Accurate absolute frequency measurements across the optical spectrum using a single ion

Abstract

A 445-THz (674nm), 88Sr+ trapped and laser cooled single ion reference transition has been used at the National Research Council of Canada (NRC) to extend precision frequency measurements to other points in the electromagnetic (EM) spectrum. We are currently refining the single ion experiment to approach the uncertainty limited spectral resolution of 1×10-15. Connected with these developments is the use of frequency grids based on mode-locked femtosecond lasers. A band of reference modes extending from 520 nm to beyond 1060 nm has been recently obtained femtosecond lasers. A band of reference modes extending from 520 nm to beyond 1060 nm has been recently obtained at NRC and has been applied to the absolute frequency measurement of the widely used 633 nm I2 stabilized HeNe laser standard. Excellent agreement was obtained between the measurements determiend via ion an comb based measurements. With such devices, the possibility of accurate, stable and compact sources at any wavelength is coming into being.