High-contrast coherent population trapping resonances using four-wave mixing in 87Rb.
We demonstrate very high-contrast coherent population trapping(1) (CPT) resonances by using four-wave mixing in (87)Rb atoms. In the experiment, we take advantage of the spectral overlap between F=2-->F(?) and F=3-->F(?) optical resonances on the D1 line of (87)Rb and (85)Rb atoms, respectively, to eliminate the DC-light background from the CPT resonance signal. We observe a CPT resonance with a contrast in the range of 90%, compared with a few percent achieved by alternative methods.
Shah
V
V
Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305, USA. vshah@boulder.nist.gov
Knappe
S
S
Hollberg
L
L
Kitching
J
J