Optical Simulation And Experimental Preparation Of Diamond Nanocolumns

There are a large number of vacant color centers in diamond,but the number of photons emitted from the color centers in bulk diamond is relatively low.Therefore,in order to increase the number of photons,a variety of structures have been proposed,among which the nanocolumn structure has attracted much attention.It has been shown that the number of photons emitted by the nanocolumn structure is an order of magnitude higher than that emitted by the bulk structure.Since diamond nanocolumn is an effective structure to enhance the color center single photon source,and increasing the electric field intensity inside the nanocolumn can effectively increase the number of emitted photons,the internal field intensity distribution and the maximum value of the field intensity inside the nanocolumn will provide an effective reference for the placement of the diamond color center.In this paper,the finite difference time domain(FDTD)method was used to simulate the structural size(diameter and height),pump wavelength and array spacing of diamond nanocolumns,and the variation law of electric field intensity inside diamond nanocolumns was studied,and the maximum electric field intensity in the nanocolumns under the optimal parameters was found.At the same time,the experimental preparation method of diamond nanocolumn array was explored.The main contents of the study and the main results are as follows:Firstly,the influence factors of light field distribution and electric field intensity in a single diamond nanocolumn were studied.Through investigation,it is found that the light field distribution inside the diamond nano-column is greatly affected by the size of the nano-column and the wavelength of the pump light.By changing the diameter,height and pumping wavelength of the nanoruds,the relationship between the parts of the internal field intensity and the size of the nanoruds,and the relationship between the maximum of the internal field intensity and the size and wavelength of the nanoruds were obtained,and the optimal structure size with the maximum of the internal field intensity was found.The results show that when the pump wavelength is constant,the maximum value of the internal field intensity varies periodically with the size of the nanometer column,and there are maximum values and maximum values in a certain range.When the size range of nanocolumn is fixed,the maximum point of the field intensity inside the nanocolumn moves with the maximum of the pump wavelength,but the overall trend is almost constant.Then,when the pump wavelength is 532 nm,the maximum field intensity inside the diamond nanometer column is 16.673V/m,and the corresponding diameter and height of the nanometer column are 825 nm and 631 nm.The maximum point is located on the central axis 599 nm away from the lower surface of the nanometer column.Secondly,the light field distribution and electric field intensity of two nanorods and3×3 nanorods array are simulated.The influence of the distance between diamond nanoruds on the light field inside the nanoruds was studied,and the optimal distance between the maximum field intensity and the bottom of the nanoruds was found.The results show that,with the increase of column spacing,when the pump wavelength and the size of the nanocolumn remain unchanged,the maximum value of the internal field intensity generally increases first,then decreases and finally becomes stable,while the maximum value of the field intensity generally decreases first and finally becomes stable for the two nanocolumns.For the 3×3 nanometer column array,the maximum value of the internal field intensity on the whole also showed a trend of first increasing,then decreasing and finally stabilizing,while the maximum value of the field intensity showed a trend of first decreasing,then increasing and finally stabilizing.Thirdly,the experimental method of preparing diamond nanocolumn array was studied.Diamond nanocolumn arrays were prepared by using two different experimental methods.One is to grow diamond from bottom to top by using AAO template,and then prepare diamond nanocolumn array.One is to use metal particles as masks to etch diamond from top to bottom,and then prepare diamond nanocolumn arrays.