Indium Phosphide Photonic Integrated Circuits for CO2 Lidar
Photonic integrated circuit (PIC) technology will enable a future of ubiquitous compact sensors. One application space that can be disrupted by PIC-enabled sensors is remote Earth-science sensing. A photonic integrated lidar satellite module would greatly reduce the size, weight, and power of science instruments, making data collection much more affordable and accessible. In this work, a PIC was designed, fabricated, and characterized for a CO2 integrated path differential absorption (IPDA) lidar system operating at 1572 nm. Key achievements include demonstration of a novel method for simultaneous definition of variable coupling coefficient laser mirror gratings, 60 dB SMSR DFB lasers, a novel implementation of a low residual amplitude modulation phase modulator design, and integration of most of the optical functions for a lidar system to meet the specifications defined by the IDPA CO2 lidar developed for a NASA mission.