Transmittance signal in real ladder-type atoms

Abstract

We clarify an interpretation of transmittance signals in ladder-type atomic systems by discriminating the contributions of one-photon resonance, two-photon resonance, and a mixed term of both in the calculated spectra for these ladder-type multilevel atoms. When the two-photon-resonance effect is distinguished from an accurate spectrum calculated by modeling ladder-type electromagnetically-induced transparency for the 5S 1/2 − 5P 3/2 − 5D 5/2 transitions of 87 Rb atoms, we find that the transmittance signals for the 5D 5/2 (F = 2,3) states are mainly composed of the mixed term related not to pure-two-photon atomic coherence but to the optical-pumping effect whereas the transmittance signal for the 5D 5/2 (F = 4) state originates from both the pure-two-photon-resonance term and the mixed term.

Comparison between transparencies of 5S_1/2-5P_3/2-4D_5/2 and 5S_1/2-5P_3/2-5D_5/2 transitions of ^87Rb atoms

“…To investigate the causes of the transparencies in the 5S 1∕2 -5P 3∕2 -4D 5∕2 and 5S 1∕2 -5P 3∕2 -5D 5∕2 transitions, we calculated the density matrix equation considering all the degenerate magnetic sublevels of the hyperfine states of the included fine-structure states [21]. In addition, to consider the Dopplerbroadened atomic medium, the numerically calculated spectra were averaged over the Maxwell-Boltzmann velocity distribution.…”

Tunable high-order photonic band gaps of ultraviolet light in cold atoms

“…We first consider the case in which levels |1 , |2 , |3 , |4 , and |5 correspond, respectively, to |F = 2,m F = 2 of 5S 1/2 , |F = 1,m F = 0 of 5S 1/2 , |F = 2,m F = 1 of 5P 1/2 , |m J + m I = 2 of 7S 1/2 , and |m J + m I = 3 of 15P 3/2 for cold 87 Rb atoms in the presence of a moderate magnetic field [30][31][32]. In this case, all the applied fields should have an exact σ + polarization and we can choose the dressing field of wavelength λ d 1501 nm (infrared) to work in the SW configuration.…”

“…(b) Reflectivity (black solid) and transmissivity (blue dashed) vs probe detuning p with d+ = 168 MHz, d− = 143 MHz, c = 4.0 MHz, a = 60 MHz, d = = 0,γ 21 = 0.2 kHz, γ 31 = 5.8 MHz, γ 41 = 0.6 MHz, γ 51 = 0.2 MHz, θ d = 7.78 • , d 15 = 1.6 × 10 −30 C m, N 0 = 8.0 × 10 12 cm −3 , and L = 9.8 mm. Relevant field wavelengths are λ p = 303 nm, λ d = 1501 nm, λ c = 728 nm, and λ a = 795 nm[30][31][32].…”

Active narrowband filtering, line narrowing and gain using ladder electromagnetically induced transparency in an optically thick atomic vapour

“…The combination of line narrowing and gain results in a tunable narrowband filter with contrast (the amount of probe transmission, relative to the input probe intensity) of 100% and a transparency width of order 15 MHz (FWHM). In addition, we show how density-induced line narrowing allows high resolution spectroscopy of the excited-state hyperfine structure [20] even in the presence of strong power broadening. The paper is arranged as follows: In Section 2 we describe the experimental setup.…”

“…Although this ladder system has been studied extensively in previous work [15][16][17][18][19][20][21], here we focus on novel effects that occur at high optical depths and high coupling laser Rabi frequency. In particular we show that the line narrowing effect due to high optical depth can be more efficient in a ladder-type system because, in contrast to the Λ-system studied previously [12], the coupling laser frequency is far detuned from the the ground-state transition and thus experiences much less absorption.…”