Precision frequency measurements with interferometric weak values

TL;DR

This paper demonstrates a highly sensitive optical frequency measurement technique using a Sagnac interferometer and weak value amplification, achieving 129 kHz/√Hz sensitivity with low power, suitable for precision frequency measurements and laser locking.

Contribution

It introduces a novel interferometric weak value measurement method for high-precision frequency detection with low power input.

Findings

Achieved 129 kHz/√Hz frequency sensitivity

Demonstrated measurement of weak values in an optical interferometer

Potential for high-sensitivity frequency applications

Abstract

We demonstrate an experiment which utilizes a Sagnac interferometer to measure a change in optical frequency of 129 kHz per root Hz with only 2 mW of continuous wave, single mode input power. We describe the measurement of a weak value and show how even higher frequency sensitivities may be obtained over a bandwidth of several nanometers. This technique has many possible applications, such as precision relative frequency measurements and laser locking without the use of atomic lines.