Ultrasensitive Measurement of Angular Rotations via Hermite-Gaussian Pointer

TL;DR

This paper introduces a method using Hermite-Gaussian beams in weak measurement schemes to significantly enhance the sensitivity of angular rotation measurements, achieving sub-microradian precision.

Contribution

The work demonstrates a novel application of Hermite-Gaussian modes in weak measurement for ultrasensitive angular rotation detection, with both theoretical and experimental validation.

Findings

Precision improved by a factor of 2mn+m+n

Experimental detection of sub-microradian rotations

Enhanced sensitivity with HG55 mode over HG11 mode

Abstract

Exploring high sensitivity on the measurement of angular rotations is an outstanding challenge in optics and metrology. In this work, we employ the mn-order Hermite-Gaussian beam in the weak measurement scheme with an angular rotation interaction, where the rotation information is taken by another HG mode state completely after the post-selection. By taking a projective measurement on the final light beam, the precision of angular rotation is improved by a factor of 2mn+m+n. For verification, we perform an optical experiment where the minimum detectable angular rotation improves $\sqrt{15}$-fold with HG55 mode over that of HG11 mode, and achieves a sub-microradian scale of the measurement precision. Our theoretical framework and experimental results not only provide a more practical and convenient scheme for ultrasensitive measurement of angular rotations, but also contribute to a wide range of applications in quantum metrology.