# JOKARUS - Design of a compact optical iodine frequency reference for a sounding rocket mission

## TL;DR

This paper details the design of a compact, space-qualified iodine-based optical frequency reference using integrated laser and spectroscopy components, scheduled for launch on a sounding rocket to validate its performance in space.

## Contribution

It introduces a novel, miniaturized iodine frequency reference system with integrated components for space applications, advancing the technology readiness level.

## Key findings

- Achieved fractional frequency instability better than 3×10⁻¹⁴
- Successfully integrated laser, amplifier, and spectroscopy modules in a compact setup
- Demonstrated autonomous operation suitable for space deployment

## Abstract

We present the design of a compact absolute optical frequency reference for space applications based on hyperfine transitions in molecular iodine with a targeted fractional frequency instability of better than $3\cdot 10^{-14}$. It is based on a micro-integrated extended cavity diode laser with integrated optical amplifier, fiber pigtailed second harmonic generation wave-guide modules, and a quasi-monolithic spectroscopy setup with operating electronics. The instrument described here is scheduled for launch end of 2017 aboard the TEXUS 54 sounding rocket as an important qualification step towards space application of iodine frequency references and related technologies. The payload will operate autonomously and its optical frequency will be compared to an optical frequency comb during its space flight.