Measurement Of Magic Wavelengths For The Ca-40(+) Clock Transition

We demonstrate experimentally the existence of magic wavelengths and determine the ratio of oscillator strengths for a single trapped ion. For the first time, two magic wavelengths near 396 nm for the Ca-40(+) clock transition are measured simultaneously with high precision. By tuning the applied laser to an intermediate wavelength between transitions 4s(1/2) -> 4p(1/2) and 4s(1/2) -> 4p(3/2), the sensitivity of the clock transition Stark shift to the oscillator strengths is greatly enhanced. Furthermore, with the measured magic wavelengths, we determine the ratio of the oscillator strengths with a deviation of less than 0.5%. Our experimental method may be applied to measure magic wavelengths for other ion clock transitions. Promisingly, the measurement of these magic wavelengths paves the way to building all-optical trapped ion clocks.