A compact, robust, and transportable ultra-stable laser with a fractional frequency instability of $1\times10^{-15}$

TL;DR

This paper reports a compact, robust, and transportable ultra-stable laser system achieving a fractional frequency instability of 1×10⁻¹⁵, suitable for satellite and terrestrial applications, with low vibration sensitivity and high stability.

Contribution

The authors developed a miniaturized, vibration-resistant ultra-stable laser prototype with low acceleration sensitivity, designed for space missions and terrestrial use, demonstrating exceptional frequency stability.

Findings

Achieved fractional frequency instability of 1×10⁻¹⁵ at 1-10 s

Designed dimensions are 40cm×20cm×30cm

Measured acceleration sensitivities are below 2×10⁻¹¹/g

Abstract

We present a compact and robust transportable ultra-stable laser system with minimum fractional frequency instability of $1\times10^{-15}$ at integration times between 1 to 10 s. The system was conceived as a prototype of a subsystem of a microwave-optical local oscillator to be used on the satellite mission STE-QUEST (Space-Time Explorer and QUantum Equivalence Principle Space Test, http://sci.esa.int/ste-quest/). It was therefore designed to be compact, to sustain accelerations occurring during rocket launch, to exhibit low vibration sensitivity, and to reach a low frequency instability. Overall dimensions of the optical system are $40\textrm{ cm}\times20\textrm{ cm}\times30\textrm{ cm}$. The acceleration sensitivities of the optical frequency in the three directions were measured to be $1.7\times10^{-11}/g$, $8.0\times10^{-11}/g$, and $3.9\times10^{-10}/g$, and the absolute frequency instability was determined via a three-cornered hat measurement. The design is also appropriate and useful for terrestrial applications.