Measurement of two independent phase-shifts using coupled parametric amplifiers

TL;DR

This paper introduces a novel scheme using coupled parametric amplifiers in atomic media to simultaneously measure two independent phase-shifts in interferometers with a single detector, enhancing measurement efficiency and communication capacity.

Contribution

The paper presents a new method for two-phase measurement using dark-state-enhanced coupled parametric amplifiers to encode and decouple phase information in a single spectral measurement.

Findings

Successfully measures two phase-shifts simultaneously

Uses spectral waveform encoding in atomic media

Potential to increase optical communication channel capacity

Abstract

In this article, we demonstrate a scheme capable of two-phase measurement, i.e. the simultaneous measurement of the two phase-shifts occurring in two independent Mach-Zehnder interferometers using one intensity detector. Our scheme utilizes dark-state-enhanced coupled parametric amplifiers in an atomic medium to mix the multiple fields probing the various arms of the interferometers in parallel. The two phase-differences are then encoded in separate continuous-variable parameters in the spectral waveform of the parametrically amplified atom-radiated signal field, which can be directly decoupled in a single intensity measurement. Besides resolving two phase differences in parallel, this method can also be used to increase the channel capacity in optical and quantum communication by the simultaneous use of phase-modulation and amplitude-modulation.