Quantum Reference Beacon

A method includes applying, to a sample exhibiting optical scattering and having a emission particles distributed therein that exhibit spin-dependent fluorescence, a magnetic field to shift a resonance frequency of each emission particle in a position-dependent manner. The method also includes exciting the sample with an excitation beam that causes at least one emission particle to emit spin-dependent fluorescence and detecting the emitted spin-dependent fluorescence. The method also includes estimating a position of the emission particle(s) within the sample based on the spin-dependent fluorescence, the resonance frequency, and the magnetic field. The method also includes estimating optical transmission information for the sample based on a wavefront of the excitation beam and the estimated position. The optical transmission information including a measure of an optical field at each position of an emission particle.