Method of Power Recycling in Co-Axial Mach Zender Interferometers for Low Noise Measurements

TL;DR

This paper introduces a novel power recycling technique for co-axial Mach-Zehnder interferometers that significantly reduces phase noise, enhancing measurement sensitivity for low noise microwave applications.

Contribution

It presents the first experimental implementation of power recycling in microwave interferometers, achieving lower phase noise floors independent of input power levels.

Findings

8 dB reduction in phase noise floor at 1 kHz offset

Achieved -185 dBc/Hz phase noise at 13 dBm input power

Demonstrated improved sensitivity in low noise microwave measurements

Abstract

We present the first experimental study of a new type of power recycling microwave interferometer designed for low noise measurements. This system enhances sensitivity to phase fluctuations in a Device Under Test, independent of input power levels. The single sideband thermal white phase noise floor of the system has been lowered by 8 dB (reaching -185 dBc/Hz at 1 kHz offset frequency) at relatively low power levels (13 dBm).