Measuring ultrasmall time delays of light by joint weak measurements

TL;DR

This paper introduces a method using joint weak measurements outside the weak-value amplification regime to precisely measure tiny light time delays, offering robustness against noise and broad applicability beyond phase shifts.

Contribution

It presents a novel measurement scheme that surpasses traditional limits by avoiding weak-value amplification, enabling more accurate detection of ultrasmall effects.

Findings

Robustness to noise enhances measurement precision.

Method surpasses standard interferometry in sensitivity.

Applicable to various small effect measurements.

Abstract

We propose to use weak measurements away from the weak-value amplification regime to carry out precision measurements of time delays of light. Our scheme is robust to several sources of noise that are shown to only limit the relative precision of the measurement. Thus, they do not set a limit on the smallest measurable phase shift contrary to standard interferometry and weak-value based measurement techniques. Our idea is not restricted to phase-shift measurements and could be used to measure other small effects using a similar protocol.