Single quantum dot scanning near-field optical microprobe and system, detection device and method

Abstract

The invention relates to the technical field of scanning probe imaging, and discloses a near-field probe and a probe system based on a single quantum dot as well as a detection device and a method based on the probe system. In a single quantum dot scanning near-field optical microprobe, the single quantum dot is loaded to the point of a dielectric needle through electrostatic force or a chemical adhesive as a probe, and the point of the dielectric needle is a conical fiber or an atomic force microscope probe. The near-field probe system can effectively overcome the defect that a traditional scanning near-field optical probe distorts optical properties of samples and is low in signal-to-noise ratio and low in repeatability; the imaging resolution of the single quantum dot near-field probe can reach the same magnitude of single quantum dot dimension, and is generally superior to 10 nanometer space resolution. The detection method is based on fluorescence intensity imaging and fluorescence lifetime imaging, and can sense the physical quantity information of multiple dimensions such as sample shape, material composition and optical near-field distribution.

Description

technical field [0001] The invention relates to the technical field of scanning probe imaging, in particular to a preparation technology of a near-field probe based on a single quantum dot. The near-field imaging of the probe is based on the change of local density of states. Background technique [0002] The development of nanotechnology drives people to continue to advance research to smaller and smaller scales. The existence of the optical diffraction limit makes it impossible for people to optically characterize nanoscale objects using conventional methods, and break the optical diffraction limit to optically characterize nanoscale objects. The near-field scanning optical microscope (SNOM) came into being. As the core probe of SNOM, it can be divided into two types: scattering type and transmission type according to the imaging principle. The transmission-type probe is prepared by designing a nanoscale light-through hole on the scanning probe. The common preparation met...

AI Technical Summary

Problems solved by technology

Among them, the single molecule needs to be embedded in the film to stabilize the light emission, and the size of the film cannot be too small, resulting in insignificant effect, which leads to poor signal-to-noise ratio and resolution

The diamond NV color center has a small absorption cross-section and a wide spectrum, resulting in no obvious enhancement based on fluorescence enhancement or local density of states

The imaging basis of the previously reported single quantum dot near-field probe is fluorescence enhancement. This method needs to match the excitation wavelength and the scattering peak of the object to be imaged, and needs to select a suitable polarization direction. The imaging conditions are relatively complex and the signal-to-noise ratio is high. It means that the excitation power of the single quantum dot is very large, which may cause the fluorescence quenching of the single quantum dot

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