Collimated UV light generation by two-photon excitation to a Rydberg state in Rb vapor

Abstract

We use two continuous-wave (CW) laser beams of 780 nm and 515 nm to optically drive ${}^{85}$Rb atoms in a heated vapor cell to a low-lying Rydberg state 10D${}_{5/2}$. We observe a collimated ultraviolet (UV) beam at 311 nm, corresponding to the transition frequency from the 11P${}_{3/2}$ state to the 5S${}_{1/2}$ state. This indicates the presence of a coherent four-wave mixing process, built up by two input laser fields as well as a terahertz (THz) radiation of 3.28 THz that is generated by amplified spontaneous emission between the 10D${}_{5/2}$ and the 11P${}_{3/2}$ states. We characterize the 311 nm UV light generation and its dependence on various physical parameters. This scheme could open up a new possibility for generating narrow-band THz waves as well as deep UV radiation.

References in corpus (4)

• Quasiclassical calculations of BBR-induced depopulation rates and effective lifetimes of Rydberg nS, nP and nD alkali-metal atoms with n < 80
• Trans-spectral orbital angular momentum transfer via four wave mixing in Rb vapor
• Laser frequency stabilization to highly excited state transitions using electromagnetically induced transparency in a cascade system
• Coherent 455nm beam production in cesium vapor

Cited by in corpus (2)

• Directional THz generation in hot Rb vapor excited to a Rydberg state
• Spiking dynamics of frequency up-converted field generated in continuous-wave excited rubidium vapours