respectively. Brown (solid and dashed) and green arrows in (a-i) follow directions of propagation for the MLFC and CW laser, respectively. Orange arrows in (a-ii) follow the signal comb. Arrows on the resonators within the SiP shaper follow the direction of propagation for each method. For clarity, the SiP shaper is drawn here with optical I/O on both sides of the chip; in the experiment, optical I/O is on a single side, as depicted in Fig. 1a. MHS and DCS measurements are run at the same time by adding circulators and DWDM filters. PD: Photodiode. b Flowchart of our shaper control scheme. c-i Transmission spectrum of the as-fabricated spectral shaper and c-ii with the shaper programmed to compress six lines from a 3 GHz EO comb. In both cases, the measurement is from a swept laser source and the two FSRs for MHS and DCS measurement are shown. Transmission is normalized to coupling loss to/from the chip, which we measure to be ~3.5 dB/facet.
