Citation:
Grant M. Brodnik, Harrington, Mark W. , Dallyn, John H. , Bose, Debapam , Zhang, Wei , Stern, Liron , Morton, Paul A. , Behunin, Ryan O. , Papp, Scott B. , and Blumenthal, Daniel J. . 2021.
“Optically Synchronized Fibre Links Using Spectrally Pure Chip-Scale Lasers”. Nature Photonics, 15, 8, Pp. 588 - 593.
https://doi.org/10.1038/s41566-021-00831-w.
Abstract:
Precision optical-frequency and phase synchronization over fibre is critical for a variety of applications, from timekeeping to quantum optics. Such applications utilize ultra-coherent sources based on stabilized table-top laser systems. Chip-scale versions of these systems may dramatically broaden the application landscape by reducing the cost, size and power of such exquisite sources. Links based on the required narrow-linewidth integrated lasers, compact reference cavities and control methodologies have not yet been presented. Here, we demonstrate an optically synchronized link that achieves an ultralow residual phase error variance of 3 × 10−4 rad2 at the receiver, using chip-scale stabilized lasers with laser linewidth of ~30 Hz and instability below 2 × 10−13 at 50 ms. This performance is made possible with integrated Brillouin lasers, compact reference cavities and a novel low-bandwidth optical-frequency-stabilized phase-locked loop. These results demonstrate a path towards low-power, precision applications including distributed atomic clocks, quantum links, database synchronization and digital-signal-processor-free coherent fibre interconnects.
