Electromagnetically induced transparency in a six-level inverted-Y type atomic system using Rydberg state

The absorption features of a probe field propagating through a six-level inverted-Y type atomic system in presence of two additional coherent fields are investigated under both Doppler-free and Doppler-broadened conditions resembling the 87Rb 5S1⁄2 → 5P3⁄2 → 44D5⁄2 (Tr-I) through numerical simulation. A comparative study in the probe absorption is also made with the 87Rb 5S1⁄2 → 5P3⁄2 → 7S1⁄2 transition (Tr-II). Under thermal averaging five velocity selective optically pumped absorption peaks (VSOPAP) appear for both the transitions (Tr-I and Tr-II). An interesting feature noticed in the simulated absorption profile is that under thermal averaging we get two extra electromagnetically induced transparency (EIT) dips for Tr-I compared to Tr-II where only two EIT dips are noticed.