Patent attributes
Systems and methods for direct measurement of imbalanced optical paths using entangled photons are provided. A system includes an optical source for generating a pair of simultaneously produced photons. The system also includes first and second emitter/receivers that emit first and second photons in the pair of simultaneously produced photons towards a first and second remote reflector and receives the reflected first and second photons along first and second optical paths. Further, the system includes a mode combiner for combining the reflected first and second photons into first and second output ports. Moreover, the system includes photodetectors that detect photons from the first and second output ports. Also, the system includes a processor that measures a difference in time delay between the first and second optical paths based on a time difference of arrival of signals from the photodetectors.