Outlook and Plans for Phase-Squeezed Two-Photon Absorption Laser Induced Fluorescence

The ground state of hydrogen is known to be measurable by laser induced excitation of the Lyman beta transition by 205 nm light in a two-photon process. We investigate the feasibility of using squeezed light to enhance the absorption cross-section. The time correlation of the arriving photons is higher for photons in a phase-squeezed beam than for uncorrelated photons from a coherent laser source. This increases the chance of photons being absorbed together, which would increase any laser-induced fluorescence or absorption signals. Having shown the feasibility of generating squeezed light in this manner, a comparison of the absorption properties of squeezed and classical light can be made in a suitable plasma source, and the enhancement in cross-section from the use of squeezed light can be quantified. The results from this comparison will reveal the parameter space in which squeezed light enhancements can be used for two photon plasma diagnostics.