Non-contact control of two-photon absorption

Abstract

In this experimental work, we address the issue of the control of two-photon absorption in a Doppler broadened medium of Rb85 atoms under the ladder level coupling 5S→5P→5D. Here, suppression and enhancement of two-photon absorption are executed by applying an auxiliary laser beam, which is not physically propagating in the same line of the pump-probe combination. Instead, the auxiliary beam, which is in resonance with the Rb85 D transition, is at a finite distance from the line of propagation of the pump-probe combination. The resonant auxiliary beam produces an atomic beam in the vapor cell, and when it reaches the pump-probe path, it creates an asymmetry in the population of ground state hyperfine components. This asymmetry is responsible for controlling two-photon absorption. We present here results obtained by us along with a qualitative explanation of the physical principles behind the control mechanism.

Two‐Photon‐Excited Silica and Organosilica Nanoparticles for Spatiotemporal Cancer Treatment

“…Two‐photon absorption is a property of nonlinear optics . In this process, two photons of the same energy (though not always) produce an energy equal to the sum of the energies of the two photons ( Figure ) .…”

Diffraction and quantum control of wave functions in nonresonant two-photon absorption

“…This idea of quantum coherent control originated from molecular processes [8] has been extended to atomic systems [9,10], semiconductors [11], and nanoplasmonic structures [12] etc. Although the TPA has been studied for a long time, it still attracts considerable attention [13][14][15] until now because of its broad application prospects.…”