Overcoming the speckle correlation limit to achieve a fiber wavemeter with attometer resolution

TL;DR

This paper introduces a speckle pattern analysis method that surpasses traditional correlation limits, enabling a compact fiber-based wavemeter to achieve attometer wavelength resolution, significantly improving precision in optical measurements.

Contribution

The authors demonstrate a novel principal component analysis approach that overcomes speckle correlation limits, achieving unprecedented wavelength resolution in a fiber wavemeter.

Findings

Achieved 5.3 attometer wavelength resolution

Overcame speckle correlation limit using PCA

Demonstrated a compact, high-precision fiber wavemeter

Abstract

The measurement of the wavelength of light using speckle is a promising tool for the realization of compact and precise wavemeters and spectrometers. However, the resolution of these devices is limited by strong correlations between the speckle patterns produced by closely-spaced wavelengths. Here, we show how principal component analysis of speckle images provides a route to overcome this limit. Using this, we demonstrate a compact wavemeter which measures wavelength changes of a stabilized diode laser of 5.3 am, eight orders of magnitude below the speckle correlation limit.