Coherent spectroscopic methods with extended interrogation times and systems implementing such

摘要

Coherent spectroscopic methods are described, to measure the total phase difference during an extended interrogation interval between the signal delivered by a local oscillator (10) and that given by a quantum system (QS). According to one or more embodiments, the method may comprise reading out at the end of successive interrogation sub-intervals (T i ) intermediate error signals corresponding to the approximate phase difference (Õ) between the phase of the LO signal and that of the quantum system, using coherence preserving measurements; shifting at the end of each interrogation sub-intervals (T i ) the phase of the local oscillator signal, by a known correction value (Õ (i) FB ) so as to avoid that the phase difference approaches the limit of the inversion region; reading out a final phase difference (Õ f ) between the phase of the prestabilized oscillator signal and that of the quantum system using a precise measurement with no restriction on the destruction; reconstructing a total phase difference over the extended interrogation interval, as the sum of the final phase difference (Õ f ) and the opposite of all the applied phase corrections - ˆ‘ i Æ FB i .