This paper presents a new method for fabricating high-finesse microcavities using buckled dielectric membrane mirrors. The approach achieves a record finesse of 0.9 million at 780 nm, enabling flexible device geometries, including singular mirrors and mirror arrays. These cavities have low surface roughness, making them suitable for applications in both classical and quantum photonics.
The study introduces a novel fabrication process based on standard microfabrication techniques. It starts with a polished silicon wafer, followed by dielectric coating using ion beam sputtering to create ultra-smooth surfaces. The mirrors naturally buckle due to built-in compressive strain in the dielectric coating. The paper details the fabrication steps, from surface smoothing to mirror shaping, and emphasizes the high uniformity and yield of the process.
The resulting microcavities are characterized by high finesse and quality factors. The cavity length, resonance frequency, and free spectral range (FSR) are precisely measured using swept-ring-down spectroscopy. Finesse values as high as 0.9 million and quality factors up to 2.3 billion are demonstrated. These cavities are further assembled into microcavity systems for potential use in quantum networking, laser stabilization, and high-efficiency filtering.
The study's key contribution is its simple, robust, and scalable method to produce state-of-the-art microcavities, which can be integrated into existing photonic architectures, particularly for quantum and classical applications. The small size of the cavities, combined with their high performance, makes them ideal for integration with systems involving neutral atoms and ion traps.
OMeda (Shanghai Omedasemi Co.,Ltd) was founded in 2021 by 3 doctors with more than 10 years of experience in nanpfabrication. It currently has 15 employees and has rich experience in nanofabrication (coating, lithography, etching, two-photon printing, bonding) and other processes. We support nanofabrication of 4/6/8-inch wafers.