Speaker
Description
Non-invasive, high-resolution detection of neuronal activity remains a key challenge in neuroscience and bioimaging. Nitrogen-vacancy (NV) center magnetometry is a promising quantum sensing technology capable of detecting the weak magnetic fields generated by neuronal currents.A key requirements to obtain good quantum sensors with optimal properties is the fabrication. While ion implantation is the dominant method, laser irradiation has shown promising but is still comparatively less explored.~
In the first part of this talk, I present the creation of NV centers using a 500 kHz, 515 nm laser in a single step process with no separate seed/vacancy diffusion pulses and no annealing step. By varying energy per pulse, laser exposure time and depth, we identify how this parameters affect the writing process and the impact of other laser writing processes such as graphitization, ablation and self-focusing.
In the second part, we present a novel approach using bias-free, single-frequency continuous-wave optically detected magnetic resonance (CW-ODMR) to enable sensitive, non-invasive neuronal signal detection with single-cell resolution using a commercial diamond. By removing the bias magnetic field, we avoid perturbing natural neuronal behavior, enhancing biocompatibility. Restricting detection to a single frequency further reduces acquisition time, enabling fast imaging. Our method achieves a temporal resolution of 0.2 ms. We validated our system using a biomimetic gold wire model, applying a 5 V, 2 ms stimulus. A reproducible 1% contrast was observed in single-shot measurements, clearly correlating with the input signal. We also present analysis of signal origin, contrast sensitivity, and system limitations.
Together, these studies advance both the fabrication and application of NV centers paving the way toward real-time quantum bioimaging tools with high sensitivity and resolution.
| Which topic best fits your talk? | Optics and Photonics |
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