Patent ID: 11909171
Assignee: APPLE INC.
Field: Measurement (Instruments)
Classification: CPC H  G | IPC G  H

Claim 11:
12. An optical sensor system, comprising:
a semiconductor substrate;
a set of epitaxial layers formed on the substrate and defining,
a semiconductor laser having a resonant cavity parallel to the semiconductor substrate and parallel or orthogonal to a primary electromagnetic radiation emission axis of the semiconductor laser;
a first photodetector positioned adjacent a first end of the resonant cavity and configured to receive a secondary electromagnetic radiation emission of the semiconductor laser; and
a second photodetector positioned adjacent a second end of the resonant cavity and configured to receive a tertiary electromagnetic radiation emission of the semiconductor laser; and

a circuit configured to generate an SMI signal by combining a first photocurrent generated by the first photodetector and a second photocurrent generated by the second photodetector; wherein,
the first photocurrent and the second photocurrent have opposite SMI excess phases.