Hollow-core fiber with stable propagation delay between-150 degrees C and+60 degrees C

Optical fibers with a low thermal coefficient of delay (TCD) have been developed for frequency and timing transmis-sion/distribution. However, their temperature sensitivity changes as a function of temperature and, to date, no study of such fibers has demonstrated improved performance over extended temperature ranges, especially at sub-zero temper-atures. Here, we show that a hollow core fiber (HCF) with a thin acrylate coating can have a TCD within +/- 2.0 ps/km/degrees C over a broad temperature range from -150 degrees C to +60 degrees C. In addition, this thinly coated HCF can be fully insensitive to temperature around -134 degrees C, making it of interest, e.g., for laser stabilization close to cryogenic temperatures.Published by Optica Publishing Group under the terms of the Cre-ative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published arti-cle's title, citation, and DOI.