The Nulling Interferometry Cryogenic Experiment (NICE): Architecture, requirements, and preliminary warm precursor results

TL;DR

The NICE project develops a cryogenic nulling interferometry testbed to advance exoplanet detection technology for the LIFE space mission, demonstrating key nulling performance in preliminary tests.

Contribution

This paper introduces the NICE architecture, requirements, and initial warm precursor results, advancing the technology readiness for high-contrast exoplanet spectroscopy.

Findings

Achieved null depth below 10^-5 with a narrowband 4.7 μm source.

Demonstrated throughput greater than 17% in the warm precursor.

Validated the optical design and laboratory requirements for LIFE's beam combiner.

Abstract

The success of the Large Interferometer For Exoplanets (LIFE) space mission depends on measuring the faint mid-infrared emission spectra of exoplanets while suppressing the glare of a host star. This requires an instrument capable of high-contrast nulling interferometry with exceptional sensitivity. While previous testbeds have proven the principle of deep, stable nulls, they have not combined high contrast with the high throughput and cryogenic operation required for LIFE. Here, we present the architecture of the Nulling Interferometry Cryogenic Experiment (NICE), a mid-infrared nulling testbed, to increase the technological readiness of LIFE. We derive the laboratory requirements necessary to validate the LIFE beam combiner and present the optical design of NICE. Finally, we report results from the ambient \enquote{Warm Bench} precursor, which has successfully demonstrated the required null depth ($< 10^{-5}$) using a polarized narrowband 4.7 um source, and the required throughput (> 17%) using one of the two nulling channels.