Laser frequency stabilization to highly excited state transitions using electromagnetically induced transparency in a cascade system

TL;DR

This paper presents a method for laser frequency stabilization to excited state transitions using cascade electromagnetically induced transparency in a room temperature rubidium vapor cell, achieving a linewidth of 280 kHz.

Contribution

The authors demonstrate a novel technique for laser stabilization to highly excited states via cascade EIT, applicable without strong optical transitions.

Findings

Achieved laser linewidth of 280 kHz over 0.1 ms

Stabilized lasers to Rydberg states with n=19-70

Method applicable to various cascade systems

Abstract

We demonstrate laser frequency stabilization to excited state transitions using cascade electromagnetically induced transparency (EIT). Using a room temperature Rb vapor cell as a reference, we stabilize a first diode laser to the D2 transition and a second laser to a transition from the intermediate state to a Rydberg state with principal quantum number n=19 - 70. A combined laser linewidth of 280 kHz over a 0.1 ms time period is achieved. This method may be applied generally to any cascade system and allows laser stabilization to an atomic reference in the absence of strong optical transitions.