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[en] Nonlinear dynamic characteristics of a 1550 nm vertical-cavity surface-emitting laser (1550 nm VCSEL) simultaneously subject to orthogonal optical injection and negative optoelectronic feedback are experimentally investigated. The results show that, under suitable orthogonal optical injection the VCSEL can exhibit rich nonlinear dynamic behaviors such as stable state (S), period-one (P1), period-two (P2), chaos (CO), stable injection locking (SIL) and polarization switching (PS). After further introducing negative optoelectronic feedback with a certain feedback delay time, the dynamic distribution of the orthogonal optical injection 1550 nm VCSEL is significantly affected, and some new phenomena including three-frequency quasiperiodic (Q3) state can be observed. With the increase of optoelectronic feedback strength, the S and SIL regions typically are shrank, while the quasiperiodic (QP) and CO regions are enlarged. (paper)
[en] Electronic Speckle Pattern Interferometry, a non-contact and nondestructive optical diagnostic technique, was employed for evaluating the conservation state of a XVI century painting on wood. The whole structure alterations, induced by the laboratory temperature and relative humidity variations, were evaluated. Long-term analysis, by sequential recording and subsequent off-line processing of the fringes progression, was carried out. Local flaws and hidden detachments of pictorial layers from the support, which could not be recognized by traditional art-restorer survey methods, were also easily revealed. In such a case, a simple measurement approach was utilized, with the aim to get a user-friendly method for art conservators. The results demonstrate that the interferometry method can largely improve the traditional art conservation survey techniques.
[en] The task of matching image of an object with its template is central for many optoelectronic systems. Solution of the matching problem in three-dimensional space in contrast to the structural alignment in the image plane allows using a larger amount of information about the object for determining its orientation, which may increase the probability of correct matching. In the case of stereo vision methods for constructing a three-dimensional image of the object, it becomes possible to achieve invariance w.r.t. background and distance to the observed object. Only three of the orientation angle of the object relative to the camera are uncertain and require measurements. This paper proposes a method for determining the orientation angles of the observed object in three-dimensional space, which is based on the processing of stereo image sequences. Disparity map segmentation method that allows one to ensure the invariance of the background is presented. Quantitative estimates of the effectiveness of the proposed method are presented and discussed.
[en] Development of technology for processing of surfaces by means of gas cluster ion beams began only about a quarter century ago even though fundamental research related to generation of gas clusters began much earlier. Industrial applications of cluster ion beams did not start to be explored until commercial equipment was first introduced to the ion beam community in around 2000. The technology is now evolving rapidly with industrial equipment being engineered for many diverse surface processing applications which are made possible by the unique characteristics of cluster-ion/solid-surface interactions. In this paper, important historical milestones in cluster ion beam development are described. Present activities related to a wide range of industrial applications in semiconductors, magnetic and optical devices, and bio-medical devices are reviewed. Several emerging new advances in cluster beam applications for the future are also discussed
[en] We design and fabricate a parallel system with 10 high speed side-illuminated evanescently coupled waveguide photodetectors (ECPDs). The 10 ECPDs exhibit a uniform 3 dB bandwidth of 20 GHz and low dark current of about 1 nA at 2 V reverse bias. The 10 ECPDs also exhibit uniform photo-responsivity of about 0.23 A/W with an active region of 5 × 25 μm"2. The photodetector array has a total bandwidth of more than 200 GHz and can be integrated with other optoelectronic devices. (paper)
[en] Organic optoelectronic devices, such as light-emitting diodes, organic solar cells (OSCs), and organic field effect transistors (OFETs), have emerged due to the development of π-conjugated polymers. Because the delocalized π-framework can significantly reduce the energy gap between the highest-occupied molecular orbital (HOMO) and the lowest-unoccupied molecular orbital (LUMO), their intrinsic optoelectronic properties can be tunable with their conjugation length in terms of average molecular weights and their π-backbone structures. The new type of low bandgap conjugated polymer (P1) has been successively polymerized via a palladium- catalyzed Stille cross-coupling reaction with bis-ethylhexyl BDT and bis-n-decane DPP. With a linear alkyl chain in the DPP units, the intermolecular packing structure was thought to be enhanced by proving the UV–Vis and UPS spectra. In addition, the electronic properties of P1 via field-effect transistors well illustrate the typical p-type semiconducting property without showing the significant improvement by thermal annealing. From a broader perspective, this research indicates that a wider choice of linear alkyl chain length in DPP units and modification of the interface between dielectric and active layers should be sought to further optimize device performance. Hence, progressive works with the strategy presented in this report will be pursued to address the different challenges in attaining target OFET performances.
[en] Highlights: • We have designed Universal Interface on Zynq"® SoC with CAN, RS-232, Ethernet and AXI GPIO for Instrumentation & Control. This project is based on Zynq"®-7000 family xc7z020clg484-1 chip. • We explored the full design flow starting from the hardware development in Vivado to software development in SDK using APIs in C language and then interfacing the host application developed in LabVIEW. • We also explored how to make custom IP with AXI bus interface in Vivado. • Useful for those who wants to make custom hardware on Zynq"® SoC. - Abstract: This paper describes an application developed on the latest Zynq"®-7000 All Programmable SoC (AP SoC)  devices which integrate the software programmability of an ARM"®-based processor with the hardware programmability of an FPGA, on a single device. In this paper we have implemented application which uses various interfaces like CAN, RS-232, Ethernet and AXI GPIO, so that our host application running on PC in LabVIEW can communicates with any hardware which has at least any one of the available interface. Zynq-7000 All Programmable SoCs (System On Chip) infuse customizable intelligence into today’s embedded systems to suit your unique application requirements. This family of FPGA is meant for high end application because it has huge resources on single chip. It offers you to make your own custom hardware IP, in fact we have made our custom IP called myIP in our design. The beauty of this chip is that it can write drivers for your custom IP which has AXI bus layer attached. After exporting the hardware information to the Software Development Kit (SDK), the tool is able to write drivers for your custom IP. This simplifies your development to a great extent. In a way this application provides the universal interfacing option to user. User can also write the digital data on the GPIO (General Purpose Input Output) through LabVIEW Test application GUI. This project can be used for remote control and monitor the data over Ethernet or CAN network.
[en] We report a new method for reconstructing the signal shape of the external dynamic perturbations along the entire length of the fibre of an optical coherence reflectometer. The method proposed is based on differential phase-shift keying of a probe pulse and demodulation of scattered light by the phase diversity technique. Possibilities of the method are demonstrated experimentally. (fibre-optic sensors)
[en] In my research group, we are developing Ionic Liquid (IL) based green synthesis to prepare next generation phosphor materials for energy efficient and environmentally lighting; rare-earth based optoelectronic materials with improved property or property combinations. Here we are not only using ionic liquids as templating agent, solvent but also sometimes as a reaction partner i.e. three in one. In addition, we are also developing new generation semiconducting materials for removing toxic dyes released to the water bodies by industries specially textile industries. Keeping in mind about the fascinating applications of our smart materials our endeavor is also to unravel the structure property relationship controlled by tuning ionic liquid properties. Brief of the two topics which will be discussed here are given below. (author)
[en] Magnetic inertial measurement unit systems (MIMU) offer the potential to perform joint kinematics evaluation as an alternative to optoelectronic systems (OS). Several studies have reported the effect of indoor magnetic field disturbances on the MIMU's heading output, even though the overall effect on the evaluation of lower limb joint kinematics is not yet fully explored. The aim of the study is to assess the influence of indoor magnetic field distortion on gait analysis trials conducted with a commercial MIMU system. A healthy adult performed gait analysis sessions both indoors and outdoors. Data collected indoors were post-processed with and without a heading correction methodology performed with OS at the start of the gait trial. The performance of the MIMU system is characterized in terms of indices, based on the mean value of lower limb joint angles and the associated ROM, quantifying the system repeatability. We find that the effects of magnetic field distortion, such as the one we experienced in our lab, were limited to the transverse plane of each joint and to the frontal plane of the ankle. Sagittal plane values, instead, showed sufficient repeatability moving from outdoors to indoors. Our findings provide indications to clinicians on MIMU performance in the measurement of lower limb kinematics. (paper)