Comparison of back focal plane imaging of nitrogen vacancy centers in nanodiamond and core-shell CdSe/CdS quantum dots

We report on the characterization of the angular-dependent emission of two different single-photon emitters based on nitrogen-vacancy centers in nanodiamond and on core-shell CdSe/CdS quantum dot nanoparticles. The emitters were characterized in a confocal microscope setup by spectroscopy and Hanbury-Brown and Twiss interferometry. The angular-dependent emission is measured using a back focal plane imaging technique. A theoretical model of the angular emission patterns of the 2D dipoles of the emitters is developed to determine their orientation. Experiment and model agree well with each other.

Mesa-structures and Focal Plane Arrays based on epitaxially grown InSb layers

Aspects of epitaxially grown indium antimonide (InSb) on InSb substrates (InSb-on-InSb) by molecular beam epitaxy (MBE) for the 2D focal plane arrays fabrication process have been described. The epitaxial growth offers possibility for complex structure production, and then such structures suppose more effective control of the thermal generation charge carriers as the detector temperature is raised above 80 K. Investigations of mid-wave infrared (MWIR) 320256 FPAs with 30 μm pitch and 640512 FPAs with 15 μm pitch based on InSb-on-InSb layers have shown high performance: the average detectivity at T = 77 K more than 21011 cmW-1Hz1/2, the average value of noise equivalent temperature difference (NETD) with a cold aperture of 60o at T = 77K was in the range of 10–20 mK. High quality thermal imaging images were obtained in real time mode.

SWIR Photosensory

In this paper, we report on the design, the fabrication, and performance of SWIR photomodules using sensitive two-dimensional arrays based on InGaAs-heterostructures. The de- sign of suggested InGaAs-heterostructure includes InAlAs wideband barrier layer and high sensitive absorber InGaAs layer which are increasing the uniformity and operability of focal plane array (FPA), so the number of defect elements are less than 0.5 %. The possibilities of spectral range expanding into short-wavelength to 0.5 μm and into long-wavelength to 2.2 μm regions have been considered. The operation principals of active-pulse system for 0.9–1.7 μm spectral range based on InGaAs 320256 FPA with 30 μm pitch have been presented. The investigations showed that the infrared gated-viewing system based on the InGaAs 320256 FPA provided a spatial resolution of 0,6 m.

Photonic Nanojet Generation Using Integrated Silicon Photonic Chip with Hemispherical Structures

Photonic nanojet (PNJ) is a tightly focused diffractionless travelling beam generated by dielectric microparticles. The location of the PNJ depends on the refractive index of the material and it usually recedes to the interior of the microparticle when the refractive index is higher than 2, making high index materials unsuitable to produce useful PNJs while high index favours narrower PNJs. Here we demonstrate a design of CMOS compatible high index on-chip photonic nanojet based on silicon. The proposed design consists of a silicon hemisphere on a silicon substrate. The PNJs generated can be tuned by changing the radius and sphericity of the hemisphere. Oblate spheroids generate PNJs further away from the refracting surface and the PNJ length exceeds 17𝜆 when the sphericity of the spheroid is 2.25 The proposed device can have potential applications in focal plane arrays, enhanced Raman spectroscopy, and optofluidic chips.

Multi-Lane Mirror for Broadband Applications of the Betatron X-ray Source

A new generation of small-scale ultrafast X-ray sources is rapidly emerging. Laser-driven betatron radiation represents an important class of such ultrafast X-ray sources. With the sources driving towards maturity, many important applications in material and biological sciences are expected to be carried out. While the last decade mainly focused on the optimization of the source properties, the development of such sources into user-oriented beamlines in order to explore the potential applications has recently taken off and is expected to grow rapidly. An important aspect in the realization of such beamlines will be the implementation of proper X-ray optics. Here, we present the design of a multi-lane X-ray mirror as a versatile focusing device covering a wide spectral range of betatron X-rays. The expected photon flux in the focal plane of such optics was also estimated through geometrical simulations.