Stimulated Raman Adiabatic Passage in a Dense Medium

Figure 2

A reduced states formulation of STIRAP in azulene. Field 𝐄₂(𝑡) connects states 2 and 3 corresponding to 𝑆₁ with the excitation of one vibrational quantum, and the vibrationless state of 𝑆₂, respectively. State 1 represents the vibrationless state of a singlet 𝑆₀ and field 𝐄₁(𝑡) excites transition 1→2, so that the sum of frequencies 𝜔₁(𝑡)+𝜔₂(𝑡) is close to the frequency of purely electronic transition 𝑆₀→𝑆₂.