Non-contact polishing of single crystal diamond by ion beam etching

We propose a non-contact surface finishing method for brittle substrates by ion beam etching and we experimentally demonstrate polishing of (100) single crystal diamond surface. We model and simulate the polishing process, and verify the results experimentally by monitoring individual defects during the surface treatment. Rapid flattening of scratches and digs, as typically present on brittle substrates after mechanical polishing, is observed: trench depth is typically removed by 95% in less than 30 min. The polishing method relies on physical bombardment of the substrate surface with accelerated inert gas ions, rendering it highly versatile and applicable to a wide variety of materials

Diamond diffractive optics-recent progress and perspectives

Diamond is an exceptional material that has recently seen a remarkable increase in interest in academic research and engineering since high-quality substrates became commercially available and affordable. Exploiting the high refractive index, hardness, laser-induced damage threshold, thermal conductivity and chemical resistance, an abundance of applications incorporating ever higher-performance diamond devices has seen steady growth. Among these, diffractive optical elements stand out-with progress in fabrication technologies, micro- and nano-fabrication techniques have enabled the creation of gratings and diffractive optical elements with outstanding properties. Research activities in this field have further been spurred by the unique property of diamond to be able to host optically active atom scale defects in the crystal lattice. Such color centers allow generation and manipulation of individual photons, which has contributed to accelerated developments in engineering of novel quantum applications in diamond, with diffractive optical elements amidst critical components for larger-scale systems. This review collects recent examples of diffractive optical devices in diamond, and highlights the advances in manufacturing of such devices using micro- and nano-fabrication techniques, in contrast to more traditional methods, and avenues to explore diamond diffractive optical elements for emerging and future applications are put in perspective

Integrated photonic devices in single crystal diamond

The field of diamond photonics is reviewed, with a focus on recent experimental demonstrations of photonic integrated devices in a single crystal diamond. This field leverages the outstanding material properties of diamond with the aim to establish large-scale integrated photonics for applications in sensing, information and communication technologies, and optomechanics. Accordingly, this review introduces recent progress in scalable micro- and nano-fabrication techniques for single crystal diamond photonic integrated devices, and provides quantitative comparative evaluation of the performance of the state of the art devices. The review concludes with an outlook of the potential of photonic integrated circuits in single crystal diamond

Enhancement of optical quality factor by thermal annealing of single crystal diamond micro-resonators

We report on the increase in optical quality factor of a suspended single crystal diamond micro-disk resonator by thermal annealing. The resonators are fabricated by Deep Reactive Ion Etching (DRIE) to obtain circular pillars in bulk single crystal diamond, followed by multidirectional Focused Ion Beam (FIB) milling to shape the anchor, thin the micro disk and smooth the sidewalls. Thermal annealing in air at 500 degrees C for 4 h eliminates FIB induced crystal damage yielding optical quality factors of up to 5'700, corresponding to an increase of up to 5x compared to the resonators before annealing

Single crystal diamond micro-disk resonators by focused ion beam milling

We report on single crystal diamond micro-disk resonators fabricated in bulk chemical vapor deposition diamond plates (3 mm × 3 mm × 0.15 mm) using a combination of deep reactive ion etching and Focused Ion Beam (FIB) milling. The resulting structures are micro-disks of few μm in diameter and less than 1 µm thick, supported by a square or diamond section pillar resulting from the multi-directional milling. Thin aluminum and chromium layers are used to ground the substrate, limit the ion implantation, and prevent edge rounding and roughening. FIB damage is then removed by a combination of hydrofluoric acid etching, oxygen plasma cleaning, and annealing at 500 °C for 4 h in air. We experimentally characterize the optical behavior of the devices by probing the transmission of a tapered fiber evanescently coupled to the micro-disk, revealing multiple resonances with a quality factor up to 5700 in the S- and C-band