Speaker
Description
To achieve high rates of entanglement generation in trapped ion quantum networks [1], the Purcell enhancement offered by optical cavities can be used to reach near-unit photon collection efficiency [2]. In this work, we address the challenges of fabricating and characterizing microcavity mirrors with ultralow, Å-level roughness, necessary to achieve high cooperativity in ion-cavity systems. We use focused ion beam (FIB) milling to produce features with state-of-the-art surface roughness for this size and scale [3,4]. To rapidly characterize these mirrors and to drive iterative improvements of the fabrication methods used, we design and build an automated cavity mode-matching experiment. An algorithm controls the degrees of freedom of a multi-axis stage (hexapod), on which the cavity is mounted. Using this method, we can achieve dominant coupling to the fundamental within the span of minutes, for a wide range of initial misalignments, and obtain the cavity finesse through automated measurements. These fabrication and characterisation developments offer a repeatable and scalable route to realising high finesse microcavities suitable for integration into ion trap network nodes.
- L.J. Stephenson, et al., Phys. Rev. Lett. 124, 110501 (2020).
- J. Schupp, PRX Quantum 2, 020331 (2021).
- P. Maier, Opt. Express 33, 19205-19219 (2025).
- A.A.P. Trichet et al., Opt. Express 13 17205-17216 (2015).
| Academic level | PhD student |
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