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arXiv · 2406.13159

Ultrastable vacuum-gap Fabry-P\'erot cavities operated in air

Yifan Liu·Naijun Jin·Dahyeon Lee·Charles McLemore·Takuma Nakamura·Megan Kelleher·Haotian Cheng·Susan Schima·Nazanin Hoghooghi·Scott Diddams·Peter Rakich·Franklyn Quinlan
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Abstract

We demonstrate a vacuum-gap ultrastable optical reference cavity that does not require a vacuum enclosure. Our simple method of optical contact bonding in a vacuum environment allows for cavity operation in air while maintaining vacuum between the cavity mirrors. Vacuum is maintained long term, with no observed degradation in cavity stability for over 1 year after bonding. For a 1550 nm laser stabilized to a 9.7 mL in-vacuum bonded cavity, the measured Allan deviation is $2.4\times 10^{-14}$ at 1 s and its phase noise is thermal-noise-limited from 0.1 Hz to 10 kHz, reaching about -105 dBc/Hz at 10 kHz offset frequency. This represents the highest stability of any oscillator operated without a vacuum enclosure. Furthermore, we demonstrate a 0.5 mL in-vacuum bonded cavity created using microfabricated mirrors and cavity dicing, with phase noise reaching -95 dBc/Hz at 10 kHz offset frequency. By relieving the need for high-vacuum enclosures, we greatly enhance the portability and utility of low noise, compact cavity-stabilized lasers, with applications ranging from environmental sensing to mobile optical clocks to ultralow noise microwave generation.

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Yifan Liu, Naijun Jin, Dahyeon Lee, Charles McLemore, Takuma Nakamura, Megan Kelleher, Haotian Cheng, Susan Schima, Nazanin Hoghooghi, Scott Diddams, Peter Rakich, Franklyn Quinlan. 2024-06-19. Ultrastable vacuum-gap Fabry-P\'erot cavities operated in air. https://arxiv.org/abs/2406.13159

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