Method for improving collection efficiency of diamond NV color center fluorescence

Abstract

The invention discloses a method for improving collection efficiency of diamond NV color center fluorescence. The method comprises the following steps of forming an optical resonator by coupling a nano-diamond and a microsphere cavity based on the Purcell effect, integrating a microwave antenna thereon to prepare a microsphere cavity (200-500 microns) containing the nano-diamond, exciting the diamond NV color center to generate fluorescence by 532nm laser, and enhancing and collecting the fluorescence using a whispering wall mode such that the fluorescence generated by the diamond NV color center can be continuously circulated in the microsphere cavity, thereby establishing a strong light field and directly achieving the collection of fluorescence using the fiber connected to the sphere cavity. The method combines nano-diamond with optical microcavity with low requirements on preparation process, has the characteristics such as low cost, small mode volume and high energy density, realizes excitation and efficient collection of diamond NV color center fluorescence, and is expected to realize integrated application of NV color center based high sensitivity quantum sensors.

Description

technical field [0001] The invention relates to the field of fluorescence detection of diamond NV color centers, specifically a method for improving the fluorescence collection efficiency of diamond NV color centers, which is expected to be applied to high-sensitivity quantum sensors based on NV color centers. Background technique [0002] Various lattice defects are ubiquitous in diamond crystals, among which the nitrogen vacancy (NV) color center defect caused by impurity nitrogen has stable optical properties, electron spin properties and ideal solid-state qubit properties at room temperature. It is widely used in quantum storage, quantum information processing, bioluminescent labeling, and super-resolution imaging. Diamond NV color centers have a stable energy level structure and superior luminescence characteristics, can be manipulated by laser and microwave, and can realize high-sensitivity physical quantity detection. Most of the research and application of diamond N...

AI Technical Summary

Problems solved by technology

[0003] Due to the small coupling strength between the NV color center and the electromagnetic field, the fluorescence collection efficiency of the NV color center has always been low. Strengthening or processing diamonds to produce some special structures and other methods, the experimental operations required for the realization of these methods are very complicated, the experimental requirements are very high and the processing quality is not easy to guarantee, which is not conducive to popularization

There are also some studies that use multiple photodetectors to collect the fluorescence of NV color centers from multiple directions, but this makes the entire diamond NV color center fluorescence excitation collection system too large, which limits its application in small sensitive sensors.

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