阅读说明：本技术 一种近场磁场探测的探针 (Probe for near-field magnetic field detection ) 是由 不公告发明人 于 2020-04-20 设计创作，主要内容包括：本发明提供了一种近场磁场探测的探针,该探针包括光纤、光纤头、贵金属包覆层、金刚石颗粒,金刚石颗粒中含有氮-空位色心。通过光纤输入预定波长的激发光,激发光照射金刚石颗粒中的氮-空位色心,发射荧光,通过光纤接收荧光；同时,给金刚石颗粒施加预设频率范围的微波扫描信号。在微波和样品表面的磁场共同作用下,氮-空位色心能级分裂,通过测量荧光强度与微波频率之间的关系,确定样品表面的磁场。因为本发明将难以操控的光路部分设置于光纤内,使得整个探测系统结构紧凑,更方便应用。此外,该探针还可以用以近场光场、样品形貌的原位测量,所以,该探针可以实现原位的磁场、光场、形貌探测,满足更广泛科学研究的需要。(The invention provides a probe for near-field magnetic field detection, which comprises an optical fiber, an optical fiber head, a noble metal coating layer and diamond particles, wherein the diamond particles contain nitrogen-vacancy color centers. Inputting exciting light with a preset wavelength through an optical fiber, wherein the exciting light irradiates nitrogen-vacancy color centers in the diamond particles, emits fluorescence, and receives the fluorescence through the optical fiber; meanwhile, a microwave scanning signal of a predetermined frequency range is applied to the diamond particles. Under the combined action of the microwave and the magnetic field on the surface of the sample, the nitrogen-vacancy color center level is split, and the magnetic field on the surface of the sample is determined by measuring the relation between the fluorescence intensity and the microwave frequency. Because the invention arranges the light path part which is difficult to control in the optical fiber, the whole detection system has compact structure and is more convenient to use. In addition, the probe can be used for in-situ measurement of a near-field light field and the appearance of a sample, so that the probe can realize in-situ detection of the magnetic field, the light field and the appearance, and meet the requirements of more extensive scientific research.)

1. A probe for near field magnetic field detection, comprising: the optical fiber comprises an optical fiber, an optical fiber head, a noble metal coating layer and diamond particles;

one end of the optical fiber is connected with a light source, and the other end of the optical fiber is connected with the optical fiber head;

the optical fiber head is bent, and the cross-sectional size of the optical fiber head is gradually reduced;

the side surface of the tail end of the optical fiber head is provided with the noble metal coating layer;

the end face of the tail end of the optical fiber head is provided with the diamond particles, and nitrogen-vacancy color centers are arranged in the diamond particles.

2. The probe for near field magnetic field detection of claim 1, wherein: the end face of the tail end of the optical fiber head is circular, and the diameter of the circle is larger than 100 nanometers and smaller than 1 micrometer.

3. The probe for near field magnetic field detection of claim 2, wherein: the bottom surface size of the diamond particles is smaller than the size of the end face of the optical fiber head.

4. A probe for near field magnetic field detection as claimed in claim 3 wherein: the noble metal coating layer is made of gold material.

5. The probe for near field magnetic field detection of claim 4, wherein: the number of the diamond particles is 1.

6. The probe for near field magnetic field detection of claim 5, wherein: the diamond particles are in a pointed cone shape, and the top of the pointed cone is provided with a nitrogen-vacancy color center.

7. The probe for near field magnetic field detection according to any of claims 2 to 6, wherein: the noble metal coating also coats the bottom of the diamond particles.

Technical Field

The invention relates to the field of magnetic field detection, in particular to detection of near-field magnetic field detection.

Background

The near-field magnetic field detection has important significance for magnetic storage and research on the magnetic characteristics of materials.

In contrast to conventional magnetic resonance force microscopes, the inventive patent application CN109765508A proposes an apparatus for measuring magnetic field strength, the probe portion comprising a cantilever having a tip which is a diamond tip having nitrogen vacancy defects, the cantilever being a coaxial microwave antenna via which microwaves from a microwave power source are supplied to the diamond tip. In the detection, exciting light is applied to the tip, fluorescence emitted from the tip is detected, and the magnetic field intensity of the surface of the substance is obtained based on the detected fluorescence and the frequency of the microwaves. The invention transmits the microwave which is easy to be controlled to the diamond tip through the coaxial microwave antenna; excitation light and fluorescence which are difficult to control are arranged on an external light path, so that the operation is inconvenient. In addition, although the invention can measure the topography of the sample and the magnetic field at the surface of the sample simultaneously, it cannot measure the optical field at the sample in situ. This invention is inconvenient because many magnetic effects and light are inseparable, such as photomagnetic effects.

Disclosure of Invention

In order to solve the problems, the invention provides a probe for near-field magnetic field detection, which comprises an optical fiber, an optical fiber head, a noble metal coating layer and diamond particles; one end of the optical fiber is connected with the light source, and the other end of the optical fiber is connected with the optical fiber head; the optical fiber head is bent, and the sectional size of the optical fiber head is gradually reduced; a precious metal coating layer is arranged on the side surface of the tail end of the optical fiber head; the end face of the tail end of the optical fiber head is provided with diamond particles, and nitrogen-vacancy color centers are arranged in the diamond particles.

Furthermore, the end face of the optical fiber head is circular, and the diameter of the circle is more than 100 nanometers and less than 1 micrometer.

Further, the diamond particles have a bottom surface size smaller than the size of the end surface of the optical fiber tip.

Furthermore, the noble metal coating layer is a gold material.

Further, the number of diamond particles is 1.

Furthermore, the diamond particles are in a pointed cone shape, and a nitrogen-vacancy color center is arranged at the top of the pointed cone.

Further, the noble metal coating also coats the bottom of the diamond particles.

The invention has the beneficial effects that: the invention provides a probe for detecting a near-field magnetic field, which is characterized in that when the probe is applied to measure the magnetic field on the surface of a sample, exciting light with a preset wavelength is input through an optical fiber, the exciting light irradiates diamond particles, nitrogen-vacancy color centers in the diamond particles are stimulated to emit fluorescence, and the fluorescence is received through the optical fiber or an external light path; meanwhile, a microwave scanning signal of a predetermined frequency range is applied to the diamond particles. Under the combined action of the microwave and the magnetic field on the surface of the sample, the nitrogen-vacancy color center level is split, and the magnetic field on the surface of the sample is determined by measuring the relation between the fluorescence intensity and the microwave frequency. Because the invention arranges the light path part which is difficult to control in the optical fiber, the whole detection system has compact structure and is more convenient to use. Because of the light transmission of the diamond particles, the probe can also be used as a near-field optical probe for detecting the light field on the surface of the sample. The diamond particles can also be used as an atomic force probe to detect the surface topography of a sample. Therefore, the probe can realize in-situ detection of a magnetic field, an optical field and the shape, and meet the requirement of more extensive scientific research.

The present invention will be described in further detail below with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic diagram of a probe for near field magnetic field detection.

FIG. 2 is a schematic diagram of yet another near-field magnetic field detection probe.

In the figure: 1. an optical fiber; 2. an optical fiber head; 3. a noble metal coating layer; 4. diamond particles.

Detailed Description

To further explain the technical means and effects of the present invention adopted to achieve the intended purpose, the following detailed description of the embodiments, structural features and effects of the present invention will be made with reference to the accompanying drawings and examples.