An optical sensor system including a semiconductor substrate; a self-mixing interferometry (SMI) sensor formed on the semiconductor substrate and including a semiconductor laser having a resonant cavity; and an array of photodetectors formed on the semiconductor substrate. The SMI sensor is configured to generate an SMI signal responsive to a retro-reflection of electromagnetic radiation emitted by the semiconductor laser and received into the resonant cavity. The array of photodetectors is configured to generate a set of angular-resolved scatter signals responsive to a scatter of the electromagnetic radiation emitted by the semiconductor laser.