ORCID ID
https://orcid.org/0000-0002-7779-9741
Date Awarded
2020
Document Type
Dissertation
Degree Name
Doctor of Philosophy (Ph.D.)
Department
Physics
Advisor
Irina B Novikova
Committee Member
Eugeniy E Mikhailov
Committee Member
William Cooke
Committee Member
Todd Averett
Committee Member
Ryan T Glasser
Abstract
Multi-photon nonlinear processes in atoms have served as important tools for quantum metrology, quantum communications, and quantum sensing. In this thesis, we experimentally address the interplay of various multi-photon Raman processes in hot Rb vapor, with the four-wave mixing (FWM) process being a central theme. FWM is the nonlinear response of a medium to a strong optical pump field inelastically scattering off atomic resonances and resulting in the generation of additional photons in different modes. FWM is a detrimental, but inherent part of electromagnetically induced transparency (EIT) and Raman based quantum memories. However, we were able to weaken the four-photon resonance by utilizing two-photon absorption to remove the additional photons without interfering with the signal beam. We also demonstrate the ability to tailor FWM to generate new photons in a controlled fashion for mode conversion. With this, we showed the conversion of 795 nm light to 420 nm light. While FWM is a source of noise in quantum memories, it can also be used for the generation squeezed twin-beams. Such beams have relative intensity noise reduced below the classical shot noise limit and share mode dependence based on the phase-matching conditions. Using this, we demonstrated that twin-beams can be generated with largely different spatial structure (optical angular momentum) and still share strong correlations, so long as the phase-matching conditions are satisfied. We then constructed and demonstrated the operation of a polarization-based quantum interferometer using squeezed twin-beams and showed that our beams were entangled under the inseparability condition. Using this interferometer, we were also able to achieve squeezing at low detection frequencies, which is necessary for things like quantum imaging and gravitational wave detection. We also demonstrated that squeezed twin-beams can be utilized to enhance the sensitivity of two-photon absorption spectroscopy. This research has touched on many different subjects related to quantum information science and improved upon some of the tools needed for the implementation of such technologies.
DOI
http://dx.doi.org/10.21220/s2-93cy-dq98
Rights
© The Author
Recommended Citation
Prajapati, Nikunjkumar, "Development Of Quantum Information Tools Based On Multi-Photon Raman Processes In Rb Vapor" (2020). Dissertations, Theses, and Masters Projects. William & Mary. Paper 1616444554.
http://dx.doi.org/10.21220/s2-93cy-dq98