Title: Temperature-compensated ultra-stable optical cavity with re-entrant design
Abstract: Ultra-stable optical cavities with adjustable zero-crossing temperatures feature low thermal expansion and low temperature control power consumption. We develop a re-entrant cavity featuring flexible and nondestructive zerocrossing temperature tuning capabilities, with a tunable range of 49°C. Using the same ultra-low expansion glass (ULE) batch with a zero-crossing temperature of 16.0(4)°C, we experimentally demonstrate a re-entrant cavity with a higher zero-crossing temperature tuning to 24.7(4)°C, significantly increasing the operational range compared to traditional sandwich cavities. The ultra-stable laser system developed on this re-entrant cavity shows a thermal noise limited performance of 1.05(1)×10−15 at 0.2 s and a good long-term performance, making it suitable for portable applications such as space-borne laser sources.
Cite: J. Chang, Q. Wu, Z. Wang, J. Zhang, Q. Wei, X. Chen, Z. Lu, and J. Zhang, Temperature-compensated ultra-stable optical cavity with re-entrant design, Optics Letters 50, 868-871 (2025).
