Interaction between single frequency two photon and one photon transitions in a V system

In this experimental work we address the issue of interaction between non-resonant two photon absorption (5S_1/2→ 5D_5/2) and a resonant one photon transition (5S_1/2→5P_3/2) in a Doppler broadened medium of hot Rubidium atoms under the V type coupling scheme 5D_5/2← 5S_1/2→5P_3/2. For a particular Rb isotope, suppression of one and two photon absorptions (sharing same ground state hyperfine component) are observed. At the same time increment in two photon absorption for the same isotope involving other ground state hyperfine component is noticed. The two photon transition is studied by monitoring the blue fluorescence emitted in 5D_5/2→6P_3/2→ 5S_1/2 spontaneous decay route. The recorded blue light is the measure of population in 5D state; thus indicating the relative strength of absorption. Transparency observed in this case is due to coupling field saturation and quantum interference. The even parity-odd parity (dipole forbidden–dipole allowed) V type linkage exhibits presence of coherent control under three level configuration. Our studies may find application in optical communication, negative energy study and indirectly to parity non-conservation experiments, where S→S transitions are used.