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We present a phenomenological model and Finite Element simulations to describe the depth variation of mass density and strain of ion-implanted single-crystal diamond. Several experiments are employed to validate the approach: firstly, samples implanted with 180 keV B ions at relatively low fluences are characterized using high-resolution X-ray diffraction (HR-XRD); secondly, the mass density variation of a sample implanted with 500 keV He ions well above its amorphization threshold is characterized with Electron Energy Loss Spectroscopy (EELS). At high damage densities, the experimental depth profiles of strain and density display a saturation effect with increasing damage and a shift of the damage density peak towards greater depth values with respect to those predicted by TRIM simulations, which are well accounted for in the model presented here. The model is then further validated by comparing TEM-measured and simulated thickness values of a buried amorphous carbon layer formed at different depths by implantation of 500 keV He ions through a variable-thickness mask to simulate the simultaneous implantation of ions at different energies., Comment: 40 pages, 9 figures, submitted to Physical Review B

We report on the systematic characterization of conductive micro-channels fabricated in single-crystal diamond with direct ion microbeam writing. Focused high-energy (~MeV) helium ions are employed to selectively convert diamond with micrometric spatial accuracy to a stable graphitic phase upon thermal annealing, due to the induced structural damage occurring at the end-of-range. A variable-thickness mask allows the accurate modulation of the depth at which the microchannels are formed, from several {\mu}m deep up to the very surface of the sample. By means of cross-sectional transmission electron microscopy (TEM) we demonstrate that the technique allows the direct writing of amorphous (and graphitic, upon suitable thermal annealing) microstructures extending within the insulating diamond matrix in the three spatial directions, and in particular that buried channels embedded in a highly insulating matrix emerge and electrically connect to the sample surface at specific locations. Moreover, by means of electrical characterization both at room temperature and variable temperature, we investigate the conductivity and the charge-transport mechanisms of microchannels obtained by implantation at different ion fluences and after subsequent thermal processes, demonstrating that upon high-temperature annealing, the channels implanted above a critical damage density convert to a stable graphitic phase. These structures have significant impact for different applications, such as compact ionizing radiation detectors, dosimeters, bio-sensors and more generally diamond-based devices with buried three-dimensional all-carbon electrodes.

Ion implantation is widely used to modify the structural, electrical and optical properties of materials. By appropriate masking, this technique can be used to define nano- and micro-structures. However, depending on the type of mask used, experiments have shown that vacancy-related substrate modification can be inferred tens of microns away from the edge of the mask used to define the implanted region. This could be due to fast diffusion of vacancies from the implanted area during annealing or to a geometric effect related to ion scattering around the mask edges. For quantum and single-atom devices, stray ion damage can be deleterious and must be minimized. In order to profile the distribution of implantation-induced damage, we have used the nitrogen-vacancy colour centre as a sensitive marker for vacancy concentration and distribution following MeV He ion implantation into diamond and annealing. Results show that helium atoms implanted through a mask clamped to the diamond surface are scattered underneath the mask to distances in the range of tens of micrometers from the mask edge. Implantation through a lithographically defined and deposited mask, with no spacing between the mask and the substrate, significantly reduces the scattering to, 21 pages, 4 figures

In this proceedings we will present a research project financed by Piedmont regional government (Italy) and finalized to the realization and commercialization of functional devices for cellular bio-sensing based on diamond. Partners of the project are: Crisel Instruments, Torino University, Torino Polytechnic, INRIM, Politronica, Bionica Tech, Ulm University Here the main features of the final devices will be briefly summarized. We envisage an active diamond-based cellular substrate that can simultaneously stimulate and detect a variety of signals (chemical, optical, electrical) to and from neuroendocrine cells, in a fully biocompatible environment for the cellular system under test. Such a device can be realized by fully exploiting the peculiar properties of diamond: optical transparency, biocompatibility, chemical inertness, accessibility to a conductive graphite-like phase; properties that will be further explored and tested during the project.

Manufacturing of miniaturized photonic devices based on diamond technology is possible by implanting the pristine material with highly energetic particles. Here we report on the spectral characterization of the optical constants of proton-irradiated diamond. Absorption of the irradiated zones was estimated in the UV-vis-NIR from direct transmittance measurement using a dedicated setup with enhanced spatial resolution. The OPD data providing an estimation of the thickness of the damaged area and its depth profile, have allowed then evaluation of the extinction coefficient from the transmission measurements. Simultaneous variation of dispersive optical constants makes the modeling significantly more complicated compared to the above cited monochromatic study. Keywords: Optical constants; Diamond crystal; Ion implantation 1. INTRODUCTION Manufacturing of miniaturized photonic devices based on diamond technology is possible by implanting the pristine material with highly energetic particles. Theoretically the optical constants of irradiated material may vary from the values typical for pristine diamond to those of graphite, however only precise knowledge of the optical constants allows calculation of performance of the novel photonic micro- and nano-devices like e.g. diamond-based waveguiding structures

A method for obtaining a smooth, single crystal diamond surface is presented, whereby a sacrificial defective layer is created by implantation and graphitized by annealing before being selectively etched. We have used O+ at 240 keV, the main process variables being the ion fluence (ranging from 3x10^15 cm^-2 to 3x10^17 cm^-2) and the final etching process (wet etch, H2 plasma and annealing in air). The substrates were characterized by atomic force microscopy, optical profilometry and white beam X-ray topography. The influence of the various process parameters on the resulting lift-off efficiency and final surface roughness is discussed. An O+ fluence of 2x10^17 cm^-2 was found to result in sub-nanometre roughness over tens of um^2., Comment: 4 pages, 4 figures

This paper reports on the fabrication and characterization of a high purity monocrystalline diamond detector with buried electrodes realized by the selective damage induced by a focused 6 MeV carbon ion beam scanned over a pattern defined at the micrometric scale. A suitable variable-thickness mask was deposited on the diamond surface in order to modulate the penetration depth of the ions and to shallow the damage profile toward the surface. After the irradiation, the sample was annealed at high temperature in order to promote the conversion to the graphitic phase of the end-of-range regions which experienced an ion-induced damage exceeding the damage threshold, while recovering the sub-threshold damaged regions to the highly resistive diamond phase. This process provided conductive graphitic electrodes embedded in the insulating diamond matrix; the presence of the variable-thickness mask made the terminations of the channels emerging at the diamond surface and available to be connected to an external electronic circuit. In order to evaluate the quality of this novel microfabrication procedure based on direct ion writing, we performed frontal Ion Beam Induced Charge (IBIC) measurements by raster scanning focused MeV ion beams onto the diamond surface. Charge collection efficiency (CCE) maps were measured at different bias voltages. The interpretation of such maps was based on the Shockley-Ramo-Gunn formalism., 18 pages, 6 figures

Doxorubicin is one of the most employed anticancer drugs, but its efficacy is limited by the onset of adverse effects such as drug resistance, due to the drug efflux via P-glycoprotein (Pgp). Several factors are associated to a high Pgp activity, including the amount of cholesterol in plasma membrane, which is essential to maintain the pump function. In this work we started from the following observations: 1) the drug-resistant colon cancer HT29-dx cells had a higher content of cholesterol in plasma membrane than drug-sensitive HT29 cells and a higher activity of Pgp, which was decreased by the cholesterol-lowering agent β-methyl-cyclodextrin; 2) HT29-dx cells showed a higher synthesis of endogenous cholesterol and a higher expression of the low-density lipoprotein receptor (LDLR); 3) the anti-cholesterolemic drug simvastatin reduced the cholesterol synthesis, increased the synthesis of LDLR and lowered the Pgp activity in resistant cells. In order to circumvent drug resistance we designed a new liposomal doxorubicin, conjugated with a recombinant LDLR-binding peptide from human apoB100: this LDL-masked doxorubicin ("apo-Lipodox") was efficiently internalized by a LDLR-driven endocytosis and induced cytotoxic effects in HT29-dx cells, reversing their drug resistance. Its efficacy was further increased by simvastatin, which up-regulates the LDLR levels and contemporarily reduces the Pgp activity, thus increasing the liposomes uptake and limiting the drug efflux. We propose that the association of liposomal doxorubicin and statins may be a future promising strategy to reverse drug-resistance in human cancer cells.

We demonstrate the feasibility of fabricating light-waveguiding microstructures in bulk single-crystal diamond by means of direct ion implantation with a scanning microbeam, resulting in the modulation of the refractive index of the ion-beam damaged crystal. Direct evidence of waveguiding through such buried microchannels is obtained with a phase-shift micro-interferometric method allowing the study of the multi-modal structure of the propagating electromagnetic field. The possibility of defining optical and photonic structures by direct ion writing opens a range of new possibilities in the design of quantum-optical devices in bulk single crystal diamond., Comment: 10 pages, 4 figures

In this paper an overview is given on recent results obtained in the framework of an Italian/Croatian collaboration aimed to explore the potential of techniques based on focused MeV ion beams to locally modify the structural, electrical and optical features of diamond.Experiments were carried out using light (H, He, C) ion beams with energies of the order of MeV, focused to micrometer-size spot and raster scanned onto the surface of monocrystalline (IIa or Ib) diamond samples. Different energies, ion species and fluences were used, in conjunction with variable thickness masks and post annealing processes, to define three-dimensional structures in diamond, whose electrical/optical/structural properties have been suitably characterized. Finite element numerical methods have been employed in the modeling of the material modification and in device design.

A fine control of the variation of the refractive index as a function of structural damage is essential in the fabrication of diamond-based optical and photonic devices. We report here about the variation of the real part of the refractive index at lambda=632.8 nm in high quality single crystal diamond damaged with 2 and 3 MeV protons at low-medium fluences (10^13 - 10^17 ions cm^-2). After implanting the samples in 125x125 um^2 areas with a raster scanning ion microbeam, the variation of optical thickness of the implanted regions was measured with laser interferometric microscopy. The results were analyzed with a model based on the specific damage profile. The technique allows the direct fabrication of optical structures in bulk diamond based on the localized variation of the refractive index, which will be explored in future works., 15 pages, 4 figures

As demonstrated in previous works, implantation with a MeV ion microbeam through masks with graded thickness allows the formation of conductive micro-channels in diamond which are embedded in the insulating matrix at controllable depths [P. Olivero et al., Diamond Relat. Mater. 18 (5-8), 870-876 (2009)]. In the present work we report about the systematic electrical characterization of such micro-channels as a function of several implantation conditions, namely: ion species and energy, implantation fluence. The current-voltage (IV) characteristics of the buried channels were measured at room temperature with a two point probe station. Significant parameters such as the sheet resistance and the characteristic exponent (alpha) of the IV power-law trend were expressed as a function of damage density, with satisfactory compatibility between the results obtained in different implantation conditions., 19 pages, 5 figures

Space charge limited currents (SCLC) were observed on diamond surfaces that were damaged by mega-electron volt (MeV) ion implantations. The current-voltage plots display an exponential behavior with a fitting constant α, whose value was found to increase with thermal annealing temperatures up to 600oC. Comparisons among the surface areas implanted with different ion fluences indicate that there exists a damage threshold, above which the SCLC occur, and below which Ohmic conduction dominates. Raman spectroscopy studies confirm that the measured conductance originates from the vacancies created in the shallow surface layers, in agreement with Baskin's model [1]; furthermore, the spectra show that the trapped space charges could be related to the interstitials in the surface layers, which may form a localized field in opposition to the drift current flow.

Mono and polycrystalline Chemical Vapor Deposited (CVD) diamond is a promising material for several advanced topics: microchips substrate, biological applications, UV and particle detection. Commercial CVD diamonds are available in small square size, commonly 3-5 millimeters side and 0.5-1.5 millimeters thickness. To improve diamond reliability for described applications, it is important to have a quality control on diamond samples, not only for electrical constants but also for optical characteristics and surface roughness. In this paper we present an optical characterization method based on interferometric instruments, to measure surface structure and internal homogeneity of mono ad polycrystalline commercial CVD diamonds, with measurement examples.

This paper reports on the investigation of the electronic properties of a thin film CdS/CdTe solar cell with the Ion Beam Induced Charge (IBIC) technique. The device under test is a thin film (total thickness around 10 um) multilayer heterojunction solar cell, displaying an efficiency of 14% under AM1.5 illumination conditions. The IBIC measurements were carried out using focused 3.150 MeV He ions raster scanned onto the surface of the back electrode. The charge collection efficiency (CCE) maps show inhomogeneous response of the cell to be attributed to the polycrystalline nature of the CdTe bulk material. Finally, the evolution of the IBIC signal vs. the ion fluence was studied in order to evaluate the radiation hardness of the CdS/CdTe solar cells in view of their use in solar modules for space applications., Comment: 22 pages, 12 figures

In this paper, we measure the decoherence time of phonons using spectral interference of the Stokes emission of diamond. Two 100 femtosecond laser pulses, separated by a delay tau, are sent through a polished diamond sample of 1.2 mm thickness. Optical phonons in the Brillouin zone centre are created by Raman scattering from the ultrafast laser pulses and can be heralded by the Stokes photons emitted, whose superposed spectrum is recorded by a spectrometer.

Nitrogen-vacancy centers in diamond typically have spin-conserving optical transitions, a feature which allows for optical detection of the long-lived electronic spin states through fluorescence detection. However, by applying stress to a sample it is possible to obtain spin-nonconserving transitions in which a single excited state couples to multiple ground states. Here we describe two-frequency optical spectroscopy on single nitrogen-vacancy centers in a high-purity diamond sample at low temperature. When stress is applied to the sample it is possible to observe coherent population trapping with a single center. By adjusting the stress it is possible to obtain a situation in which all of the transitions from the three ground sublevels to a common excited state are strongly allowed. These results show that all-optical spin manipulation is possible for this system, and we propose that that by coupling single centers to optical microcavities, a scalable quantum network could be realized for photonic quantum information processing.

A focused ion beam is used to mill side holes in air-silica structured fibres. By way of example, side holes are introduced in two types of air-structured fibres (1) a photonic crystal four-ring fibre and (2) a 6-hole single ring step index structured fibre., Comment: 15 pages, 4 figures

A focused ion beam is used to mill side access holes in two types of silica structured fibres: (1) a four-ring photonic crystal fibre and (2) a 6-hole single ring step index structured fibre.

Coherent population trapping is demonstrated in single nitrogen-vacancy centers in diamond under optical excitation. For sufficient excitation power, the fluorescence intensity drops almost to the background level when the laser modulation frequency matches the 2.88 GHz splitting of the ground states. The results are well described theoretically by a four-level model, allowing the relative transition strengths to be determined for individual centers. The results show that all-optical control of single spins is possible in diamond., minor corrections

Coherent population trapping at zero magnetic field was observed for nitrogen-vacancy centers in diamond under optical excitation. This was measured as a reduction in photoluminescence when the detuning between two excitation lasers matched the 2.88 GHz crystal-field splitting of the color center ground states. This behavior is highly sensitive to strain, which modifies the excited states, and was unexpected following recent experiments demonstrating optical readout of single nitrogen-vacancy electron spins based on cycling transitions. These results demonstrate for the first time that three-level Lambda configurations suitable for proposed quantum information applications can be realized simultaneously for all four orientations of nitrogen-vacancy centers at zero magnetic field., Comment: 8 pages, 5 figures, new figure added

All-optical coherent population trapping is possible in nitrogen-vacancy centers in diamond at zero magnetic field. This should allow for simpler implementations of potential devices involving optical manipulation of electron spins.

At the end of range of MeV ions in diamond, black spots are created corresponding to the Bragg peak in the stopping power; the characteristics of which are not well understood but may have application in the micromachining of diamond, quantum state storage and diamond based photonic devices. This paper reports on the initial findings of studies to determine the physical properties of these buried black spots, while exploring how to optimally fabricate microstructures within the diamond. The authors have created buried 3-D structures in single crystal diamond by means of deep implantation with a focussed ion microbeam, over a wide range of fluences. Characterization is performed with confocal Raman spectroscopy.

In the last decade, the synthesis and characterization of nanometer sized carbon clusters have attracted growing interest within the scientific community. This is due to both scientific interest in the process of diamond nucleation and growth, and to the promising technological applications in nanoelectronics and quantum communications and computing. Our research group has demonstrated that MeV carbon ion implantation in fused silica followed by thermal annealing in the presence of hydrogen leads to the formation of nanocrystalline diamond, with cluster size ranging from 5 to 40 nm. In the present paper, we report the synthesis of carbon nanoclusters by the implantation into fused silica of keV carbon ions using the Plasma Immersion Ion Implantation (PIII) technique, followed by thermal annealing in forming gas (4% 2 H in Ar). The present study is aimed at evaluating this implantation technique that has the advantage of allowing high fluence-rates on large substrates. The carbon nanostructures have been characterized with optical absorption and Raman spectroscopies, cross sectional Transmission Electron Microscopy (TEM), and Parallel Electron Energy Loss Spectroscopy (PEELS). Nuclear Reaction Analysis (NRA) has been employed to evaluate the deuterium incorporation during the annealing process, as a key mechanism to stabilize the formation of the clusters.

The damage produced by 2 MeV protons on a 4H-SiC Schottky diode has been investigated by monitoring the charge collection efficiency as the function of the ion fluence. A new algorithm based on the Shockley-Ramo-Gunn theorem has been developed to interpret the experimental results. The fitting procedure provides a parameter which is proportional to the average number of active electrical traps generated by a single ion, which can be profitably used to estimate the radiation hardness of the material.

This paper presents a technique to expose and characterize nano-structured hole arrays in tapered photonic crystal fibers. Hole array structures are examined with taper outer diameters ranging from 12.9 microm to 1.6 microm. A combined focused ion beam milling and scanning electron microscope system was used to expose and characterize the arrayed air-silica structures. Results from this combined technique are presented which resolve hole-to-hole pitch sizes and hole diameters in the order of 120 nm and 60 nm, respectively.

An option of increasing the luminosity of the Large Hadron Collider (LHC) at CERN to 10^35 cm^(- 2) s(- 1) has been envisaged to extend the physics reach of the machine. An efficient tracking down to a few centimetres from the interaction point will be required to exploit the physics potential of the upgraded LHC. As a consequence, the semiconductor detectors close to the interaction region will receive severe doses of fast hadron irradiation and the inner tracker detectors will need to survive fast hadron fluences of up to above 1016 cm 2. The CERN-RD50 project ''Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders'' has been established in 2002 to explore detector materials and technologies that will allow to operate devices up to, or beyond, this limit. The strategies followed by RD50 to enhance the radiation tolerance include the development of new or defect engineered detector materials (SiC, GaN, Czochralski and epitaxial silicon, oxygen enriched Float Zone silicon), the improvement of present detector designs and the understanding of the microscopic defects causing the degradation of the irradiated detectors. The latest advancements within the RD50 collaboration on radiation hard semiconductor detectors will be reviewed and discussed in this work.

Priming by X-rays or by beta-rays is generally needed in order to qualify CVD diamond for nuclear detection or for dosimetry. The priming effect is usually attributed in filling the hole traps, which are responsible for the charge collection efficiency of the detector. Emptying the filled traps can be easily detected by Thermoluminescence (TL), which is considered to be a measure of the absorbed dose. In this work, we prove that below-gap photocurrent (BGPC) can also be used in the same way and it is dominated by the optical detrapping of holes from the same centers. Time dependence of this beta-rays induced persistent photocurrent (PPC), which in fact, depends only on the total number of photons impinging onto the sample. In fact, at long times or for large number of photons, the photocurrent approaches to the same limit of PC for a null dose. The hole trapping centers distribution seems to extend from 1.25 to 2.5 eV valence band.

Local anodic oxidation (LAO) of hydrogenated CVD diamond surfaces was carefully investigated as a function of the scanning speed, relative humidity and bias voltage. As examples, perfect control of the width of the oxidised lines between 80 and 110 nm was demonstrated for scanning speeds between 20 and 110 nm s-1, at 60% relative humidity, and between 45 and 90 nm by switching the humidity from 40% to 60%. The oxidation process is indicated by the decay of the current during the LAO process, which is concluded in about 10 s. The interpretation of the results, which in the literature oscillates between digging grooves and the creation of oxidised bumps, is still quite difficult, since it depends on the AFM mode ('contact' or 'non-contact') which was used for LAO. A true oxidation process is more likely to occur, as indicated by the present results, and this is in agreement with the presence of oxygen in surface analysis data.

Silicon carbide has recently emerged as an attractive material for ionisation radiation detection. The high band gap and high radiation damage resistance should allow the fabrication of detectors capable to operate at high temperature and in high radiation fields. The development of SiC radiation detectors in the field of spectroscopy imposes severe constraints in the electronic quality and homogeneity of the material. In this work we present an investigation of the charge collection properties of ‘detector grade’ 4H-SiC Schottky diodes performed by means of the X-ray and ion beam induced charge collection (XBICC and IBIC) techniques. Such techniques allow the minority carrier diffusion length of the material to be evaluated and mapping of the transport properties to be performed with a spatial resolution of the order of 1 μm. The investigated detectors are formed by Schottky contact (Au) on the epitaxial layer and an ohmic contact on the back side of 4H-SiC substrates. IBIC measurements were performed using protons of energy 0.7–1.7 MeV. The IBIC spectra show a complete charge collection generated by ionisation in the depletion region. Similar analysis was also performed in steady state conditions using data from photocurrent measurements carried out at European Synchrotron Radiation Facility using 3 keV photons. IBIC and XBICC maps were obtained by recording the mean pulse height and the mean photocurrent as a function of the photon or ion impact co-ordinates. The analysis of such maps allowed us to individuate the spatial distribution of defects and contact imperfections.

TRIBICC ( Time Resolved Ion Beam Induced Charge Collection ) represents a further improvement with respect to more traditional IBICC, since it can supply not only the charge collection efficiency ( and consequently data on mobility and trapping time of carriers in drift regions ), but also its time behaviour. At long collection times, it can supply informations about diffusion lenghts and lifetimes of carriers in the diffusion regions, which are always present in undepleted devices such as power devices. These data are of paramount importance as inputs for device simulation codes. A more general and more powerful TRIBICC method is presented in this work by using Gunn’s theorem and a particular formulation of the generation function in order to solve the adjoint of the continuity equation. This method represents a strong improvement with respect to a previous one, in which lateral IBIC was used. An application of this method to a commercial power device is presented and discussed. By using microbeams, life...

A combination of micro-ionoluminescence (micro-IL) and micro-PIXE was used to characterize diamond grains inside a type of meteorites known as ureilites. Ureilites are a group of achondrites unique in containing relatively large amounts of carbon occurring as diamond, graphite or lonsdaleite. A shock origin for ureilitic diamonds has been widely accepted though an exact knowledge of the conditions during high-pressure graphite conversion is not yet achieved. Micro-IL is a very powerful technique for material investigation and particularly for diamond analysis. Using this technique we were able to identify the occurrence of the diamond phase inside carbon meteoritic inclusions and to perform micro-PIXE analysis on single diamond grains. In fact, IL in low nitrogen content diamonds is dominated by A-band emission (centered at about 2.9 eV) and so, considering only IL monochromatic map at such a spectral band, it was possible to identify them. By making measurements directly on the meteorites, contamination during chemical extraction processes was avoided and it was possible to study not only the diamond phase, but also its distribution inside carbon inclusions.

We report the growth of highly oriented microscopic whisker-like crystals in the Bi–Sr–Ca–Cu–O system by means of glassy precursors. The dependence of the growth on the stoichiometric composition and on the temperature and duration of the annealing process has been studied. Chemical impurities have been investigated from the point of view of the morphology, the elemental composition and the crystal structure, identifying the presence of CuAl2O4, Sr1.2Bi0.8O3 and Al. Electrical contacts have been fabricated by means of thermal evaporation and diffusion. Their sizes have been carefully measured, achieving contact resistivity in the range of 0.2–3.7 × 10−6 Ω cm2. A very slow degrading of the contacts and the crystals on a time scale of a few years has been detected. This is associated with a decrease in Tc, which is probably due to oxygen release from the material.

Single-photon sources represent a key enabling technology in quantum optics, and single colour centres in diamond are a promising platform to serve this purpose, due to their high quantum efficiency and photostability at room temperature. The widely studied nitrogen vacancy centres are characterized by several limitations, thus other defects have recently been considered, with a specific focus of centres emitting in the Near Infra-Red. In the present work, we report on the coupling of native near-infrared-emitting centres in high-quality single crystal diamond with Solid Immersion Lens structures fabricated by Focused Ion Beam lithography. The reported improvements in terms of light collection efficiency make the proposed system an ideal platform for the development of single-photon emitters with appealing photophysical and spectral properties., Comment: 17 pages, 5 figures

We present the results of variable-angle spectroscopic ellipsometry and transmittance measurements to determine the variation of the complex refractive index of ion implanted single-crystal diamond. An increase is found in both real and imaginary parts at increasing damage densities. The index depth variation is determined in the whole wavelength range between 250 and 1690 nm. The dependence from the vacancy density is evaluated, highlighting a deviation from linearity in the high-damage-density regime. A considerable increase (up to 5%) in the real part of the index is observed, attributed to an increase in polarizability, thus offering new microfabrication possibilities for waveguides and other photonic structures in diamond., 3 pages, 4 figures

Conference of 23rd European Physical Society Conference on High Energy Physics, EPS-HEP 2015 ; Conference Date: 22 July 2015 Through 29 July 2015; Conference Code:123485; International audience; 3D pixel technology has been used successfully in the past with silicon detectors for tracking applications. Recently, a first prototype of the same 3D technology has been produced on a chemical vapour deposited single-crystal diamond sensor. This device has been subsequently tested in a beam test at CERN's SPS accelerator in a beam of 120 GeV protons. Details on the production and results of test beam data are presented.

Conference of 22nd International Workshop on Vertex Detectors, Vertex 2013 ; Conference Date: 15 September 2013 Through 20 September 2013; Conference Code:113811; International audience; We discuss the use of diamond sensors in high-energy, high-intensity collider experiments. Results from diamond sensor based beam conditions monitors in the ATLAS and CMS experiments at the CERN Large Hadron Collider (LHC) are presented and plans for diamond based luminosity monitors for the upcoming LHC run are described. We describe recent measurements on single crystal diamond sensors that indicate a polarization effect that causes a reduction of charge col- lection efficiency as a function of particle flux. We conclude by describing new developments on the promising technology of 3D diamond sensors.

Focused ion beam micromachining of long period gratings is demonstrated for the first time. Further, gratings are fabricated and characterised within both conventional step index and structured optical fibres.

Nitrogen-vacancy centers in diamond can provide a Lambda-type energy level structure with long-lived ground-state spin coherence. This talk reports progress toward demonstration of EIT in a single center coupled to an optical cavity.

International audience; At present most experiments at the CERN Large Hadron Collider (LHC) are planning upgrades in the next 5-10 years for their innermost tracking layers as well as luminosity monitors to be able to take data as the luminosity increases and CERN moves toward the High Luminosity-LHC (HL-LHC). These upgrades will most likely require more radiation tolerant technologies than exist today. As a result this is one area of intense research, and Chemical Vapour Deposition (CVD) diamond is one such technology. CVD diamond has been used extensively in beam condition monitors as the innermost detectors in the highest radiation areas of all LHC experiments. This talk describes the preliminary radiation tolerance measurements of the highest quality polycrystalline CVD material for a range of proton energies and neutrons obtained with this material with the goal of elucidating the issues that should be addressed for future diamond based detectors. The talk presents the evolution of various semiconductor parameters as a function of dose.

We experimentally demonstrate quantum enhanced resolution in confocal fluorescence microscopy exploiting the non-classical photon statistics of single nitrogen-vacancy colour centres in diamond.