Thermal-noise Limits to the Frequency Stability of Burned Spectral Holes

TL;DR

This paper investigates the fundamental thermal-noise limits affecting the frequency stability of spectral holes burned in Eu3+:Y2SiO5, providing estimates to guide future experimental designs at cryogenic temperatures.

Contribution

It offers the first detailed analysis of thermal-noise limits in spectral-hole burning systems, including numerical estimates for Eu3+:Y2SiO5 at cryogenic temperatures.

Findings

Thermal noise sets a fundamental limit to spectral-hole frequency stability.

Numerical estimates for Eu3+:Y2SiO5 show potential stability at cryogenic temperatures.

Guidelines for future spectral-hole burning experiments are provided.

Abstract

Techniques in frequency stabilization of lasers to fixed-spacer optical cavities have advanced to the point where the ultimate frequency stabilities are limited by thermal noise in the cavity materials for standard cavity configurations at room temperature. The use of spectral-hole burning (SHB) in laser stabilization has produced promising results in early experiments. In this letter we explore the thermal-noise limits to frequency stability in burned spectral holes. We compile known material parameters for a typical system used in SHB experiments (Eu 3+ doped Y 2 SiO 5 ) to make numerical estimates for the fundamental thermal-noise induced frequency instability in spectral-holes for the liquid-helium temperature and dilution temperature cases. These efforts can guide the design of future SHB experiments and clarify which important material parameters remain to be measured.