Hyperfine measurement of the 6P1/2 state in 87Rb using double resonance on blue and IR transition

In this paper, we present the spectroscopy of the 6P(1/2) state in Rb-87 using a double-resonance technique at 780 nm and 421 nm. The double-resonance technique is implemented using electromagnetically induced transparency (EIT) and optical pumping methods. Using these spectroscopy methods, we have measured the hyperfine splitting of the 6P(1/2) state with precision of <400 kHz, which agrees well with other spectroscopy methods such as electrical discharge and saturated absorption spectroscopy at 421 nm.