Related Experiment Video
Updated: Jul 4, 2025

Frequency Mixing Magnetic Detection Scanner for Imaging Magnetic Particles in Planar Samples
Published on: June 9, 2016
Multipoint Lock-in Detection for Diamond Nitrogen-Vacancy Magnetometry Using DDS-Based Frequency-Shift Keying
Qidi Hu1,2, Luheng Cheng1,2, Yushan Liu1
1Research Center for Quantum Sensing, Zhejiang Lab, Hangzhou 311000, China.
Abstract:
In recent years, the nitrogen-vacancy (NV) center in diamonds has been demonstrated to be a high-performance multiphysics sensor, where a lock-in amplifier (LIA) is often adopted to monitor photoluminescence changes around the resonance. It is rather complex when multiple resonant points are utilized to realize a vector or temperature-magnetic joint sensing. In this article, we present a novel scheme to realize multipoint lock-in detection with only a single-channel device. This method is based on a direct digital synthesizer (DDS) and frequency-shift keying (FSK) technique, which is capable of freely hopping frequencies with a maximum of 1.4 GHz bandwidth and encoding an unlimited number of resonant points during the sensing process. We demonstrate this method in experiments and show it would be generally useful in quantum multi-frequency excitation applications, especially in the portable and highly mobile cases.
Related Concept Videos
Double Resonance Techniques: Overview
Spin decoupling is usually achieved by...
¹³C NMR: ¹H–¹³C Decoupling
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
Two-Dimensional (2D) NMR: Overview
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse....
NMR Spectrometers: Resolution and Error Correction
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
Atomic Nuclei: Magnetic Resonance

