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We present a model of a tunable distributed Bragg reflector (DBR) laser describing the effect of cavity losses on the gain voltage. Theoretical and experimental results are in good agreement. Measurements show the gain voltage trace for Bragg grating and phase section tuning. The model is also valid for lasers with optical feedback from an external reflection.

Die vaskularen Demenzen (VD; aufgrund der verschiedenen Auspragungen von VD wird im vorliegenden Beitrag die Mehrzahl verwendet) stellen nach der Alzheimer-Demenz die zweithaufigste Demenzform dar und spielen besonders bei geriatrischen Patienten eine wichtige Rolle. Vaskulare Demenzen konnen nach akuten Situationen (z. B. durch Schlaganfalle) und durch langsam fortschreitende vaskulare Schadigungen auftreten. Im vorliegenden Beitrag werden VD aufgrund von kortikalen und strategischen Infarkten, von mikroangiopathischen Infarkten mit Lakunen sowie von Blutungen genauer dargestellt. Dabei werden neben der klinischen Beschreibung beispielhafte radiologische Befund gezeigt sowie ein besonderes Augenmerk auf Edukation, Pravention und Rehabilitation gelegt.

The aim of this continuing medical education (CME) article (part II) is to describe the particular challenge of the treatment of hyponatremia, which occurs in older patients. This part II follows on from part I concerning the diagnosis in the previous volume. A staged approach is necessary. The best treatment is always when the underlying cause can be eliminated. Hyponatremia in older patients is mainly induced by the syndrome of inappropriate antidiuretic hormone (SIADH) secretion. The authors use a concept for the first, second and third line strategy: (1) changing or discontinuation of drugs, (2) fluid restriction and (3) tolvaptan medication. The algorithm for treatment should be simple. It also contains recommendations for the correction rate. Caution is also needed in order to avoid the occurrence of an osmotic demyelination syndrome (ODS).

Geriatric medicine is a rapidly evolving field that addresses diagnostic, therapeutic and care aspects of older adults. Some disabilities and disorders affecting cognition (e.g. dementia), motor function (e.g. stroke, Parkinson’s disease, neuropathies), mood (e.g. depression), behavior (e.g. delirium) and chronic pain disorders are particularly frequent in old subjects. As knowledge about these age-associated conditions and disabilities is steadily increasing, the integral implementation of neurogeriatric knowledge in geriatric medicine and specific neurogeriatric research is essential to develop the field. This article discusses how neurological know-how could be integrated in academic geriatric medicine to improve care of neurogeriatric patients, to foster neurogeriatric research and training concepts and to provide innovative care concepts for geriatric patients with predominant neurological conditions and disabilities.

In this paper we explain how to use rate equations to describe a laser that includes integrated optical feedback. We find a relation between the threshold current, the voltage drop at the gain section, output power, linewidth, and side mode suppression ratio, and show experimental results.

In this paper we demonstrate the feasibility of low cost lasers with an integrated wavelength locker and wavelength meter. We use a reflection at the polymer chip to single mode fiber butt coupling point to establish optical feedback outside the laser cavity to make the gain voltage wavelength dependent. With this signal we can keep the alignment of the lasing mode and the Bragg grating optimal and can determine the absolute wavelength of the emitted wavelength without additional hardware.

Three therapeutic applications are presently prescribed in the radon spas in Gastein, Austria: exposure to radon in a thermal bath, exposure to radon vapor in an exposure chamber (vapor bath), and exposure to radon in the thermal gallery, a former mine. The radiological exposure pathways to human organs and tissues in these therapeutic radon applications are inhalation of radon and radon progeny via the lungs, radon transfer from water or air through the skin, and radon-progeny deposition on the skin in water or air. The objectives of the present study were to calculate radon and radon-progeny doses for selected organs and tissues for the different exposure pathways and therapeutic applications. Doses incurred in red bone marrow, liver, kidneys, and Langerhans cells in the skin may be correlated with potential therapeutic benefits, while doses to the lungs and the basal cells of the skin indicate potential carcinogenic effects. The highest organ doses among the three therapeutic applications were produced in the thermal gallery by radon progeny via inhalation, with lung doses of 5.0 mSv, and attachment to the skin, with skin doses of 4.4 mSv, while the radon contribution was less significant. For comparison, the primary exposure pathways in the thermal bath are the radon uptake through the skin, with lung doses of 334 μSv, and the radon-progeny attachment to the skin, with skin doses of 216 μSv, while the inhalation route can safely be neglected.

This paper presents the design, fabrication, and characterization of a middle-infrared (MIR) linear variable optical filter (LVOF) and thermopile detectors that will be used in a miniaturized mixed gas detector for CH4/CO2/CO measurement. The LVOF was designed as a tapered-cavity Fabry-Pérot optical filter, which can transform the MIR continuous spectrum into multiple narrow band-pass spectra with peak wavelength in linear variation. Multi-layer dielectric structures were used to fabricate the Bragg reflectors on the both sides of tapered cavity as well as the antireflective film combined with the function of out-of-band rejection. The uncooled thermopile detectors were designed and fabricated as a multiple-thermocouple suspension structure using micro-electro-mechanical system technology. Experimentally, the LVOF exhibits a mean full-width-at-half-maximum of 400 nm and mean peak transmittance of 70% at the wavelength range of 2.3~5 μm. The thermopile detectors exhibit a responsivity of 146 μV/°C at the condition of room temperature. It is demonstrated that the detectors can achieve the quantification and identification of CH4/CO2/CO mixed gas.

A traversal algorithm considering both of the mesa interval and the entire area of the mesas was applied to find a vertical cavity surface emitting laser (VCSEL) array with minimal heat coupling factor. An optimized array was obtained and modeled in finite element software to simulate the thermal distribution. A conventional circular and an optimized array were fabricated. The maximum output power of optimized array is 14.3% higher than the conventional array and reaches 1.6 W operating in continuous wave (CW) mode. The wavelength shift of optimized VCSEL array is slightly slower than the reference device although its higher power.

Polarization-stable vertical-cavity surface-emitting lasers (VCSELs) with a simple fabrication process are presented. The gratings fixing the polarization are defined by a two-step exposure technology taking advantage of the displacement Talbot lithography technique. This enables grating lines to remain within the inner circle mesa of the VCSELs. These surface grating VCSELs with different periods are theoretically modeled and experimentally verified. Most of these VCSELs exhibit full polarization stability as predicted theoretically. For VCSELs with grating periods larger than the emission wavelength we found a weak orthogonal polarization suppression ratio, thereby deviating from those grating VCSELs with smaller periods.

Optical feedback has an impact on the tunability of lasers. We created a model of a tunable distributed Bragg reflector (DBR) laser describing the effect of optical feedback from a constant reflector distance on the wavelength tuning. Theoretical and experimental results are in good agreement. A further discussion of the model sheds light on design rules to reduce the effect of optical feedback on the tuning behavior. We introduced a new parameter called mode loss difference (MLD) as a metric for the feedback tolerance of the tuning behavior. A large MLD indicates higher tolerance of the laser to cavity length variations.

In this paper, we demonstrated vertical-cavity surface-emitting laser (VCSEL) arrays with improved thermal stability by arranging the mesa distribution within the array in a nonlinear configuration. Based on our traversal design algorithm, VCSEL arrays with inhomogeneous mesa-distances were realized. The effects of this rearrangement of mesas on the VCSEL array's thermal stability were studied experimentally. Power–current characteristics and spectra of the 808 nm VCSEL arrays with different mesa distributions were obtained under different thermal stresses in which the optimized devices showed improved performance. The experimental results prove that our algorithm-based optimization is instructive for VCSEL array design.

We propose a vertical-cavity surface-emitting laser (VCSEL) with two transverse modes independently controlled by two contacts. By directly etching a trench in the p-doped distributed Bragg reflector, we form an air gap and two sub-mesas as waveguides above the oxide layer. Contacts are deposited on each sub-mesa. Emission control on two different spatial modes in a single VCSEL is achieved by changing the driving condition of one-contact or two-contact injection. Owing to this feature, the proposed VCSEL has a potential as a cost-effective source for optical communications using spatial-division multiplexing.

The incidence of spondylodiscitis is increasing and attributable to an aging population with multimorbidities. Spondylodiscitis represents a life-threatening disease. Typical clinical manifestations often involve nonspecific symptoms with back pain; however, due to the frequent absence of fever the disease is often overlooked. Pathogen detection and spinal imaging with magnetic resonance imaging (MRI) are essential for the diagnosis. Identification of the causative pathogen is particularly important for initiating targeted antibiotic treatment. Debridement and stabilization are the mainstays of surgical management, even though foreign material must be implanted into the focus of inflammation.

In this paper, we report on high beam quality vertical-cavity surface-emitting lasers (VCSELs) featuring a monolithically integrated aspherical microlens. This lens is fabricated by a one-step diffusion-limited wet etch process. VCSELs with microlenses with different curvature radius are designed, fabricated, and characterized, as well as reference VCSEL devices without the microlens. Significant improvement of beam divergence and single-mode performance are demonstrated in microlens VCSELs. The divergence angles of a conventional VCSEL are ${\text{14.5}}$ °, $16.0$ °, and $17.0$ ° (full width at D4 $\sigma$ ) at 2 mA, 3 mA, and 4 mA, respectively, with a $M^2$ value measured to be 6.9 at 3 mA. Under the same current injection, the divergence angles of a comparable VCSEL with a micro-lens (curvature radius of 31.8 $\mu$ m) are reduced to $4.8$ °, $5.5$ °, and $5.7$ °, respectively. The $M^2$ value of the lensed VCSEL is as low as 1.9 at 3 mA.

To establish highly performing vertical cavity surface-emitting lasers (VCSELs), it is essential to have an adequate understanding of the intrinsic laser dynamics of these devices. However, this is done while bearing in mind that extrinsic parasitic elements in VCSELs play an important role in limiting the intrinsic modulation bandwidth. In this paper, we analyse different electrical parasitic equivalent circuit models in the aim of comparing them and selecting the one that can best describe and represent the physical properties of our high-performance VCSELs. Through measuring the microwave reflection coefficient $\mathrm{S}_{11}(\mathrm{f})$ and fitting it into the calculated counterpart from the equivalent-circuit impedance model, the parasitic components of the equivalent circuit model are extracted.

In this paper, we present a high-performance self-powered ultraviolet (UV) photodetector using electrochemical micro-porous-channel arrays based on a cost-effective and environment-friendly black TiO 2 nanotube arrays (BTNAs) and polysulfide (S2-/S x 2-) electrolyte. By self-doping TiO 2 the concentration and lifetime of UV photo-generated carriers are increased due to increasing oxygen vacancies and Ti3+ defects in BTNAs, effectively enhancing the carrier transport and multiple exciton effect of carriers, and thus the self-powered UV photodetector based on electrochemical micro-porous-channel arrays demonstrates a high photoresponsivity of ~22 mA/W and high-speed photoresponse of ~4 ms in rise and decay time.

We report a self-powered ultraviolet (UV) photo- detector (PD) utilizing two sets of free-standing ZnO nanorod arrays (ZNRAs) to assemble as a face-to-face nanohybrid structure. In comparison with the PDs based on single-side ZNRAs, the face-to-face ZNRAs based PD exhibits "1+1>2"enhancements in photoelectric conversion. The ZNRAs were prepared on ITO/glass and Ti foil using a facile hydrothermal method. The face-to-face ZNRAs device operates with the Schottky junctions in ITO/ZnO interface, ohmic contact in Ti/ZnO interface, and the effective NR-NR contacts in neighboring ZNRs as a transport network of carriers. Thanks to the Schottky and NR-NR junction barriers, the electron-hole pairs are effectively separated. The device exhibits a self-powered current density of 5.52 μA•cm−2 and a responsivity of 1.81 mA•W-1 under an irradiation of 3.06 mW•cm-2, and a photogain of 0.80% at photon absorption rate of 5.6×1015 s-1. It is considered that face-to-face ZNRAs could be a promising candidate for high-efficiency photo-detection.

Basal and secretory cell doses in the different lobes of the human lung following inhalation of short-lived radon progeny were calculated for a five-lobe asymmetric, stochastic lung model, considering the non-uniform ventilation of the lobes. Dose calculations for defined exposure conditions revealed that the upper lobes receive higher doses than the average bronchial dose for the whole lung, with the right upper lobe receiving the highest dose. The resulting inter-lobar distribution of cellular bronchial doses indicated that the non-uniform lung morphometry is the dominating factor, while non-uniform ventilation only slightly enhances the lobar differences. The comparison of average lobe-specific bronchial doses with the average bronchial dose for the whole lung allows the calculation of lobe-specific dose weighting factors, which can be used to convert average bronchial doses based on symmetric airway generation or bronchial compartment models to lobar bronchial doses.

Inhalation of short-lived radon progeny is an important cause of lung cancer. To characterize the absorbed doses in the bronchial region of the airways due to inhaled radon progeny, mostly regional lung deposition models, like the Human Respiratory Tract Model (HRTM) of the International Commission on Radiological Protection, are used. However, in this model the site specificity of radiation burden in the airways due to deposition and fast airway clearance of radon progeny is not described. Therefore, in the present study, the Radact version of the stochastic lung model was used to quantify the cellular radiation dose distribution at airway generation level and to simulate the kinetics of the deposited radon progeny resulting from the moving mucus layer. All simulations were performed assuming an isotope ratio typical for an average dwelling, and breathing mode characteristic of a healthy adult sitting man. The study demonstrates that the cell nuclei receiving high doses are non-uniformly distributed within the bronchial airway generations. The results revealed that the maximum of the radiation burden is at the first few bronchial airway generations of the respiratory tract, where most of the lung carcinomas of former uranium miners were found. Based on the results of the present simulations, it can be stated that regional lung models may not be fully adequate to describe the radiation burden due to radon progeny. A more realistic and precise calculation of the absorbed doses from the decay of radon progeny to the lung requires deposition and clearance to be simulated by realistic models of airway generations.

The proportion of patients with functional movement disorders (FMD) is particularly high in neurology clinics. Treatment options have not been consistently developed, not well evaluated and not validated. This article presents the preliminary data on the prevalence and treatment response of patients with FMD who were treated within the framework of an early rehabilitative geriatric complex treatment at a university hospital for neurology. From July 2017 to November 2018 the prevalence, demographic and clinical parameters, and response to treatment of FMD patients were documented and compared to non-FMD patients treated at the neurogeriatric ward of the University Hospital Schleswig-Holstein, in Kiel. Clinical endpoints were the Short Physical Performance Battery (SPPB) for mobility and the Barthel index for instrumented activity of daily life (iADL). The prevalence of FMD was 11% (19/175) and predominantly observed in women (74%). Of the FMD patients nine also had a diagnosis of either idiopathic Parkinson’s disease (N = 7), dementia with Lewy bodies (N = 1) or progressive supranuclear palsy (N = 1). At admission, neither the SPPB nor the iADL differed significantly between FMD and non-FMD patients. The treatment response was comparable between the groups: SPPB change was +0.3±1.8 (mean, standard deviation) in FMD and +0.4±1.9 in non-FMD patients (p = 0.83). The iADL change was +19±15 in FMD and +18±17 in non-FMD (p = 0.83). The prevalence of FMD was unexpectedly high in the neurogeriatric ward of a German university hospital. There were comparable impairments and responses to multidisciplinary treatment in mobility and iADL between FMD and non-FMD geriatric patients, suggesting that specific and informed treatment provided by a multidisciplinary geriatric team is effective in geriatric FMD patients. Further studies of this underdiagnosed disorder in older age are warranted.

This chapter deals with the application of Vertical-Cavity Surface-Emitting Lasers (VCSELs) as directly-modulated light-sources in optical interconnects. It shows that VCSEL-based optical interconnects are going to replace the conventional copper-based technology. VCSELs can deliver higher bandwidths below the cost of copper and enable highly scalable solutions with their small footprint. If lasers have to provide excellent beam quality at low cost and energy-consumption, VCSELs are the current technology of choice. Directly modulated VCSELs have bandwidth limitations that must be conquered to enable the highest bandwidths at ultra-low cost. The High-Speed, Temperature-Stable 980-nm VCSELs made at the Center of Nanophotonics at the Technical University of Berlin were processed in a coplanar low-parasitic ground-signal-ground contact pad layout incorporating thick BCB passivation layers. VCSELs designed to work at ultra-high bit rates don’t automatically get more energy efficient just by simply reducing the pumping current and the bit rate.

The Cherenkov Telescope Array (CTA) is the major next-generation observatory for ground-based very-high-energy gamma-ray astronomy. It will improve the sensitivity of current ground-based instruments by a factor of five to twenty, depending on the energy, greatly improving both their angular and energy resolutions over four decades in energy (from 20 GeV to 300 TeV). This achievement will be possible by using tens of imaging Cherenkov telescopes of three successive sizes. They will be arranged into two arrays, one per hemisphere, located on the La Palma island (Spain) and in Paranal (Chile). We present here the optimised and final telescope arrays for both CTA sites, as well as their foreseen performance, resulting from the analysis of three different large-scale Monte Carlo productions.© 2019, We gratefully acknowledge financial support from the following agencies and organizations: State Committee of Science of Armenia, Armenia; The Australian Research Council, Astronomy Australia Ltd, The University of Adelaide, Australian National University, Monash University, The University of New South Wales, The University of Sydney, Western Sydney University, Australia; Federal Ministry of Science, Research and Economy, and Innsbruck University, Austria; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Fundacao de Amparo a Pesquisa do Estado do Rio de Janeiro (FAPERJ), Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Ministry of Science, Technology, Innovations and Communications (MCTIC), Brasil; Ministry of Education and Science, National RI Roadmap Project D01-153/28.08.2018, Bulgaria; The Natural Sciences and Engineering Research Council of Canada and the Canadian Space Agency, Canada; CONICYT-Chile grants PFB-06, FB0821, ACT 1406, FONDECYT-Chile grants 3160153, 3150314, 1150411, 1161463, 1170171, Pontificia Universidad Catolica de Chile Vice-Rectory of Research internationalization grant under MINEDUC agreement PUC1566, Chile, Croatian Science Foundation, Rudjer Boskovic Institute, University of Osijek, University of Rijeka, University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, University of Zagreb, Faculty of Electrical Engineering and Computing, Croatia; Ministry of Education, Youth and Sports, MEYS LM2015046, LTT17006 and EU/MEYS CZ.02.1.01/0.0/0.0/16_013/0001403, CZ.02.1.01/0.0/0.0/17_049/0008422, Czech Republic; Ministry of Higher Education and Research, CNRS-INSU and CNRS-IN2P3, CEA-Irfu, ANR, Regional Council Ile-de France, Labex ENIGMASS, OSUG2020, P210 and OCEVU, France; Max Planck Society, BMBF, DESY, Helmholtz Association, Germany; Department of Atomic Energy, Department of Science and Technology, India; Istituto Nazionale di Astrofisica (INAF), Istituto Nazionale di Fisica Nucleare (INFN), MIUR, Istituto Nazionale di Astrofisica (INAF-OABRERA) Grant Fondazione Cariplo/Regione Lombardia ID 2014-1980/RST_ERC, Italy; ICRR, University of Tokyo, JSPS, MEXT, Japan; Netherlands Research School for Astronomy (NOVA), Netherlands Organization for Scientific Research (NWO), Netherlands; University of Oslo, Norway; Ministry of Science and Higher Education, DIR/WK/2017/12, the National Centre for Research and Development and the National Science Centre, UMO-2016/22/M/ST9/00583, Poland; Slovenian Research Agency, Slovenia, grants P1-0031, P1-0385, 10-0033, J1-9146; South African Department of Science and Technology and National Research Foundation through the South African Gamma-Ray Astronomy Programme, South Africa; MINECO National R+D+I, Severo Ochoa, Maria de Maeztu, CDTI, PAIDI, UJA, FPA2017-90566-REDC, Spain; Swedish Research Council, Royal Physiographic Society of Lund, Royal Swedish Academy of Sciences, The Swedish National Infrastructure for Computing (SNIC) at Lunarc (Lund), Sweden; Swiss National Science Foundation (SNSF), Ernest Boninchi Foundation, Switzerland; Durham University, Leverhulme Trust, Liverpool University, University of Leicester, University of Oxford, Royal Society, Science and Technology Facilities Council, UK; U.S. National Science Foundation, U.S.Department of Energy, Argonne National Laboratory, Barnard College, University of California, University of Chicago, Columbia University, Georgia Institute of Technology, Institute for Nuclear and Particle Astrophysics (INPAC-MRPI program), Iowa State University, the Smithsonian Institution, Washington University McDonnell Center for the Space Sciences, The University of Wisconsin and the Wisconsin Alumni Research Foundation, USA. The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreements no 262053 and no 317446. This project is receiving funding from the European Union's Horizon 2020 research and innovation programs under agreement no 676134.

A microspectrometer based on a middle-infrared (Mid-IR) linear variable optical filters (LVOF) and a MEMS-based infrared thermopile detector array has been developed for multi-gases sensing in the indoor and industrial environments. The designs, fabrications, and characterizations of LVOF and thermopile detector are presented. Experimentally, the LVOF exhibits a mean FWHM of ∼ 400 nm and mean peak transmittance of ∼ 70% at the central wavelength of the operating spectrum of $2.5 \sim 5\ \mu \mathrm{m}$ . The thermopile detectors used ${p-}$ and $n$ -polysilicon/Al metal as thermocouple materials, exhibiting a resistance temperature coefficient of 0.08%/°C and a responsivity of 112 V/W. The LVOF can be regarded as a narrow-band filter array that is installed above the thermopile detector array to form a portable and inexpensive Mid-IR spectrometer for multi-gases sensing.

In this paper, we show that the dynamic performance of multi-mode vertical-cavity surface-emitting lasers (VCSELs) can be modeled by single-mode rate equations developed for edge emitters as long as the lasing modes share a common carrier reservoir. However, this assumption does not hold for ultra-high performing VCSEL devices. Due to the high photon densities inside these optimized VCSELs, the common carrier reservoir splits up as a result of the spatial hole burning effect. This is caused by the high intensity of the multiple transverse modes. In this case, a small-signal modulation response with a different shape is expected. We derive an easy-to-apply fitting function, which allows the extraction of consistently expanded figures of merit. This novel function works for all VCSELs, particularly, including devices with carrier reservoir splitting. Furthermore, we use this new model to perform a detailed analysis of our latest VCSEL generation with a modulation bandwidth of up to 32.7 GHz.

Bereits im Jahr 2020 werden voraussichtlich 20 % aller alteren Krankenhauspatienten an einer Demenz leiden. Dafur sind vor allem drei Faktoren verantwortlich: Die Demografie, die zunehmende Komorbiditat der Demenz mit somatischen Erkrankungen und offensichtlich die Traumen der Narkose, der Intensivmedizin und der chirurgischen Verfahren.

The mouse lung has become increasingly important as a surrogate of the human lung for inhalation risk assessment. The main structural difference between the two lungs is that the airway branching of the human lung is relatively symmetric, while that of the mouse lung is distinctly asymmetric or monopodial. The objectives of this study were to develop a stochastic, asymmetric particle deposition model for the Balb/c mouse and to compare predicted deposition patterns with those in the human lung. The asymmetric bronchial airway geometry of the Balb/c mouse was based on a statistical analysis of several lung casts, while, in the absence of pertinent data, the asymmetric acinar airway geometry was represented by an allometrically scaled-down version of the rat acinar region, assuming structural similarity. Deposition of inhaled particles in nasal, bronchial and acinar airways for mouse-specific breathing conditions was computed with the Monte Carlo deposition model IDEAL-mouse. While total deposition for submicron particles decreases with increasing diameter in a fashion similar to that in the human lung, the effect of inhalability and nasal pre-filtration significantly reduces total deposition in the mouse lung for particles with diameters greater than about 3 μm. The most notable difference between submicron particle deposition in the mouse and human airways is the shift of the deposition distribution from distal airway generations in the human lung to upper airway generations in the mouse lung. However, if plotted as a function of airway diameter, both deposition distributions are quite similar, indicating that airway diameter may be a more appropriate morphometric parameter for extrapolation purposes than airway generation.

We present monolithic 910-nm high power vertical-cavity surface-emitting laser (VCSEL) module suitable for longdistance LIDAR (Light Detection and Ranging). The 910-nm high-power VCSEL array is finely designed and fabricated. The output power of a single VCSEL array (163 devices) reaches nearly 2 W under QCW operation, without being cooled. Driven by the external current source, the peak output power of a single VCSEL array reaches 25.5 W under pulsed operation with a repetition frequency of 10 kHz and a pulse width of 30 ns. To improve the pusled performance of VCSEL array, the monolithic VCSEL array module with integrated driver is developed. The peak output power of this module reaches nearly 85W. And its optical pulse width is 22 ns only. Thus integrated driver circuits demonstrate much better pulsed properties. The ranging setup is built and the detection distance of more than 20 m is realized. We believe that this monolithic VCSEL array with high power, dense package and superior impulse response has great commercial potential in future applications requiring intelligent driving like LIDAR for automotive.

The patterned top-emitting vertical-cavity surface-emitting laser (VCSEL) with a fixed diameter etching window was etched in hydrobromic acid solution with anisotropic etching. An all-semiconductor micro-lens that consisted of alternating aluminum content was directly formed on the output window. The etched curved surface with designed curvature radius makes the mirror loss located at the convex region differ from the edge region. Higher-order modes experience larger mirror loss and are therefore filtered out. The VCSEL with the designed micro-lens reaches a 3.14 mW single-mode power with side-mode suppression ratio >25 dB, which is over 50 times higher than the 0.06 mW single-mode power of the reference VCSEL.

In finite-size high-contrast gratings (HCGs) guided modes with low $Q$ values can occur. On the one hand, this is a resonant mode with a $Q$ value of some hundreds only, on the other hand it can transform part of the finite-size incident wave into the in-plane direction. Such finite-size HCGs with guided modes are proposed here for optical sensors with an on-chip integrated p-i-n photodiode in the same HCG layer. The mode characteristics of the guided mode and the performance of the proposed integrated HCG-based optical sensors are investigated. The proposed integrated HCG-based optical sensors are compact, cost-effective, label-free, and highly sensitive, and can be extended to an array format increasing the throughput.

Vertical-cavity surface-emitting lasers (VCSELs) have emerged as a pioneering solution for many high-speed data communication challenges. Therefore, higher bandwidth optical interconnects with data rates in the range of 100 Gbit/s require directly modulated VCSELs with ultimate speed ratings. The small-signal modulation response of a VCSEL can be isolated from the entire system, thus providing accurate information on the intrinsic laser dynamics. Until now, it is assumed that the dynamic behavior of oxide-confined multi-mode VCSELs can be fully modeled using the single-mode rate equations developed for edge-emitters, even though the deviation between the single-mode based model and the measured data is substantially large. Using an advanced theoretical approach, rate equations for multi-mode VCSELs were developed and the small-signal modulation response of ultra-high speed devices with split carrier reservoirs corresponding with the resonating modes were analyzed. Based on this theoretical work, and including gain compression in the model, the analyzed VCSELs showed modulation bandwidth around and exceeding 30 GHz. The common set of figures of merit is extended consistently to explain dynamic properties caused by the coupling of the different reservoirs. Furthermore, beside damping and relaxation oscillation frequency, the advanced model, with gain compression included, can reveal information on the photon lifetime and highlights high-speed effects such as reduced damping in VCSELs due to a negative gain compression factor.

In this paper, we present a method of self-detection of mode hops in a distributed Bragg reflector tunable laser using the voltage drop in the active section as a monitoring signal. Based on this method, a wavelength setting and stabilization algorithm that is tolerant to temperature variations is proposed. Wavelength locking for a period of more than seven days with an accuracy better than +/- 1.25 GHz has been achieved, meeting the ITU-T standard for 25 GHz channel spacing. Under forced changes in the operation temperature from 15 degrees to 60 degrees, with variations of 0.1 degrees/s, the maximum allowed deviation of +/- 2.5 GHz for the ITU-T standard with 50 GHz channel spacing was kept.

Etwa 10 % aller alteren Menschen in der Wohnbevolkerung nehmen auf Dauer Benzodiazepine ein. Der Anteil steigt auf bis zu 30 % unter den Heimbewohnern oder Krankenhauspatienten. Gerade beim alteren Patienten geht mit der Einnahme ein hohes Risiko fur unerwunschte Arzneimittelwirkungen (UAW) einher. Die hauptsachlichen Gefahren bestehen in der Induktion von Delirien sowie Sturzen mit nachfolgenden huftgelenknahen Frakturen. Die WHO setzt die neueren Z-Substanzen bezuglich ihres Gefahrdungspotenzials den Benzodiazepinen gleich. Es wird empfohlen, unter engmaschiger arztlicher Begleitung Benzodiazepine fraktioniert vollstandig abzusetzen oder zumindest in der Dosis zu reduzieren.

Epidemiological studies proved that cumulative exposure to radon is the second leading cause of lung cancer, the world's most common cancer. The objectives of the present study are (i) to analyse lung cancer risk for chronic, low radon exposures based on the transformation frequency-tissue response (TF-TR) model formulated in terms of alpha particle hits in cell nuclei; (ii) to assess the percentage of attributable lung cancers in six areas of Transylvania where the radon concentration was measured and (iii) to point out the most efficient remediation measures tested on a pilot house in Stei, Romania. Simulations performed with the TF-TR model exhibit a linear dose-effect relationship for chronic, residential radon exposures. The fraction of lung cancer cases attributed to radon ranged from 9 to 28% for the investigated areas. Model predictions may represent a useful tool to complement epidemiological studies on lung cancer risk and to establish reasonable radiation protection regulations for human safety.

The stochastic dosimetry model presented here considers the distinctly asymmetric, stochastic branching pattern reported in morphometric measurements. This monopodial structure suggests that an airway diameter is a more appropriate morphometric parameter to classify bronchial dose distributions for inhaled radon progeny than the commonly assigned airway generation numbers. Bronchial doses were calculated for the typical exposure conditions reported for the Pacific Northwest National Laboratory rat inhalation studies, yielding an average bronchial dose of 7.75 mGy WLM(-1). If plotted as functions of airway generations, the resulting dose distributions are highest in the central bronchial airways, while significantly decreasing towards peripheral generations. However, if plotted as functions of airway diameters, doses are much more uniformly distributed among bronchial airways. The comparison between rat and human lungs indicates that dose conversion coefficients for the rat lung are higher than the corresponding values for the human lung by a factor of 1.34 for the experimental PNNL exposure conditions, and of 1.25 for typical human indoor conditions.

A self-powering ultraviolet photodetector (UVPD) that effectively utilizes UV energy in an easy-to-implement way is an attractive alternative for the UV optical sensing and communication. Here we report a novel self-powered UVPD based on a face-to-face hybrid ZnO nanorod arrays (ZNRAs) nanostructure. Large-area free-standing ZNRAs have been grown on indium tin oxide (ITO) conductive glass and Ti substrates through a hydrothermal method. Different geometric dimension of ZNRAs/ITO and ZNRAs/Ti structures were designed to pair hybrid each other for achieving the optimum photoelectric performance. Experimentally, it is found that the optimum UVPD based on face-to-face hybrid ITO/l-ZNRAs/l-ZNRAs/Ti structure exhibits an enhancement of ‘1+1>2’ in photoelectric conversion without applying any external DC voltage when compared with single-face ZNRAs-based UVPDs, and the optimum UVPD demonstrates a responsivity of 2.45 mA W−1 and on/off current ratio of 6.6 × 105 under a UV irradiation of 3.06 μW cm−2 as well as a high durability with a cyclic balance of no less than 93.5% in a 4250-s on/off irradiation. The generation of self-power and the high photoelectric performance of face-to-face hybrid ZNRAs-based UVPDs are associated to the Schottky junctions in ITO/ZnO interface as well as the extensive ZnO nanorod-nanorod homojunction.

Objective We aimed to assess effectiveness and tolerability of rotigotine in patients with moderate to severe idiopathic restless legs syndrome (RLS) under daily practice conditions in Germany. Methods In this 3-month noninterventional study, effectiveness was assessed using RLS-6 (primary variables were symptom severity when falling asleep [item 2] and during the night [item 3]). Data were collected at baseline and at the end of treatment. Safety assessments included adverse events (AEs). Results Six hundred and eighty-four patients were treated with rotigotine and 418 (61%) completed the study. The full analysis set (FAS) comprised 564 patients (106 de novo; 458 pretreated [454 had complete rotigotine dosing data]). Mean rotigotine dose of longest duration was 2.4 ± 1.4 mg/24 h. Rotigotine improved all RLS-6 items (mean change from baseline [item 2], −2.4 ± 3.6; [item 3], −2.7 ± 3.4), with the most pronounced improvement observed in daytime symptoms while at rest (item 4, −2.9 ± 3.2). AEs were typical of dopaminergic treatment and transdermal administration. De novo patients generally started rotigotine on 1 mg/24 h (85% [90/106]) and pretreated patients on 1 (50% [227/454]) or 2 mg/24 h (40% [183/454]). Most patients who were pretreated with levodopa (57%), pramipexole (84%), or ropinirole (78%) monotherapy discontinued these medications on initiation of rotigotine. Conclusions Rotigotine was effective and well-tolerated when used in routine clinical practice.

The high-frequency electrical properties of a vertical-cavity surface-emitting laser with a monolithically integrated electro-optical modulator are studied using small-signal modulation analysis of the electroreflectance. The experimental data obtained are approximated using the suggested equivalent electrical circuit, which accounts for the formation of a nonequilibrium space charge in the carrier-depletion region of the modulator. The bandwidth of the high-frequency electrical-signal transfer to the electro-optical region, determined for the suggested equivalent electrical circuit of the modulator, is shown to be 3GHz.

With the increasing bandwidth demand of optical interconnects, directly modulated VCSELs with ultimate speed ratings are needed [1]. For serial 100 Gbps solutions, today´s VCSELs have to increase their high-speed performance. Here we report about our next generation devices. The devices discussed here are an optimized version of our very successful high-speed, temperature-stable 980 nm VCSELs [2], and serve as reference-structure for high-contrast-grating high-speed VCSELs, which are in fabrication. Sharing the very short half-lambda cavity and a binary bottom-mirror with 32 pairs, levels are further optimized in order to minimize internal loss. Like previously, parasitics are controlled by two oxide apertures and highly conducting current-spreading layers. InGaAs MQW active layers with strain compensated GaAsP barriers were utilized for high differential gain. The 22 -pair Al12Ga88As/Al90Ga10As top-mirror was replaced by an 18-pair GaAs/Al90Ga10As mirror for lower photon lifetime, better confinement and better heat extraction. The epistructure was grown by IQE Europe. A similar structure with a high-contrast-grating (HCG) mirror is in process. A detailed small-signal analysis is performed. The VCSELs showed modulation bandwidth around and exceeding 30 GHz. The measured data was fitted to single-mode and multi-mode rate-equation based models assuming selforganized carrier reservoirs formed by spatial hole burning. The common set of figures of merit is extended consistently to explain dynamic properties caused by carrier fluctuations. Mode control, which can ideally be performed by high-contrast-gratings, seems essential for next generation highspeed VCSEL devices.

Glaucoma comprises age-related neurodegenerative diseases of retinal ganglion cells, the worldwide prevalence of which is increasing. Local pharmacotherapy is the primary treatment option, especially in the elderly. But this therapeutic approach may include risks for adverse drug effects and drug–drug interactions, of particular importance in frail nursing home resident populations. The aim of the present study was to investigate anti-glaucoma pharmacotherapy in nursing home residents in the context of multi-morbidity and related systemic co-medication. Data for 8,685 nursing home residents with 88,695 drug prescriptions were analysed according to diagnosis and local or systemic pharmacotherapy. Data were provided in anonymous form by a German public health insurance company. The study cohort was characterized by a mean age of 83.6 ± 7.3 years (range: 65–106 years), 21 % of nursing home residents were at least 90 years old and 83.7 % were women. For each nursing home resident, an average of 6.0 ± 3.3 different drugs were registered. A diagnosis of glaucoma was recorded in 520 (6.0 %) nursing home residents; all subjects had co-existing medical conditions. Dementia was a frequent co-morbidity, diagnosed in 51.7 % of nursing home residents with glaucoma. Anti-glaucoma drugs contributed to 0.5 % of all prescriptions and were prescribed to 341 nursing home residents. The most frequently used anti-glaucoma ophthalmics were β-blockers (n = 219), followed by prostaglandin analogues (n = 101) and carbonic anhydrase inhibitors (n = 86). Local anti-glaucoma therapy was co-prescribed with a systemic pharmacotherapy in 338 nursing home residents. An ophthalmic agent was, on average, combined with 6.5 ± 3.2 prescriptions for systemic agents. Thus, 71.9 % of nursing home residents were prescribed ophthalmic β-blockers and a concomitant antihypertensive medication; local and systemic β-blockers were combined in 20.2 % of these patients. Co-treatment with cardiac glycosides or calcium antagonists was found in 13 % of nursing home residents prescribed ophthalmic parasympathomimetics, and in 14 % of those prescribed ophthalmic β-blockers, with the potential for drug–drug interactions to influence cardiac function. Anti-glaucoma pharmacotherapy in nursing home residents is frequently prescribed in the context of polypharmacy. This may modify the efficacy and safety of local and systemic therapies. Therefore, individualized pharmacotherapy that integrates anti-glaucoma drug therapy into the overall treatment rationale in nursing home residents is necessary. However, to realize this concept, further clinical research in nursing home residents is warranted.

Vertical-cavity surface-emitting lasers (VCSELs) are particularly suited for energy- efficient optical interconnects in supercomputing. Consequently, several groups are developing VCSELs for energy-efficient interconnects with remarkable success. We give an overview over recent breakthroughs and present devices at the standard wavelength of 850 nm with record-low power consumption and heat dissipation per bit, achieving a value of only 69 mW/Tb/s at 17 Gb/s. This efficiency is exceeding the International Technology Roadmap for Semiconductors (ITRS) projection of 100 mW/Tb/s for 2015. If uncooled operation, ultradense arrays with smallest footprints, and highest ambient temperatures are required, the waveband around 1 μm is advantageous. At 980 nm, we could achieve an efficiency value in this waveband of 233 mW/Tb/s at an error-free 35 Gb/s.

High-speed oxide-confined 980 nm vertical cavity surface emitting lasers (VCSELs), exhibiting very temperature stable static and dynamic characteristics, are presented, which are well-suited for future optical data link and high-performance computing applications. Error-free operation at data rates of 25 Gbit/s in a wide temperature range from 25 to 85 °C is achieved without the need to adjust any of the electrical driving parameters. Small-signal modulation of VCSELs with different oxide aperture diameters is analyzed to identify the primary mechanisms that control device modulation rate by extracting the standard two-pole rate equation parameters.

The latest advances in 1550-nm high-speed short-cavity vertical-cavity surface-emitting lasers (VCSELs) are presented. The electrical, optical, and thermal design of these devices is discussed with respect to their high-speed modulation behavior. The implemented design improvements allow high output powers for ambient temperatures up to 90°C, high differential quantum efficiencies up to 40%, temperature-stable single-mode emission, low thermal resistances down to 1.6 K/mW, small-signal modulation bandwidths in excess of 17 GHz, and error-free data transmission at room temperature at data rates of 35 Gb/s in back-to-back configuration and up to 25 Gb/s over 4.2 km of single-mode fiber.

Two different modelling approaches are currently used to calculate short-lived radon progeny doses to the lungs: the semi-empirical compartment model proposed by the International Commission on Radiological Protection and deterministic and stochastic airway generation models. The stochastic generation model IDEAL-DOSE simulates lung morphometry, transport, deposition and clearance of inhaled radionuclides, and cellular dosimetry by Monte Carlo methods. Specific dosimetric issues addressed in this paper are: (1) distributions of bronchial doses among and within bronchial airway generations; (2) relative contributions of radon progeny directly deposited in a given airway generation and those passing through from downstream generations to the bronchial dose in that generation; (3) distribution of bronchial doses among the five lobes of the human lung; (4) inhomogeneity of surface activities and resulting doses within bronchial airway bifurcations; (5) comparison of bronchial doses between non-smokers and smokers; (6) relative contributions of sensitive target cells in bronchial epithelium to lung cancer induction and (7) intra- and intersubject variations of bronchial doses.

To explore the role of the multiplicity of cellular hits by radon progeny alpha particles for lung cancer incidence, the number of single and multiple alpha particle hits were computed for basal and secretory cells in the bronchial epithelium of human airway bifurcations. Hot spots of alpha particle hits were observed at the branching points of bronchial airway bifurcations. The effect of single and multiple alpha particle intersections of bronchial cells during a given exposure period, selected from a Poisson distribution, on lung cancer risk were simulated by a transformation frequency--tissue response model, based on experimentally observed cellular transformation and survival functions. Calculations of lung cancer risk at low radon exposure levels suggest that single hits produce a linear-dose response relationship, while the superposition of single and increasing multiple hits at higher exposure levels may also be approximated by a quasi-linear dose-effect curve. The simulations predict a carcinogenic enhancement effect for radon progeny accumulations at bifurcation branching sites, which may increase current risk estimates.