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Non-contact control of two-photon absorption
Applied Optics
|November 2, 2017
Summary
This study demonstrates control over two-photon absorption in Rubidium-85 (Rb85) atoms using an auxiliary laser beam. This method manipulates atomic population asymmetry to enhance or suppress two-photon absorption.
Area of Science:
- Atomic physics
- Quantum optics
- Laser spectroscopy
Background:
- Two-photon absorption (TPA) is a nonlinear optical process relevant in various applications.
- Controlling TPA is crucial for optimizing these applications.
- Doppler broadening in atomic media complicates TPA control.
Purpose of the Study:
- To investigate a novel method for controlling TPA in Doppler-broadened Rb85 atoms.
- To demonstrate the suppression and enhancement of TPA using an auxiliary laser beam.
- To elucidate the physical mechanism behind this TPA control.
Main Methods:
- Experimental setup involving a ladder-type atomic transition (5S1/2→5P3/2→5D3/2) in Rb85.
- Utilizing a pump-probe laser configuration for TPA.
- Employing an off-axis resonant auxiliary laser beam to induce population asymmetry.
Main Results:
- The auxiliary laser beam successfully controlled TPA.
- Suppression and enhancement of TPA were achieved by manipulating ground state hyperfine population asymmetry.
- The spatial separation of the auxiliary beam from the pump-probe path was key.
Conclusions:
- An auxiliary laser beam can effectively control two-photon absorption in Rb85.
- Population asymmetry in ground state hyperfine components is the underlying control mechanism.
- This technique offers a new pathway for manipulating nonlinear optical processes in atomic systems.
