Abstract. The field of plasmonics has the potential to enable unique applications in the midinfrared (IR) wavelength range. However, as is the case regardless of wavelength, the choice of plasmonic material has significant implications for the ultimate utility of any plasmonic device or structure. In this manuscript, we review the wide range of available plasmonic and phononic materials for mid-IR wavelengths, looking in particular at transition metal nitrides, transparent conducting oxides, silicides, doped semiconductors, and even newer plasmonic materials such as graphene. We also include in our survey materials with strong mid-IR phonon resonances, such as GaN, GaP, SiC, and the perovskite SrTiO 3 , all of which can support plasmon-like modes over limited wavelength ranges. We will discuss the suitability of each of these plasmonic and phononic materials, as well as the more traditional noble metals for a range of structures and applications and will discuss the potential and limitations of alternative plasmonic materials at these IR wavelengths.

Owing to their ability to generate non‐classical light states, quantum dots (QDs) are very promising candidates for the large‐scale implementation of quantum information technologies. However, the high photon collection efficiency demanded by these technologies may be impossible to reach for “standalone” semiconductor QDs, embedded in a high‐refractive index medium. In this work a novel laser writing technique is presented, enabling the direct fabrication of a QD self‐aligned—with a precision of ±30 nm—to a dielectric microsphere. The presence of the microsphere leads to an enhancement of the QD luminescence collection by a factor 7.3 ± 0.7 when an objective with 0.7 numerical aperture is employed. This technique exploits the possibility of breaking the N−H bonds in GaAs1−xNx:H by a laser light, obtaining a lower‐bandgap material, GaAs1−xNx. The microsphere, deposited on top of a GaAs1−xNx:H/GaAs quantum well, is used to generate a photonic nanojet, which removes hydrogen exactly below the microsphere, creating a GaAs1−xNx QD at a predefined distance from the sample surface. Second‐order autocorrelation measurements confirm the ability of the QDs obtained with this technique to emit single photons.

In recent years, dielectric microspheres have been used in conjunction with optical microscopes to beat the diffraction limit and to obtain super-resolution imaging. We investigate, for the first time, the use of microspheres on quantum dots (QDs) to enhance the light coupling efficiency. We demonstrate the enhancement of the QD luminescence collection in terms of extraction and directionality, as well as the enhancement of spatial resolution. In particular, we find that a dielectric microsphere, placed on top of an epitaxial QD, increases the collected radiant energy by about a factor of 42, when a low numerical aperture objective is used. Moreover, if two or more QDs are present below the microsphere, the modification of the far field emission pattern allows selective collection of the luminescence from a single QD by simply changing the collection angle. Dielectric microspheres present a simple and efficient tool to improve the QD spectroscopy, and potentially QD based devices.

No abstract

The purpose of this study was to assess the effectiveness of computer-aided orthognathic surgery in reducing incisal overjet and establishing class I occlusion in subjects with dentofacial deformities. To address the research purpose, the investigators initiated a retrospective cohort study and enrolled a sample of subjects who underwent computer-assisted orthognathic surgery for dentofacial deformities. Two examiners assessed preoperative and postoperative lateral cephalometric radiographs for change in overjet after computer-assisted orthognathic surgery. Preoperative and postoperative occlusal photographs were then reviewed to assess for establishment of class I occlusion after computer-assisted orthognathic surgery. Cohen κ coefficient was used to assess for interrater agreement. A matched-pairs t-test was used to assess reduction in incisal overjet after computer-assisted orthognathic surgery. The sample was composed of 9 subjects who underwent computer-assisted surgery for dentofacial deformities. There was good interrater consistency for preoperative measurement of overjet (κ = 0.7, P ≤ 0.001). There was fair interrater consistency for postoperative measurement of overjet (κ = 0.4, P = 0 .02). Both examiners agreed on preoperative and postoperative assessments of occlusal photographs. There was a 3.4-mm reduction in incisal overjet after computer-assisted orthognathic surgery (P ≤ 0.001). Mean postoperative absolute overjet was 1.3 mm. In subjects with dentofacial deformities, computer-aided orthognathic surgery was effective in reducing incisal overjet and establishing class I occlusion.