Crossover from electromagnetically induced transparency to Autler-Townes splitting in open V-type molecular systems

Abstract

We investigate electromagnetically induced transparency (EIT) and Autler-Townes splitting (ATS) in an open V-type molecular system. Through detailed analytical calculations on the absorption spectrum of probe laser field by using residue theorem and spectrum decomposition, we find that EIT may occur and there exists a crossover from EIT to ATS (i.e. EIT-ATS crossover) for hot molecules. However, there is no EIT and hence no EIT-ATS crossover for cold molecules. Furthermore, we prove that for hot molecules EIT is allowed even for a counter-propagating configuration.We provide explicit formulas of EIT conditions and widths of EIT transparency windows of probe field when hot molecules work in co-propagating and counter-propagating configurations, respectively. Our theoretical result agrees well with the recent experimental one reported by Lazoudis et al. [Phys. Rev. A 83, 063419 (2011)].In the present work, we develop an analytical approach on EIT and ATS in an open V-type molecular system. By detailed analytical calculations on the absorption spectrum of probe field using residue theorem and spectrum-decomposition method, we find that EIT is possible and there exists a crossover from EIT to ATS (i.e. EIT-ATS crossover) for hot molecules with Doppler broadening. In contrast, there is no EIT and hence no EIT-ATS crossover for cold molecules. We find also that for hot molecules EIT is allowed even for a counterpropagating configuration for probe and control fields. We provide explicit formulas of EIT conditions, widths of EIT transparency windows, and group velocities of probe field when hot molecules work in co-propagating and counter-propagating configurations, respectively.Our theoretical result agrees well with the recent experiment reported by Lazoudis et al. [9].Before proceeding, we notice that the spectrum-decomposition method was first proposed by Agarwal [14] for analyzing probe-field absorption in several typical three-level atomic systems, which can isolate the precise nature of quantum interference induced by a control field. However, Agarwal's method is valid only for strong control field. Lately, Anisimov and Kocharovskaya [15] considered absorption lineshape of Λ-type system in view of resonant poles, and successfully explained the nature of quantum destructive interference for weak control field. Recently, Abi-Salloum [16] distinguished EIT and ATS for similar atomic systems discussed in Ref. [14] by using the method in Ref. [15], but with this method one cannot obtain the quantum interference term for strong control field analytically. In a recent work, Anisimov et al. suggested a computational fitting technique to objectively discerning ATS from EIT [17] from experimental data. Very recently, an experimental investigation of the crossover between ATS and EIT was carried out by Giner et al. [18] by using the method proposed by Anisimov et al. [17] These works are significant, especially for clarifying the difference between EIT and ATS and some related concepts of quantum interference.From the works...

Tuneable complementary metamaterial structures based on graphene for single and multiple transparency windows

“…Although ATS and EIT share similar spectra lineshapes, and can be understood by a coupled two-oscillator system, even crossover could happen between EIT and ATS under some situations67, their origins are different8: in EIT the transparency window is a quantum destructive interference between the energy transferred from an initial state to a final state via different pathways, whereas in ATS it is due to the strong-coupling induced splitting of resonant modes. In the following, a system that has a transparency window but is not originated from EIT will be called an EIT-like system.…”

Phase-controlled optical switching and slow- and weak-light solitons in a coherent molecular system with permanent dipole moments

“…Shown in Fig. 4(a) is the probe is the probe absorption spectrum Im Kω as a function of ω∕γ 31 for Ω c ∕γ 31 5.05e iπ∕4 (solid line) and Ω c ∕γ 31 5.05 (dashed line). We see that the EIT transparency window closes completely when the phase of the control field θ c decreases from π∕4 to 0.…”

“…Although most studies on EIT are focused on atomic systems, in recent years there has been much investigation of EIT in molecular systems both theoretically and experimentally [21][22][23][24][25][26][27][28][29][30][31]. However, up to now less attention has been paid to the EIT in molecules with permanent dipole moments (PDMs).…”

“…(a) Im Kω as a function of ω∕γ31 for Ω c ∕γ 31 5.05e iπ∕4 (solid line) and Ω c ∕γ 31 5.05 (dashed line). (b) Output of probe pulse with τ 0 1.0 × 10 −8 s after passing through the molecular medium of length 4 cm.…”

2-Dimensional sub-atomic localization of Rb Rydberg atoms for SI traceable E-field metrology

“…By following the method discussed in [18], the dispersion relation K(ω) for the system can be written as…”