Diamond laser system achieves 100% optical contrast in magnetic-field readout

Researchers at Fraunhofer IAF have developed a laser-enhanced quantum sensor that combines high magnetic-field sensitivity with a large dynamic range. Using laser threshold magnetometry, they improved the ratio of sensitivity and dynamic range by a factor of up to 590 compared with state-of-the-art approaches. The breakthrough is enabled by the first demonstration of 100% optical contrast, combined with strong laser readout signals. The results, published in Nature Communications, open up new prospects for medical diagnostics, navigation, and resource exploration.