Cancellation of light shifts in an N-resonance clock.
We demonstrate that first-order light shifts can be canceled for an all-optical, three-photon-absorption resonance (N-resonance) on the D1 transition of 87Rb. This light-shift cancellation facilitates improved frequency stability for an N-resonance clock. For example, by using a tabletop apparatus designed for N-resonance spectroscopy, we measured a short-term fractional frequency stability (Allan deviation) of approximately/= 1.5 x 10(-11) tao1/2 for observation times of 1 s < or = tao < or = 50 s. Further improvements in frequency stability should be possible with an apparatus designed as a dedicated N-resonance clock.
Harvard-Smithsonian Center for Astrophysics and Department of Physics, Harvard University, Cainbridge, Massachusetts 02138, USA. i.novikova@osa.org
Irina
I
Novikova
David E
DE
Phillips
Alexander S
AS
Zibrov
Ronald L
RL
Walsworth
Aleksei V
AV
Taichenachev
Valeriy I
VI
Yudin