Lifetime measurements of the5dstates of rubidium

Abstract

We present lifetime measurements of the 5D 3/2 and 5D 5/2 states of rubidium using the time correlated single photon counting method. We perform the experiment in a magneto-optical trap of 87 Rb atoms using a two-step excitation with the trap laser at 780 nm as the first step. We record the 761.9 nm fluorescence from the decay of the 5D 3/2 state to the 5P 1/2 state, and measure the lifetime of the 5D 3/2 state τ = 246.3(1.6) ns. We record the 420.2 nm fluorescence from the cascade decay of the 5D 5/2 state to the 5S 1/2 state through the 6P 3/2 state, and extract the lifetime of the 5D 5/2 state τ = 238.5(2.3) ns.

Subnatural linewidths in two-photon excited-state spectroscopy

“…Spectroscopy of excited state transitions is of growing interest for a variety of applications including the search for stable frequency references [1,2], state lifetime measurement [3], optical filtering [4], frequency up-conversion [5], multiphoton laser cooling [6], as well as Rydberg gases [7,8] and their application to electro-optics [9][10][11] and nonlinear optics [12]. Twophoton excited state spectroscopy can be achieved without significant transfer of population out of the ground state using electromagnetically induced transparency (EIT) [13] in the ladder configuration [14].…”

Anomalous two-photon spectral features in warm rubidium vapor

“…Excitation into the 5D 5/2 excited state was monitored using the 420-nm fluorescence produced when the excited state decays though the 6P 3/2 →5S 1/2 transition. Only 7.5% of the population excited into the 5D 5/2 excited state generates 420-nm fluorescence through this pathway [33]. Decay from the excited state will return the atom to one of the two ground states as depicted in Fig.…”

“…1(a). The 5D 5/2 excited state has a lifetime of 238 ns (linewidth of 666 kHz) [33]. The two-photon transition strength is enhanced by driving it with two different color lasers at 780 and 776 nm, which delivers a near-resonant intermediate state: the intermediate state, 5P 3/2 , has a lifetime of 26.2 ns (linewidth of 6.1 MHz) [34].…”

“…1 incorporated with known branching ratios [33,34,[38][39][40]. Figure 8 shows numerical simulations of P e ( ie , gi ) averaged over a Gaussian distribution of velocities and integrated over an average beam crossing time, when gi,± = i and ie,+ = i /10.…”

Two-color rubidium fiber frequency standard

“…This transition can be excited in a Doppler-free configuration [8], resulting in a linewidth of 334 kHz, limited by the natural lifetime [9] of the 5 D 5∕2 state. These standards use a single 778 nm laser tuned to half the energy difference between the 5 S 1∕2 and 5 D 5∕2 states.…”