High-Performance Imaging in a Dilution Refrigerator

Timo Eikelmann; Mara Brinkmann; Leonie Eggers; Tuncay Ulas; Donika Imeri; Konstantin Beck; Lasse Jens Irrgang; Sunil Kumar Mahato; Rikhav Shah; Ralf Riedinger

arXiv · 2510.07054

High-Performance Imaging in a Dilution Refrigerator

Timo Eikelmann·Mara Brinkmann·Leonie Eggers·Tuncay Ulas·Donika Imeri·Konstantin Beck·Lasse Jens Irrgang·Sunil Kumar Mahato·Rikhav Shah·Ralf Riedinger

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Abstract

Nanophotonic light-matter interfaces hold great promise for quantum technologies. Enhancing local electromagnetic fields, they enable highly efficient detectors, can help realize optically connected processors, or serve as quantum repeaters. In-situ fiber-coupling at sub-Kelvin temperatures, as required for test and development of new devices, proves challenging as suitable cryogenic microscopes are not readily available. Here, we report on a robust and versatile confocal imaging system integrated in a dilution refrigerator, enabling high-resolution visualization of nanophotonic structures on a transparent diamond substrate. Our imaging system achieves a resolution of 1.1 {\mu}m and a field-of-view of 2.5 mm. The system requires no movable parts at cryogenic temperatures and features a large working distance, thereby allowing optical and microwave probe access, as well as direct anchoring of temperature sensitive samples to a cold finger, needed for applications with high thermal load. This system will facilitate the development of scalable, integrated quantum optics technology, as required for research on large scale quantum networks.

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Timo Eikelmann, Mara Brinkmann, Leonie Eggers, Tuncay Ulas, Donika Imeri, Konstantin Beck, Lasse Jens Irrgang, Sunil Kumar Mahato, Rikhav Shah, Ralf Riedinger. 2025-10-08. High-Performance Imaging in a Dilution Refrigerator. https://arxiv.org/abs/2510.07054

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