Cryogenic optical beam steering for superconducting device calibration

TL;DR

This paper presents a cryogenic optical beam steering system using MEMS mirrors, enabling precise calibration of superconducting sensors across a broad wavelength range at sub-Kelvin temperatures, crucial for quantum and dark matter research.

Contribution

The paper introduces the first cryogenic MEMS-based optical calibration system capable of operating at sub-Kelvin temperatures with high positional accuracy.

Findings

Successfully tested at room temperature and 20 mK

Achieved beam steering over a 3cm x 3cm area with 100 μm precision

Operates across 180-2000 nm wavelength range

Abstract

We have developed a calibration system based on a micro-electromechanical systems (MEMS) mirror that is capable of delivering an optical beam over a wavelength range of 180 -- 2000 nm (0.62 -- 6.89 eV) in a sub-Kelvin environment. This portable, integrated system can steer the beam over a $\sim$3 cm $\times$ 3 cm area on the surface of any sensor with a precision of $\sim$100 $\mu$m, enabling characterization of device response as a function of position. This fills a critical need in the landscape of calibration tools for sub-Kelvin devices, including those used for dark matter detection and quantum computing. These communities have a shared goal of understanding the impact of ionizing radiation on device performance, which can be pursued with our system. This paper describes the design of the first-generation calibration system and the results from successfully testing its performance at room temperature and 20 mK.