This PDF file contains the front matter associated with SPIE Proceedings Volume 8065, including the Title Page, Copyright information, Table of Contents, Introductions, and the Conference Committee listing.

Safety considerations have always driven the way for improving exterior automotive lighting legal requirements. With the recent adoption of day-time running lamps for passenger cars, the steadily increasing need for reduction of vehicle power consumption has led to the introduction of LED-based day-time running lamps. Solutions with incandescent bulbs have also been implemented, as they present price advantages while offering limited design perspectives. In the meantime, technology developments has turned LED sources into ideal candidates for daytime running lamps by increasing their lumen per watt efficiency ratio towards values around 100 lm/W or higher. In this work, taking as an example the new Mercedes-Benz roadster SLK (R172), we present the first single LED daytime- running lamp, with a total power consumption below 5W per vehicle. After reviewing legal requirements, the optical and electronic concepts are discussed. Details on the tail lamp LED functions are also discussed, and particularly the advantages from the realization of fog lamp with LEDs.

The complexity of sustainable energy systems for buildings services calls for more transparency of the processes which provide energy for the buildings heating, cooling and power needs. In the frame of applied scientific research at University of Applied Sciences Offenburg, different systems and even buildings in total have been monitored over years to analyse their performance and to optimize the system installations and operations. New EU regulations like EN 16001 require an effective monitoring and a continuous commissioning of the energy relevant systems to certificate sustainable processes. On the other hand, new operation tools are necessary to handle the volatility of renewable energy sources and the buildings demand. Predictive building automation has shown good results when applied for energy systems with high inertia. Operating large-scale solar thermal systems and sustainable buildings over long-term periods the University of Applied Sciences provided evidence that monitoring is an essential system tool for an energy and cost efficient operation of sustainable buildings.

We propose a Linear Irregular Fresnel Lens (denoted as LIFL) to replace the diffusion sheet and prism sheet in a rectangular LED-based Direct-type Backlight Module. The aim is to improve the illuminance and uniformity of LCD panel, as well as to reduce the cost of Backlight Module and make the Module thin. Here "Linear" means the grooves of a Fresnel lens are arranged linearly and "irregular" means that the sequence of all groove angles is not increasing or decreasing. To let the designed LIFL possess good effects of light ray guiding, two layers of LIFLs are needed. The first layer LIFL consists of x-axis grooves, whereas the second layer LIFL consists of y-axis grooves to guide all light rays guided by the first layer LIFL. The groove angles of the designed LIFL are evolved by a Genetic Algorithm which is developed in terms of the performance requirement on illuminance and uniformity of LCD panel in a rectangular LED-based Direct-type Backlight Module. In this paper, we will simulate a simple fifteen-LED Direct-type Backlight Module to demonstrate the performances on illuminance and uniformity of the designed LIFL.

To optimize the quantum efficiency (QE) and short-circuit current density (J_SC) of silicon thin-film solar cells, one has to study the behavior of sunlight in these solar cells. Simulations are an adequate and economic method to analyze the optical properties of light caused by absorption and reflection. To this end a simulation tool is developed to take several demands into account. These include the analysis of perpendicular and oblique incident waves under E-, H- and circularly polarized light. Furthermore, the topology of the nanotextured interfaces influences the efficiency and therefore also the short-circuit current density. It is well known that a rough transparent conductive oxide (TCO) layer increases the efficiency of solar cells. Therefore, it is indispensable that various roughness profiles at the interfaces of the solar cell layers can be modeled in such a way that atomic force microscope (AFM) scan data can be integrated. Numerical calculations of Maxwell's equations based on the finite integration technique (FIT) and Finite Difference Time Domain (FDTD) method are necessary to incorporate all these requirements. The simulations are performed in parallel on high performance computers (HPC) to meet the large computational requirements.

To verify optimization measures of power generators to improve the energy efficiency and to monitor critical parameters, fiber optical sensors have been developed and investigated. A fiber optical hot wire anemometer based on the thermooptic effect of Fiber Bragg Gratings was investigated to measure the flow distribution along the stator core. Fiber optical magnetic field sensors, based on the strain-optic effect of FBGs, were used to measure the magnetic field distribution on the end windings of a power generator. A novel fiber-optical accelerometer was used to measure the end winding vibrations. In this paper the functionality of each sensor is described and results of field test under real conditions are shown and discussed.

The photoelectrical responsibility of single photo-electronic devices makes it difficult to achieve high efficiency of photoelectric conversion in the full solar spectrum range. The key to overcome the physical limits is to develop the system consisting of a set of solar cells in which the photo-electronic conversion of each cell will match to the sub-spectrum of the solar radiation with high conversion efficiency. In this work, we have used the spectrum splitting method to divide the solar spectrum into four sub-ranges of 400-630nm, 630-800nm, 800-900nm and 900-1800nm, respectively. Four high performance single-junction photo diodes are used, and each of them has high quantum-efficiency of photo-electronic conversion matching to the sub-ranges of solar spectrum. Under the 0.5-6.0 SUN radiation condition, the photo-electrical conversion efficiency of the system with four solar cells has been measured with the result to show that the photo-electric conversion efficiency of 35% is achieved under the typical 2.8 SUN radiation condition. The results given in this work will provide a way to show the potencial to realize a high photo-electric conversion efficiency (>40%) of the solar system in application.

Nanoscale Si-layered systems represent an attractive way to enlarge optical and electrical functions in Si optoelectronic, photonic and PV technology. Physical interactions transform the initial Si material to a new Si-based metamaterial. The device architecture also plays a role in specific nonlinear features. The newly observed behavior requires a better insight into understanding the mechanisms determining the macroscopic performance. We report here some specific electrical properties resulting from the complexity of the electron transport in different test structures designed and manufactured by us. One of the most important parameters concerns state of the device surface. Measurements have been carried out in different conditions of illumination (spectral composition, intensity, with/without optical bias), acquisition mode (duration of acquisition) and device polarization mode (photodiode, photovoltaic). Time-resolved current collection with stabilized voltages, as well as time-resolved voltage variation under stabilized currents, both made under light excitation, allowed observation of extremely long time constants.

Radial and Linear Fresnel Lenses are finding application as light concentrators for Concentrated Photovoltaic and Concentrated Solar Thermal power applications. The efficiency of these diffractive lenses directly affects the yield of such systems. Peaks and valleys of the optical facets of the Fresnel lens must be sharp in order to prevent diffusion and transmission loss due to rounding. For diamond turned mould masters, optical facet tip sharpness is affected by machining accuracy, tool-path and tool wear/mileage. Strategies to optimise optical facet tip sharpness are presented which enable production of large lenses with minimal degradation of optical quality. Radial Fresnel produced with diameters over 500mm and Linear Fresnel over 1m long are discussed with data on structure fidelity and tool wear.

Finding the optimal structure to enhance light trapping in thin film silicon solar cells has attracted much attention in the previous decades. However, because of problems in integrating theory and experiment, there are only few comprehensive contributions that provide guidelines for the optimal design of such structures. In this work, a realistic thin film solar cell with almost conformal layers based on a one-dimensional metallic grating back-reflector is investigated through experiment and theory. The external quantum efficiency of the cell is obtained with the aid of both theory and experiment for different angles of incidence and in both polarizations to validate the computational method and to show the impact of guided mode excitation. Different substrate shapes that are compatible with solar cell fabrication are then considered and the effect of geometrical parameters on the short circuit current density of the device is investigated. Calculations show that among the investigated shapes, trinagular gratings with a very sharp slope in one side, so called sawtooth gratings, are the most promising one-dimensional grating for light trapping. Furthermore, the role of material property is discussed specifically in the back-reflector by simulating aluminum and silver backreflectors. It is shown that the blue response of the solar cells is similar almost regardless of the back-reflector material but their red response is viable to change due to variation in resonant properties of the structure.

As a reason of their electrical conductivity and transparency in the visible spectral range transparent conductive oxides (TCOs) are well known as electrodes for OLEDs or LCD displays. Another promising application is a semiconductor-insulator-semiconductor (SIS) solar cell, in which the TCO induces the pn junction and realises a low cost solar cell on crystalline silicon. By using nanostructured silicon interfaces broadband antireflection properties with effective light coupling into the silicon can be achieved. Combined with the SIS concept it is possible to fabricate a low cost and high efficient PV device. For the deposition of thin films of indium tin oxide (ITO) and aluminum doped zinc oxide (AZO) pulsed dc magnetron sputtering is used. The paper presents the surface modification of silicon by inductive coupled plasma (ICP) etching technology, discusses the influence of different TCO materials to the device, and analyses the optical and structural properties of the cells. Furthermore, the solar cell performance under AM1.5G illumination will be shown.

Due to their metabolic flexibility and fast growth rate, microscopic aquatic phototrophs like algae have a potential to become industrial photochemical converters. Algae photosynthesis could enable the large scale production of clean and renewable liquid fuels and chemicals with major environmental, economic and societal benefits. Capital and operational costs are the main issues to address through optical, process and biochemical engineering improvements. In this perspective, a variety of photonic approaches have been proposed - we introduce them here and describe their potential, limitations and compatibility with separate biotechnology and engineering progresses. We show that only sunlight-based approaches are economically realistic. One of photonics' main goals in the algae field is to dilute light to overcome photosaturation effects that impact upon cultures exposed to full sunlight. Among other approaches, we introduce a widely-compatible broadband spectral adaptation technique called AlgoSun® that uses luminescence to optimize sunlight spectrum in view of the bioconverter's requirements.

One of the most challenging topics of today's research and development concerns efficiency of light-to-electricity conversion, preferably on Si-derived devices. The best of the possible/imaginable solutions has to allow overcoming the indirect Si bandgap constraints. This aim becomes realizable by transforming the hard photon-matter interaction into a soft photon-electron-electron interaction with additional new low-energy mechanisms to allow a multistage conversion cycle. Such effects have been observed by us within new Si-derived metamaterials obtained by multiple transformations, leading to a nanoscale Si-layered system. In such systems, a giant photoconversion could be observed for the first time due to hot electron interactions with active interfaces and conditioned crystalline defects transformed into Si metamaterial units, called tectons. Today it seems to be the best way to overcome conversion shortages of the bulk, thinfilm or any other Si-based devices. We present in this work a background and three experimental demonstrations of giant photoconversion.

Up to now CO₂ is considered as a waste which should be extracted from the atmosphere and stored in the ground (CCS). The European Parliament has already decided to initiate such a technique. In this paper we show that CARBON DIOXIDE can be considered as a RAW MATERIAL which can be processed into a chemical fuel, for example into methane or synfuel. This is a drastic change to the present views. The process is based on two steps: - reduction of water to generate hydrogen - reduction of carbon dioxide with the generated hydrogen in presence of adequate catalysts. This technique will allow a storage of electricity at large scale in a chemical fuel, which will become a necessity when the electric grid will integrate large amount of renewable energy sources (PV or wind).

Optical direct detection usually operates far above the quantum limit, due to the high thermal noise level of PIN photodiodes. For signal energy at the quantum level, the thermal effects in photon counters are also a strong limitation. The optical amplification or the heterodyne detection of the 2 quadratures of the field, widely used in high bit rate and long haul optical systems, overcome this limitation at the expense of a minimum 3db noise figure. By allowing a noise free mixing gain, as well as single quadrature measurements, the balanced homodyne receiver is allowed to reach quantum noise limited operation. The aim of this paper is to review the different quantum receiver implementations and to compare the minimum signal energy required to achieve a given bit error rate, or a given bit erasure rate, in high bit rate communications and quantum communications. Application to quantum cryptography will be also addressed.

Hybrid CSP / CPV (Concentrating Solar Power / Concentration Photovoltaic) systems provide a good alternative to traditional CPV systems or CSP trough architectures. Such systems are often described as solar cogeneration systems. Trough systems use mainly the IR portion of the spectrum in order to heat up a pipe in which water is circulating. CPV systems use only the visible portion of the spectrum to produce the photo-voltaic conversion. Due to the achromatic nature of traditional thermal trough CSP systems, it is very unlikely that a CPV system can be integrated with a CSP system, even a low concentration CPV system (LCPV). We propose a novel technique to implement a low concentration CSP/LCPV system which relies on commercially available solar trough concentrators / trackers that use reflective stretched Mylar membranes. However, here the Mylar is embossed with microstructures that act only on the visible portion of the spectrum, leaving the infrared part of the solar spectrum unperturbed. This architecture has many advantages, such as: the existing Mylar-based thermal trough architecture is left unperturbed for optimal thermal conversion, with linear strips of PV cells located a few inches away from the central water pipe; the infrared radiation is focused on the central pipe, away from the PV cells, which remain relatively cool compared to conventional LCPV designs (only visible light (the PV convertible part of the solar spectrum) is diffracted onto the PV cell strips); and the Mylar sheets can be embossed by conventional roll-to-roll processes, with a one-dimensional symmetric micro-structured pattern. We show how the positive master elements are designed and fabricated over a small area (using traditional IC wafer fabrication techniques), and how the Mylar sheets are embossed by a recombined negative nickel shim. We also show that such a system can efficiently filter the visible spectrum and divert it onto the linear strips of PV cells, while leaving the infrared part of the spectrum un-perturbed, heating up the water pipe.

In this study, we report a simple, precise, and nano-scale fabrication technique for oxide nanosphere structure rutile (TiO₂) using couple hundred of femtosecond laser irradiation at MHz pulse repetition frequency in air at atmospheric pressure. Measured reflectance's through Spectroradiometer show that their couplings of incident electromagnetic irradiations are improved greatly over the broad band wavelength range. Lower reflectance intensity obtained with long dwell time is due to generate bulk quantity of TiO₂ oxide nanoparticle agglomerate by fusion, and form interweaving fibrous structures that show certain degree of assembly. The X-ray diffraction test confirmed that the oxide titanium metallic nanostructure is a rutile phase (TiO₂). The growth of TiO₂ nanostructure is highly recommended for the applications of dye-sensitized solar cells and photovoltaic applications.

Analytic representation of optical function is necessary for the device and structural modeling. Nowadays optoelectronic devices consist of complex materials combined together, therefore accurate representation of each part is even more important and results in prediction of overall structure properties. The complete model for amorphous and crystalline Si:P dielectric function is presented. Range of accuracy, known problems and model parameters are studied and described. New interesting features of Si:P dielectric functions are discussed. The influence of dopants and free-carriers is taken into account and studied separately and their overlap is also analyzed. The influence of Drude damping time on the optical response of heavily doped Si:P is studied. All results are then compared with experimental data.

Today many challenges lie ahead of the aircraft industry. The increasing competition and shortage of resources raise a challenge for future manufacturing technologies and lightweight design. A possibility to cope with these circumstances is the manufacturing technology of Laser Additive Manufacturing (LAM). However there are still challenges to cope with due to the processes novelty, such as the development of further materials, especially lightweight alloys, and new design approaches. Therefore innovative approaches for material development and lightweight design were created in order to fully exploit the processes potentials. The material development process is based on an analytical calculation of temperature distribution versus effective process factors in order to identify acceptable operating conditions for the LAM process. A novel approach to extreme lightweight design was realized by incorporating structural optimization tools and bionic structures into one design process. By consequently following these design principles, designers can achieve lightweight savings in designing new aircraft structure and push lightweight design to new limits.

The National Optical Astronomy Observatory, Science Foundation Arizona, and the University of Arizona are teamed on a long-term multi-pronged approach to photonics education in Arizona that is congruent with a "green" future. This approach involves education around the content areas of renewable energy sources, laser-based communication and laser-assisted manufacturing, photovoltaics, solid-state lighting and displays, nanotechnology, and other recent technology developments. Equally important is the process by which we are working to transform the Arizona K-12 schools and universities through programs that emphasize problem-solving, system thinking, and collaborative approaches. We also emphasize the role of the informal education system (such as museums) and the value of "freechoice" learning to science education. A key to our success is the work of traditionally research-oriented organizations and industry associations in supporting science and technology education.

Engineering and science technicians are urgently needed in photonics (lasers and electrooptics). Twenty-eight post secondary institutions offer education for technicians in this field; however their enrollments are low because there are not sufficient efforts to attract high school students through interesting, relevant activities in science and technology classes. This paper describes three activities, using light-emitting diodes, which have been developed by faculty in the Electro-Optics Program at Indiana University of Pennsylvania. These "green energy" related topics are provided in "hands-on" activities for nearby high school students and teachers. They have successfully generated interest by the students to enroll in photonics after high school graduation.

Nowadays, mobile devices are more and more powerful concerning processing power, main memory and storage as well as graphical output capability and the support for 3D mostly via OpenGL ES. Therefore modern devices allows it to enable Virtual Reality (VR) on them. Most students own (or will own in future) one of these more powerful mobile device. The students owning such a mobile device already using it to communicate (SMS, twitter, etc) and/or to listen to podcasts. Taking this knowledge into account, it makes sense to improve the students learning experience by enabling mobile devices to display VR content.

About one-third of outdoor lighting escapes unused into the sky, wasting energy and causing sky glow. Because of excessive sky glow around astronomical facilities, the National Optical Astronomy Observatory has a strong motivation to lead light pollution education efforts. While our original motivation of preserving the dark skies near observatories is still important, energy conservation is a critical problem that needs to be addressed nationwide. To address this problem we have created an extensive educational program on understanding and measuring light pollution. A set of four learning experiences introduces school students at all grade levels to basic energy-responsive illumination engineering design principles that can minimize light pollution. We created and utilize the GLOBE at Night citizen science light pollution assessment campaign as a cornerstone activity. We also utilize educational activities on light shielding that are introduced through a teaching kit. These two components provide vocabulary, concepts, and visual illustrations of the causes of light pollution. The third, more advanced component is the school outdoor lighting audit, which has students perform an audit and produce a revised master plan for compliant lighting. These learning experiences provide an integrated learning unit that is highly adaptable for U.S. and international education efforts in this area.

This paper shows the analysis of the poster announcing the SPIE Conference. As the research object, the poster was tested in a pretest by few testpersons in the eyetracking lab. On the base of this pretest the final eyetracking research will follow soon. Beside the description of the results of the pretest, the paper explains the eyetracking method and the applications of eyetracking in education of optics and photonics.

There is considerable evidence from the physics education literature that traditional approaches are ineffective in teaching physics concepts. A better teaching method is to use the active learning environment, which can be created using interactive lecture demonstrations. Based on the active learning methodology and within the framework of the UNESCO mandate in physics education and introductory physics, the ALOP project (active learning in optics and photonics) was started in 2003, to provide a focus on an experimental area that is adaptable and relevant to research and educational conditions in many developing countries. This project is discussed in this paper.

As widely known laser materials processing has some advantages regarding local heat input and controllability. In many fields applications were developed which are not accessible for conventional thermal processing. In other fields laser-supported manufacturing techniques are a valuable alternative. On the one hand laser techniques enable increased processing speed and less post-processing, leading to an increased productivity. On the other hand low efficiencies in the energy conversion seem to be a major drawback and apparently limit the range of applications. In the frame of conventional processing schemes laser beam welding requires a high utilization in order to run economically. Main advantages lie in the reduced consumption of material and the reduced efforts in post processing. Because of the locally concentrated heat input process emissions are lower which reduces energy and material consumption in the auxiliary chain. To make full use of the often-conjured flexibility a multitude of manufacturing schemes had been developed and adapted. In order to appraise the versatility of laser driven processing techniques a cost and benefit analysis based on a life-cycle approach is conducted including both, economics and ecology. Eco-efficiency is rated by a variation of the BASF method. Taking into account the reduced consumption of consumables, reduced effort for preparation and post-processing, and focusing on specific application ranges a positive environmental impact can be proven.

The use of laser light for bonding of continuous fiber reinforced thermoplastic composites (CFTPC) offers new possibilities to overcome the constraints of conventional joining technologies. Laser bonding is environmentally friendly as no chemical additive or glue is necessary. Accuracy and flexibility of the laser process as well as the quality of the weld seams provide benefits which are already used in many industrial applications. Laser transmission welding has already been introduced in manufacturing of short fiber thermoplastic composites. The laser replaces hot air in tapelaying systems for pre-preg carbon fiber placement. The paper provides an overview concerning the technical basics of the joining process and outline some material inherent characteristics to be considered when using continuous glass fiber reinforced composites The technical feasibility and the mechanical characterization of laser bonded CFTPC are demonstrated. The influence of the different layer configurations on the laser interaction with the material is investigated and the dependency on the mechanical strength of the weld seem is analyzed. The results show that the laser provides an alternative joining technique and offers new perspectives to assemble structural components emerging in automotive or aeronautical manufacturing. It overcomes the environmental and technical difficulties related to existing gluing processes.

Profiting by the increasing availability of laser sources delivering intensities above 10⁹ W/cm² with pulse energies in the range of several Joules and pulse widths in the range of nanoseconds, laser shock processing (LSP) is being consolidating as an effective technology for the improvement of surface mechanical and corrosion resistance properties of metals and is being developed as a practical process amenable to production engineering. The main acknowledged advantage of the laser shock processing technique consists on its capability of inducing a relatively deep compression residual stresses field into metallic alloy pieces allowing an improved mechanical behaviour, explicitly, the life improvement of the treated specimens against wear, crack growth and stress corrosion cracking. Following a short description of the theoretical/computational and experimental methods developed by the authors for the predictive assessment and experimental implementation of LSP treatments, experimental results on the residual stress profiles and associated surface properties modification successfully reached in typical materials (specifically Al and Ti alloys) under different LSP irradiation conditions are presented. In particular, the analysis of the residual stress profiles obtained under different irradiation parameters and the evaluation of the corresponding induced surface properties as roughness and wear resistance are presented.

In different study fields the manipulation and imaging of micro-sized particles is essential. The use of holographic optical tweezers (HOT) and digital holographic microscopy (DHM) facilitates this task in a non-mechanical way by providing the proper computer generated hologram and the required amount of light. Electrically addressed spatial light modulators (EASLM) found in holographic optical tweezers are typically of the reflective liquid crystal on silicon (LCoS) type which can achieve a phase shift of more than 2π but they are expensive. Similar components like transmissive twisted nematic liquid crystal displays (TN-LCD) are produced in large quantities, their optical characteristics improve rapidly and they are inexpensive. Under certain circumstances these devices can be used instead of expensive spatial light modulators. Consumer grade objectives are not always well corrected for spherical aberration. In that case conventional liquid crystal displays can also compensate these undesired optical effects. For this purpose software-corrected computer generated holograms are calculated. Procedures to analyze and compensate different parameters of a conventional low-cost liquid crystal display, e.g. phase shift evaluation and aberration correction of objectives by Zernike polynomials approximation are explained. The applied software compensation of the computer generated hologram has shown significant improvement of the focus quality. An important price reduction of holographic devices could be achieved by replacing special optical elements if correction algorithms for conventional liquid crystal displays are provided.

Even today laser spot welding of copper is a challenging application in the micro-electronic industry. Requirements for yield, strength and process stability are high and still increasing. Typical applications are bonding and contacting. In general laser welding is considered as a process with high reliability. But copper alloys especially have characteristic properties like high heat conduction, inconstant absorption level depending on surface conditions and material temperature, abruptly changing physical state between solid and liquid condition etc. There are existing strategies like pulse forming and beam shaping as well as adaptation of the laser wavelength which can be used to increase the process reliability of the spot welding of highly reflective materials. Moreover a closed loop control was developed which is able to set up the process parameters even inside of the working pulse based on the process signals feedback. The paper contains a survey of the existing methods of increasing the process reliability and will show advantages and disadvantages of the single strategies. The initial results of using closed loop feedback control systems for copper welding under industrial conditions will be presented, as well as a novel method where IR and green wavelength mixing is used to achieve reproducible and energy-efficient copper welds.

Rising energy costs make energy efficiency a key topic of the future for different industrial production processes. Thermal joining is widely used in the production process and causes a lot of energy lost. Both weld seam and filler material have to be heated to temperatures higher than the melting point. During the process a high amount of heat conducts into the work piece. Process efficiency and decrease of the energy consumption can be achieved through decreasing of the process temperature and the weld metal volume, respectively. To achieve these goals, material and process developments have to be carried out. These can result energy savings up to 40% are established in laser and arc welding processes. Nanotechnology is an innovative means to reduce required energy for joining processes. High energy which is necessary in the joining area can be generated in milliseconds only by using nanostructured reactive foils. Furthermore, the process velocity can reach several m/s. Due to the size effect the melting temperature of nanoparticles decreases inversely proportional to the radius. Therefore Ag nanoparticles with a diameter of 10 nm melt at about 200°C which has to be compared to micro, meso or macro sized Ag particles melting at 960°C. Filler material manufacture based on this effect allows producing metallurgical joints at very low temperatures. After the joining process the size effect disappears. This means that the reflow temperature is equal to the macroscopic melting temperature. Material and process developments offer a wide variety of opportunities to reduce the energy consumption in thermal joining processes. Especially taking advantage of nano effects to decrease the process temperature and increase the process velocity has great potential for future applications.

A robust, flexible Fourier transform Raman spectrometer (FT-Raman) based on a Michelson interferometer and a self-made photon counter is presented. The proposed inexpensive setup has no complex hardware or control systems for optical path compensation. The mechanical and thermal induced errors are mathematically compensated by extracting the optical path information from the generated interference pattern of a λ = 632.8nm Helium-Neon laser (HeNe laser). This information also permits high frequency precision of the calculated Raman spectrum. This system is flexible and allows the user having complete access to hardware and software. It enables a variety of experimental changes in the system, which are difficult to achieve with commercial devices. Precise, high resolution Raman spectra of cyclohexane with a resolution of 1.66 cm^-1 to 5.0cm^-1 have been measured with this device. Higher resolution values can be achieved since longer scanning distances at the Michelson interferometer are possible and its calculated ´etendue (throughput) does not substantially corrupt the obtained interferograms. Other chemical compounds have been also monitored. Additionally, a detailed spectral analysis of different precision optical components and light sources has been performed.

Optical glass is part of optical systems, being subject to the EU directive RoHS, restricting the use of certain hazardous substances in electric and electronic equipment. Some special optical and filter glasses contain lead or cadmium, since these elements are essential for some special glass properties needed by high end optical systems. Most lead containing glass for consumer optics has been replaced by lead free versions. A lot of effort has been spent searching for substitute glass types. But for some remaining applications a set of lead or cadmium containing glass types have revealed to be irreplaceable. Even though they are used only in small amounts and are of negligible environmental influence, long and tedious effort was necessary to obtain an exemption from the directive. The optics community has to stay alert to prevent vast damages due to possible non-availability of glass types crucial for very important applications such as fluorescence microscopy. There are tendencies to restrict the use of even more elements, which could endanger the existence of most optical and filter glass types. These materials are key enabling factors of technical civilization as a whole because they are used in all industries and many research fields. They must be taken out of the scope of RoHS in total since exemption procedures will lead to periods of secured availability too short to be acceptable for the design of optical systems, which usually takes years and in high end optics must be valid also for long term deliveries. New regulations improving ecological aspects should assess the consequences on other important goals of society.

This paper presents a communication as well as localization algorithm of a multi laser tracker system (MLTS). The proposed localization algorithm enables the possibility to find a retro-reflector, which is mounted on the Tool Center Point (TCP) of a positioning stage. The MLTS consists of four laser trackers and is used as a high precision feedback sensor in order to provide a contactless measurement of the position. A single laser tracker is build up out of a homodyne laser interferometer as well as a galvanometer scanner and tracks the retro-reflector by utilization of a model-based PID controller. Using the Archimedean spiral a mathematical localization algorithm of the retro-reflector is designed. This approach was chosen due to the fact, that it allows the laser beam to search the retro-reflector in the complete working range of the tracker. The algorithm is derived in polar coordinates and is afterwards transformed into angle coordinates of the galvanometer scanner. In the second part of the presented study, a communication channel between the laser trackers is designed. This enables the possibility to speed up the localization of the retro-reflector significantly, because the position of the TCP is determined using the triangulation. Hence only two laser trackers are required in the first localization step. In the case, that the TCP was found, the information is utilized to support the residual laser trackers of the MLTS to localize the retro-reflector. At the end it is shown by experimental results, that the communication between the laser trackers is effective in order to localize the retro-reflector as fast as possible.

The microscopic three-dimensional imaging of cells is a key method in biological and medical research. Conventional high-resolution scanning methods e.g. laser scanning microscopes are limited or require some form of compensation in monitoring of living cells. The proposed method uses a low-cost twisted nematic liquid crystal display (TN-LCD) which is used as phase modulating electrically addressed spatial light modulator (EASLM) to holographically generate a reference wave which can be translated and shift in phase. Wavefront distortions caused by aberrations are determined by scanning the system with the EASLM, approximating them with Zernike polynomials and calculating a phase correction function which can be superposed with the hologram. The interference pattern of the object and shifted reference wave is captured with a CMOS camera and subsequently the object wave is reconstructed from the taken images. With this procedure it was already possible to reconstruct a diatom in different layers.

When a city or a local authority wishes to emphasize its historical heritage, for the lighting of its streets, setting up lights during the festive season, they call upon the skills of a lighting designer. The lighting designer proposes concepts, ideas, lighting, and to be able to present them, he makes use of simulation. On the other hand lighting technologies are evolving very rapidly and new lighting systems offer features that lighting designers are now integrating their projects. The street lights consume lot of energy; light projects are now taking into account the energy saving aspect. Lighting systems based on LEDs today provide good lighting needs, taking into account sustainable development issues while enabling new creative dimension. The lighting simulation can handle these parameters. Images or video simulation are no longer sufficient: stereoscopy and virtual reality techniques allow better communication and better understanding of projects. Virtual reality offers new possibilities of interaction, the freedom of movement in a scene, the presentation of variants or interactive simulations.

Photonic technologies will play an increasingly significant role in reducing our environmental impact. In addition to the direct eco-benefits derived from the products themselves, green photonics will also impact the product design and manufacturing processes employed. Examples are discussed covering laser manufacturing, solid-state lighting, solar cells and optical communications. The importance of considering the full lifetime environmental impact of products is discussed, including raw materials, manufacture, use, and end of life issues. Industrial and legislative strategies are reviewed, and a number of specific measures are presented for accelerating the development of green photonics technologies and promoting their adoption into society.

The energy consumption of telecommunication networks has gained increasing interest throughout the recent past: Besides its environmental implications it has been identified to be a major contributor to operational expenditures of network operators. Targeting at sustainable telecommunication networks, thus, it is important to find appropriate strategies for improving their energy efficiency before the background of rapidly increasing traffic volumes. Besides the obvious benefits of increasing energy efficiency of network elements by leveraging technology progress, load-adaptive network operation is a very promising option, i.e. using network resources only to an extent and for the time they are actually needed. In contrast, current network operation takes almost no advantage of the strongly time-variant behaviour of the network traffic load. Mechanisms for energy-aware load-adaptive network operation can be subdivided in techniques based on local autonomous or per-link decisions and in techniques relying on coordinated decisions incorporating information from several links. For the transformation from current network structures and operation paradigms towards energy-efficient and sustainable networks it will be essential to use energy-optimized network elements as well as including the overall energy consumption in network design and planning phases together with the energy-aware load-adaptive operation. In load-adaptive operation it will be important to establish the optimum balance between local and overarching power management concepts in telecommunication networks.

At the Hochschule Offenburg, a fully controlled helicopter has been developed, which is very easy to fly by anybody and can be flown very close to objects. The flight control system consists of an attitude and heading reference system, an inertial navigator augmented by GPS and a flight control computer. The electrically driven helicopter can easily carry payloads of more than 1 kg. With this helicopter high resolution pictures were taken from parts of the Freiburg cathedral. Also pictures with a calibrated camera of terrain have been taken. Pictures were paired and using a commercial software, a 3D-model of a part of the top of the "Hahnenturm" of the Freiburg cathedral has been generated. The terrain pictures have been bundled and used to precisely measure the position of certain objects in the terrain. The first results of these trials are very promising in respect to future applications of the helicopter.

Modern mobile communication devices have user interfaces that are dominated by high-quality displays. Increased multimedia use imposes high demands on the design of display modules, as the content available for mobile use becomes visually richer. Especially the power dissipation of the display can limit the amount of time available for multimedia consumption and interaction. In the mobile liquid-crystal display (LCD), the energy efficiency is determined by the backlight design. State-of-the-art backlights direct white light through a display subpixel array, with high uniformity and up to 90 % efficiency in white light output. Diffractive backlights have recently been proposed to reduce the power dissipation of the display module, and slanted grating arrays are among the enabling optical features that allow for reduction in power dissipation beyond what is available in the state of the art. By the use of diffractive grating arrays, the required primary color (red, green, or blue) is directed through the LCD subpixel array with geometrical registration, instead of flooding the whole LCD with white light and filtering the primary colors through the subpixel color filter array. This paper presents a study on grating structures based on slanted grating arrays fabricated in high refractive index materials. The grating design and grating outcoupling results are provided, and an outline of a new embedded system design is given. Emphasis is on grating array design aspects for future display system design. The results show that savings in power consumption can be expected with advanced display system design based on embedded slanted grating array backlight light guide plates.

Combination of quadrature amplitude modulation with coherent detection is attractive for optical transmission systems, since it permits an increase of data rate without increasing the symbol rate or the required bandwidth. 16-point Quadrature Amplitude Modulation (16-QAM) is most interesting in this context. In-phase (I) and quadrature (Q) signals transmit 2 bit each. Together with polarization division multiplex this amounts to 8 bit/symbol. 2.5 Gbit/s synchronous coherent 16-QAM data is transmitted and received in a realtime intradyne setup with BER below FEC (7% overhead) threshold. A phase noise tolerant feedforward carrier recovery concept with hardware-efficient implementation was tested. Transmission was error-free in a back-to-back electrical test for various PRBS lengths. The carrier recovery does not contain any feedback loop and is therefore highly tolerant against laser phase noise.

Photonic routers are expected to enable ultra-high bit rates, high levels of integration and power efficiency. The BOOM European project aims to develop on a SOI platform the photonic bricks towards the first silicon-optics switch fabric.

Electrowetting displays were first reported in 1981, several approaches were examined. However, ADT's "Droplet- Driven-Displays" technology is the only bistable one which makes them very attractive for energy-saving systems. That means that the power supply can completely shut off after changing the content and it will keep its information for years. More features that make the ADT approach very unique are paper like white appearance (even in the powerless OFFstate) and the capability for backlighting (most of the other e-paper technologies like electrophoretics can not be backlighted). Further achievements are a white state reflectance of about 70% resulting in sunlight readability and a pixel size in the range from 0.3mm to 10mm. Summarizing, ADT's electrowetting technology is highly suitable for lowest power (means eco-friendly or "green") displays.

A design to optimize a fiber optic Surface Plasmon Resonance (SPR) sensor using Palladium as a sensitive layer for hydrogen detection is presented. In this approach, the sensitive layer is deposited on the core of a multimode fiber, after removing the optical cladding. The light is injected in the fiber with a given wavelength and all fiber modes are equally excited. The intensity modulation at the fiber output is measured to estimate the presence of hydrogen absorbed by the Pd, and consequently the Hydrogen concentration in the environment. The sensor response depends on both the Transverse Magnetic (TM) polarization (magnetic field perpendicular to incidence plane) and the Transverse Electric (TE) polarization (electric field perpendicular to incidence plane). The response for the Transverse Electric polarization is opposite with respect to the Transverse Magnetic polarization. The objective here is to optimize the Pd-SPR hydrogen sensor design in order to increase its sensitivity. We introduce an analysis of the sensor response as a function of the Pd thickness. Finally, a new design based on a multilayer system is proposed to enhance the SP 'effect'.

Adding flashlights at crosswalks may make these weak traffic points safer. Unfortunately plugging in traffic lights into the electrical grid is expensive and complex. This paper reports about the energetic, the electronic and the optical design and building of a wireless and batteryless biflash installation in the framework of a flemish SME supporting program. The energy is supplied by a small solar panel and is buffered by supercapacitors instead of batteries. This has the advantage of being maintenance free: the number of charge-discharge cycles is almost unlimited because there is no chemical reaction involved in the storage mechanism. On the other hand the limited energy storage capacity of supercapacitors requires a new approach for the system design. Based on the EN-12352 standard for warning light devices, all design choices were filled in to be as energy efficient as possible. The duty cycle and the light output of the high power led flashlights are minimized. The components for the electronic circuits for the led driver, the control and the RF communication are selected based on their energy consumption and power management techniques are implemented. A lot of energy is saved by making the biflash system active. The leds are only flashing on demand or at preprogrammed moments. A biflash installation is typically installed at both sides of a crosswalk. A call at one of the sides should result in flashing at both sides. To maintain the drag and drop principle, a wireless RF communication system is designed.

The five axis goniospectrometer at the National Institute of Standards and Technology (NIST) measures the spectral reflectance of colored samples over a wide range of illumination and viewing angles. This capability is important for the colorimetric characterization of complex materials, such as gonioapparent coatings or retroreflective surfaces. To improve the efficiency of the goniometer, a broad-band source with a matrix-based stray-light corrected CCD based spectrometer was implemented. This new configuration offers a significant reduction in the measurement time allowing for the complete characterization of the goniodistribution of complex materials. Shorter measurement time reduces the load on the precise mechanical assembly, to ensure high angular accuracy over time. Special care was taken to extend the effective dynamic range of measured intensities in the multichannel detection mode to the values of 10⁶ - 10⁷ needed for the characterization of colored samples. The expanded uncertainty of the measured Bidirectional Reflectance Distribution Function (BRDF) for this new setup is about 0.5 % (k = 2) which is comparable to the uncertainty levels of the instrument operating with monochromatic illumination and a silicon photodiode. To validate the new system configuration, the measured BRDF or spectral reflectance factors (R) of test samples were compared with different instruments and we found an agreement of about 0.5 %.

A new class of ordered structures that exhibit exceptional properties not readily observed before in nature or in the laboratory is called metamaterials. Their properties arise from qualitatively new response functions that are not observed in the constituent materials and result from the inclusion of artificially fabricated, intrinsic and extrinsic, lowdimensional components. Low-dimensional or nanostructured Si materials as, for example, nanoscale Si-layered systems combined with an active interface with its crystalline defects show new PV behavior never observed before in nature and in engineering. To observe such nanolayers buried within a Si single-crystal one has to conserve a local strain that plays an important role in the metamaterial formation. To do this, one uses techniques based on X-ray spectroscopy or more recently proposed SEM and EDS images of just cleaved edges. The microscopy results of layered structures have been compared with those obtained from reflectivity simulations from our code based on Lorentz-Drude theory and experimental reflectivity measured in integrated hemispheres. An excellent agreement can be observed.

Layered semiconductor structures like delta-dopings and buried amorphizations, where modified optoelectronic features result simultaneously from material composition and from device design, can considerably widen optoelectronic applications of conventional materials. Multi-interface novel devices (MINDs) based on a nanoscale Si-layered system buried within the heavily P-doped Si wafer have an unusual reflection, absorption and internal light propagation, which can be dominated by a dense free-carrier gas confined within a surface potential well. First, a model of optical functions of the heavily doped Si:P using experimental data published previously for extremely heavily P-doped Si using the Transition Matrix Approach (TMA) to simulate the electromagnetic optical response and field propagation has been constructed. The dielectric function combines oscillation functions and a dense free-carrier gas (Lorentz-Drude approach) and can take into account an inhomogeneous P-doping distribution. Next, an optical model of the real multi-interface device, based on electron microscopy data, has been constructed. A simplified sequence of buried, optically active interfaces and corresponding layers (with transformed material and refraction indexes) is possible due to a planar geometry. Finally, we compare our simulated and experimental reflectivity. In this way we could determine particularly difficult-to-measure parameters. The method presented could be useful for device characterization during the fabrication.