Experimental diamond photonics: Current state and prospects. Part II

The technique for fabricating microcavities from diamond and other materials is described and their main parameters are reported. The possibilities of using color centers in diamond which interact with optical cavities as single-phonon sources and in quantum information processing are discussed. Several variants of integration of the color centers with high-Q cavities are considered.     

Experimental diamond photonics: Current state and prospects. Part I

In this review, we generalize and systematize the experimental data of the past few years concerning the implementation of solid-state photonic structures based on synthetic diamond materials. We list the physical properties and performances of the available devices and describe the technologies for their fabrication. The aim of the review is to establish whether the quality of the available quantum network elements, including various waveguide structures and microcavities interacting with the color centers, meets the concept of a solid-state photonic chip.     

Whispering gallery modes in a spherical microcavity with a photoluminescent shell

Whispering-gallery mode spectra in optical microcavities based on spherical silica particles coated with a thin photoluminescent shell of hydrogenated amorphous silicon carbide are studied. The spectral positions of the whispering-gallery modes for spherical microcavities with a shell are calculated. The dependence of the spectral distance between the TE and TM modes on the shell thickness is examined.     

Luminescence of Nanodiamond Driven by Atomic Functionalization: Towards Novel Detection Principles

High biocompatibility, variable size ranging from ≈5 nm, stable luminescence from its color centers, and simple carbon chemistry for biomolecule grafting make nanodiamond (ND) particles an attractive alternative to molecular dyes for drug‐delivery. A novel method is presented that can be used for remote monitoring of chemical processes in biological environments based on color changes from photoluminescent (PL) nitrogen‐vacancy (NV) centers in ND. The NV luminescence is driven chemically by alternating the surface chemical potential by interacting atoms and molecules with the diamond surface. Due to the small ND size, the changes of the surface chemical potential modify the electric field profile at the diamond surfaces (i.e., band bending) and intermingle with the electronic NV states. This leads to changes in NV^?/NV° PL ratio and allows construction of optical chemo‐biosensors operating in cells, with PL visible in classical confocal microscopes. This phenomenon is demonstrated on single crystal diamond containing engineered NV centers and on oxidized and hydrogenated ND in liquid physiological buffers for variously sized ND particles. Hydrogenation of NDs leads to quenching of luminescence related to negatively charged (NV^?) centers and as a result produces color shifts from NV^? (638 nm) to neutral NV° (575 nm) luminescence. How the reduction of diamond size increases the magnitude of the NV color shift phenomena is modeled.     

Planar microcavity containing luminescent diamond particles with embedded silicon-vacancy color centers in its active layer

A planar hybrid microcavity containing isolated diamond particles with embedded silicon-vacancy (Si-V) color centers in its active layer is fabricated by plasma-enhanced chemical vapor deposition. Distributed Bragg reflectors are produced on the basis of alternating quarter-wave a-Si_{1 ? x} C _x :H and a-SiO₂ layers. The color centers are controllably introduced from the gas phase during the course of growth of the diamond particles. A narrowing to 5 nm of the zero-phonon line at a wavelength of 738 nm and suppression of the phonon wing in the photoluminescence spectrum of the Si-V color centers are achieved.     

From Fancy Blue to Red: Controlled Production of a Vibrant Color Spectrum of Fluorescent Diamond Particles

The current study reports a breakthrough method for production of multicolor diamond particulates using a rapid thermal annealing (RTA) approach with precise temperature and time control, enabling annealing of diamond particulates up to 2100 °C without extensive graphitization. The RTA method generates conditions which allow formation of one‐, two‐, and three‐atom nitrogen complexes with vacancies in electron irradiated type Ib synthetic diamond, providing vibrant luminescence in the red, green, and blue spectral ranges, correspondingly. Controlled and highly reproducible formation of specific color centers previously not possible in type Ib synthetic diamond particles opens new opportunities for particulate diamond in a plethora of fluorescence imaging applications in biological and industrial fields.     

金刚石氮-空位色心零声子线的受激辐射放大

为了解决在基于金刚石氮-空位(NV)色心的磁场高灵敏度测量中,高速获取磁场信号引起的NV色心发光强度的微小变化的技术瓶颈问题,自行设计出一套能够实现金刚石NV色心自发辐射和受激辐射信号同步测量的光学系统,并利用一个长焦距透镜收集金刚石NV色心受激辐射信号,从而尽最大可能地滤除金刚石NV色心的自发辐射信号,提高测量受激放大增益的信噪比。实验中成功观察到NV色心零声子线的受激辐射放大,分析了抽运光功率、信号光功率、抽运光偏振方向和信号光偏振方向对放大特性的影响。结果表明,通过对抽运光和信号光相关参量的优化调整,最终获得了10.5%的受激辐射增益。该研究为实现NV光放大远程磁场监测奠定了研究基础。     

玻璃球形微腔中量子点发光行为研究

制备出了尺寸在μm量级的球形玻璃微腔,在球形微腔中嵌入了CdSeS半导体纳米团簇结构,用一束激光激发单个微球时,球形微腔中CdSeS量子点的发光通过全内反射实现了球形回音壁模式的腔模共振,实现了受限电子态和光子态的耦合。     

Spatial and Hyperfine Characteristics of SiV– and SiV0 Color Centers in Diamond: DFT Simulation

Semiconductors - One of the most promising platforms to implement quantum technologies are coupled electron-nuclear spins in diamond in which the electrons of paramagnetic color centers play a role...     

基于回音壁模式的球形光学微腔实验研究

采用聚苯乙烯材料制作出不同直径(50～250μm)的球形光学微腔并实现了微腔与锥形光纤的耦合,测量了球形光学微腔在1570～1576nm波长范围内的吸收光谱,实验结果表明球形光学微腔在这一波长范围内可发生基于回音壁模式(WGM)的光学谐振,且WGM吸收峰的相邻波长间隔随着聚苯乙烯微球直径的增大而减小。通过吸收光谱计算了聚苯乙烯微球在其本征频率下的品质因子,结果表明微球品质因子数量级均在104以上。     

Increase of the Zero-Phonon-Line Emission from Color Centers in Nanodiamonds by Coupling with Dielectric Nanocavity

Semiconductors - Development of single photon sources based on color centers in diamond nanoparticles requires a sufficient increase in their brightness. Conventionally, this may be accomplished by...     

基于金刚石NV色心的带状线芯片微波场成像

为了满足集成微波器件进行高分辨率微波近场测量的需求,本论文提出了一种基于金刚石氮空位（Nitrogen-Vacancy,NV）色心的微波近场成像技术.该技术可用于查找芯片等集成微波器件的干扰源和信号串扰.此微波近场成像方法采用金刚石NV色心颗粒作为场传感器,其中金刚石颗粒固定在锥形光纤的末端.由于塞曼效应,NV色心的光探测磁共振（Optical Detection Magnetic Resonance,ODMR）谱在外部静磁场环境中会分裂成为8个峰,通过测量共振峰频点的Rabi振荡谱,能够得到Rabi频率,接着通过2.8MHz/Gauss换算得出该处的微波场强度,最后通过将所测得所有数据点进行二维图像处理即可得到所测芯片和集成微波器件的表面微波场近场图像.     

线性偏振光被微粒子场散射的特性研究

本文提供了线偏振光通过复合微粒子场后的侧向散射效应，并进行了探讨分析，实验采用了４种粒子场浓度，２种直径的圆形粒子，从粒子空间尺寸，粒子浓度，粒子直径大小，探测角度和深度位置等多个方面考察实验数据与粒子场特性的联系，发现在一定条件下引起入射光退偏振的主要因素是粒子尺寸和场内粒子的浓度。     

多晶金刚石固结磨料研磨垫精研石英玻璃的性能探索

通过粘结剂将单晶金刚石制成粒径更大的多晶金刚石。采用SEM观察了多晶金刚石的微观形貌,分别制备了单晶和多晶金刚石固结磨料研磨垫,比较了单晶与多晶金刚石固结磨料研磨垫的研磨性能。结果表明:单晶金刚石固结磨料垫与多晶金刚石固结磨料垫精研石英玻璃的表面粗糙度相似;但多晶金刚石固结磨料垫的材料去除率更高且稳定;多晶金刚石在研磨过程中的微破碎,确保了其自修整过程的实现。另外,多晶金刚石研结磨料垫研磨的石英玻璃亚表面损伤层深度小,约为原始单晶金刚石粒径的1/2。     

激光诱导等离子体在金刚石表面沉积金属薄膜

介绍了一种利用脉冲准分子激光轰击钛(或镍)靶诱导出等离子体从而在金刚石颗粒表面沉积Ti，Ni等金属保护层的新方法。使用抗压强度测定仪测定并比较了金刚石颗粒表面镀敷金属层前后的抗压强度值，使用金相显微镜观察了金刚石镀膜前后的表面微观状态，并利用x射线衍射仪(XRD)测定了沉积在金刚石颗粒表面金属层的组份。结果表明，利用脉冲准分子激光在金刚石颗粒表面镀Ti后其抗压强度显著增加，而且由于脉冲准分子激光轰击金属靶材后诱导的等离子体能量较高，即使在非高温工作情况下也可在金刚石表面生成TiC膜，这大大提高了金属膜层与金刚石颗粒之间的结合紧密度，这种TiC膜层的形成对于延长金刚石锯片的使用寿命具有重大意义。     

面向微集成的金刚石NV色心与微波天线的一体化

针对金刚石氮空位(NV)色心量子传感器中微波天线体积大、无法与金刚石紧密接触造成天线与金刚石位置不固定、引起传感器灵敏度低的问题,设计了一种将微波天线集成到金刚石NV色心的一体化方法.采用导电性更强的金薄膜作为天线材料,通过高频结构模拟器(HFSS)仿真软件确定天线尺寸.利用微纳加工工艺和磁控溅射技术在金刚石NV色心表...     

Nanoelectromechanical diamond structures in quantum informatics. Part I

Techniques for fabricating nanomechanical diamond systems and their use in modern micro- and nanoelectronics are reviewed. The primary focus is the experimental techniques for controlling the quantum state of nitrogen-vacancy centers in diamond by mechanical actions. Optimization of the working characteristics of diamond resonators is discussed.     

Bimodal and monomodal diamond particle effect on the thermal properties of diamond-particle-dispersed Al–matrix composite fabricated by SPS

Diamond-particle-dispersed aluminum (Al) matrix composites consisting of monomodal and bimodal diamond particles were fabricated in spark plasma sintering process, where the mixture of diamond, pure Al and Al–5 mass% Si alloy powders were consolidated in liquid and solid co-existent state. Microstructures and thermal properties of the composites fabricated in such a way were investigated and the monomodal and bimodal diamond particle effect was evaluated on the thermal properties of the composites. The composites can be well consolidated in a temperature range between 773 K and 878 K and scanning electron microscopy detects no reaction product at the interface between the diamond particle and the Al matrix. Relative packing density of the composite containing monomodal diamond particles decreased from 99.1% to 87.4% with increasing volume fraction of diamond between 50% and 60%, whereas that of the composite containing bimodal diamond particles was higher than 99% in a volume fraction of diamond up to 65%. The thermal conductivity of the composite containing bimodal diamond particles was higher than that of the composite containing monomodal diamond particles in a volume fraction of diamond higher than 60%. The coefficients of thermal expansion (CTEs) of the diamond-particle-dispersed Al–matrix composites fall in the upper line of Kerner model, indicating good bonding between the diamond particle and the Al matrix in the composite. The thermal conductivity of the composite containing 70 vol.% bimodal diamond particles was 578 W/m K and its CTE was 6.72 × 10⁻⁶ at R.T.     

高导热金刚石/玻璃复合材料的制备和性能研究

首先对金刚石颗粒进行化学镀Cu,并控制氧化,从而在金刚石颗粒表面获得Cu-Cu2O复合结构。然后,在800℃无压烧结制备了金刚石/玻璃复合材料,观察了其表面和界面形貌,并测定了其相对密度和热导率。结果表明,通过对镀Cu金刚石的控制氧化,明显改善了玻璃对金刚石颗粒表面的润湿性,避免了玻璃对金刚石颗粒表面的侵蚀,提高了复合材料的热导率;复合材料的热导率随金刚石含量的增加而增加,当金刚石质量分数为70%时,热导率最高达到了14.420W/(m·K)。     

Dislocation electrical conductivity of synthetic diamond films

A relationship between the electric resistance of single-crystal homoepitaxial and polycrystalline diamond films and their internal structure has been investigated. It is established that the electrical conductivity of undoped homoepitaxial and polycrystalline diamond films is directly related to the dislocation density in them. A relation linking the resistivity ρ (～10¹³–10¹⁵ Ω cm) with the dislocation density Γ (～10¹⁴?4 × 10¹⁶ m^?2) is obtained. The character of this correlation is similar for both groups of homoepitaxial and polycrystalline diamond films. Thin (～1–8 μm) homoepitaxial and polycrystalline diamond films with small-angle dislocation boundaries between mosaic blocks exhibit dislocation conductivity. The activation energy of dislocation acceptor centers was calculated from the temperature dependence of the conductivity and was found to be ～0.3 eV. The conduction of thick diamond films (h > 10 μm) with the resistivity ρ ≈ 10⁸ Ω cm is determined by the conduction of intercrystallite boundaries, which have a nondiamond hydrogenated structure. The electronic properties of the diamond films are compared with those of natural semiconductor diamonds of types IIb and Ic, in which dislocation acceptor centers have activation energies in the range 0.2–0.35 eV and are responsible for hole conduction.