# Stabilized microwave-frequency transfer using optical phase sensing and actuation

## TL;DR

This paper introduces a novel stabilized microwave-frequency transfer method using optical phase sensing and actuation, demonstrating high stability over long fiber links and potential application in radio astronomy.

## Contribution

The paper presents a new optical-based technique for microwave-frequency transfer that offers improved stability and is suitable for large-scale scientific applications.

## Key findings

- Achieved fractional frequency stability of 6.8x10^-14 at 1 s
- Demonstrated transfer over 166 km fiber network
- Potential application in SKA1-mid radio telescope

## Abstract

We present a stabilized microwave-frequency transfer technique that is based on optical phase-sensing and optical phase-actuation. This technique shares several attributes with optical-frequency transfer and therefore exhibits several advantages over other microwave-frequency transfer techniques. We demonstrated stabilized transfer of an 8,000 MHz microwave-frequency signal over a 166 km metropolitan optical fiber network, achieving a fractional frequency stability of 6.8x10^-14 Hz/Hz at 1 s integration, and 5.0x10^-16 Hz/Hz at 1.6x10^4 s. This technique is being considered for use on the Square Kilometre Array SKA1-mid radio telescope.

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Source: https://tomesphere.com/paper/1705.01169