Crystalline Supermirrors for Infrared Applications

Activity: Talks and presentationsTalk or oral contributionScience to Science


High-performance supermirrors are employed in a variety of applications in optics and photonics: They are a key element for stable optical cavities, which are routinely used to narrow the linewidth of continuous-wave lasers, thereby creating optical references for frequency comb stabilization and precision spectroscopy. Furthermore, they are a vital component for optical interferometers, which enable scientific discovery in fields as seemingly unrelated as microcavity sensing and gravitational wave detection.

Especially at mid-infrared wavelengths, emerging applications in chemical sensing, discrete imaging, ultracold chemistry, and even fundamental physics will benefit immediately from high-performance mirrors. Therefore, the development of low-loss mirrors in this wavelength range is a long-standing goal. However, traditional techniques for the fabrication of high-reflectivity mirrors fail to match the performance readily accessible in the visible and near-infrared wavelength range.

In recent years, substrate-transferred monocrystalline supermirrors have emerged as a promising technology to overcome these limitations. Originally developed as a means to overcome the Brownian-noise limit in precision near-infrared interferometry, crystalline mirrors also exhibit extremely low absorption and scatter losses over their entire transparency window (0.87 µm to 10 µm). This enables supermirror-level reflectivity at mid-infrared wavelengths.

In this talk we will take a look at the key features and wide range of applications of these crystalline Bragg reflector mirrors. Building on this framework, I will also present our achievements in precision characterization and design improvements, including the recent demonstration of unprecedentedly high-reflectivity mirrors at 4.45 µm and a cavity Finesse in excess of 400 000.
Period26 Jan 2024
Event titleUSQS - International Conference on Ultradast Science and Quantum Sensing
Event typeConference
LocationSanya, ChinaShow on map
Degree of RecognitionInternational