Fabrication of oriented NV center arrays in diamond via femtosecond laser writing and reorientation

TL;DR

This paper introduces a femtosecond laser annealing method to reorient laser-written NV centers in diamond, creating ordered arrays with uniform orientation to improve quantum sensing performance.

Contribution

It presents a novel all-optical technique for reorienting NV centers in diamond, enabling scalable fabrication of oriented NV arrays for enhanced quantum magnetometry.

Findings

Achieved deterministic alignment of NV centers along the optical axis.

Demonstrated reorientation in both (100) and (111) diamond substrates.

Enabled creation of spatially ordered NV arrays with uniform orientation.

Abstract

Nitrogen-vacancy (NV) centers in diamond are widely recognized as highly promising solid-state quantum sensors due to their long room temperature coherence times and atomic-scale size, which enable exceptional sensitivity and nanoscale spatial resolution under ambient conditions. Ultrafast laser writing has demonstrated the deterministic spatial control of individual NV$^-$ centers, however, the resulting random orientation of the defect axis limits the magnetic field sensitivity and signal contrast. Here, we present an all-optical approach for reorienting laser-written NV$^-$ centers to lie along a specific crystallographic axis using femtosecond laser annealing. This technique enables the creation of spatially ordered NV$^-$ arrays with uniform orientation, for enhancing performance for quantum magnetometry. We achieve deterministic alignment along the optical axis in both (100)- and (111)-oriented diamond substrates, paving the way for scalable, high-performance quantum devices based on orientation-controlled NV$^-$ centers.