A NICE (Nulling Interferometry Cryogenic Experiment) update: Beyond 1e-5 and towards cryogenic operation

Abstract

The Nulling Interferometry Cryogenic Experiment (NICE) is a mid-infrared laboratory testbed at ETH Zürich that aims to not only reproduce the deep ($<1\times 10^{-5}$) broadband nulls of the nulling testbeds of the early 2000s, but also at the required sensitivity levels expected for the LIFE space mission. This sensitivity enforces the experiment to go cryogenic at temperatures around 15 K; an ambitious task for an ultra-precise interferometer. We share our results of the ambient precursor experiment, demonstrating repeatable $<1\times 10^{-5}$ nulls at a single wavelength and high throughput, and investigations into the nulling performance across a broader bandpass and with dual polarisation states. We will also highlight the push towards cryogenic operation, with the instalment of a new 15 K test cryostat that will inform our choices of materials and optomechanical mounting techniques.

15 pages, 7 figures; Submitted to the proceedings of Optical and Infrared Interferometry and Imaging X, SPIE Astronomical Telescopes + Instrumentation 2026. Paper No. 14148-26