# Electro-mechano-optical detection of nuclear magnetic resonance

## TL;DR

This paper introduces a novel method for nuclear magnetic resonance detection that converts RF signals into optical signals using a silicon nitride membrane, potentially enhancing sensitivity and enabling new amplification techniques.

## Contribution

It demonstrates the first electro-mechano-optical NMR detection system that up-converts RF signals to optical signals via a high-stress silicon nitride membrane.

## Key findings

- Optical NMR detection achieved without sacrificing traditional versatility.
- Signal-to-noise ratio can surpass conventional electrical methods with increased coupling.
- Potential for mechanical amplification and laser cooling of nuclear spins.

## Abstract

Signal reception of nuclear magnetic resonance (NMR) usually relies on electrical amplification of the electromotive force caused by nuclear induction. Here, we report up-conversion of a radio-frequency NMR signal to an optical regime using a high-stress silicon nitride membrane that interfaces the electrical detection circuit and an optical cavity through the electro-mechanical and the opto-mechanical couplings. This enables optical NMR detection without sacrificing the versatility of the traditional nuclear induction approach. While the signal-to-noise ratio is currently limited by the Brownian motion of the membrane as well as additional technical noise, we find it can exceed that of the conventional electrical schemes by increasing the electro-mechanical coupling strength. The electro-mechano-optical NMR detection presented here opens the possibility of mechanical parametric amplification of NMR signals. Moreover, it can potentially be combined with the laser cooling technique applied to nuclear spins.