Isotope shift measurement of the 423-nm transition in neutral Ca

TL;DR

This study precisely measures isotope shifts of the 423-nm transition in calcium, significantly improving accuracy and confirming linearity with other transitions through King plot analysis.

Contribution

The paper provides highly precise isotope shift measurements for calcium's 423-nm transition, enhancing previous data and validating linearity with other transitions via King plot analysis.

Findings

Isotope shifts measured with sub-100 kHz precision.

King plot analysis shows excellent linearity.

Field and mass shift parameters determined.

Abstract

We report on saturated absorption spectroscopy measurements of the $(4s^2) ^{1}S_0\rightarrow(4s4p) ^{1}P_1$ transition for the four most abundant even-mass isotopes in calcium. By referencing the laser locked to an ultralow expansion cavity and carefully investigating systematic errors, isotope shifts are determined with a precision below 100 kHz, improving previously reported values by a factor of about five. A King plot analysis employing literature values of the 729-nm transition in Ca ions shows excellent linearity. The field and mass shift parameters are determined from King plots with other transitions.