We present an innovative concept for quantum-enhanced multiparameter optical
phase sensing that can be implemented in free space, optical fiber or on-chip.
Our measurable phases are in series, or cascaded, enabling measurements as a
function of position with only a single input and output. We have modeled up to
20 phases, and fitting shows near-linear scaling of the power requirements for
additional phases. This novel approach represents a new paradigm in
multiparameter quantum metrology, and can be applied to remote sensing,
communications, and geophysics.Comment: 5 pages, 4 figures. Comments are welcom