This PDF file contains the front matter associated with SPIE Proceedings Volume 10693, including the Title Page, Copyright information, Table of Contents, and Conference Committee listing.

Optical laser-scanning systems generally contain a scanning lens, like an f-theta lens, to enable a planar imaging field. However, commercially available f-theta lenses show limited working distances and scan fields, while their lens diameter rapidly scales with the scanning range giving rise to bulky lens systems. Therefore, we propose a novel scanning lens configuration, based on a compact tunable lens system, generating a planar imaging field within scanning configurations that require broad scanning fields at large working distances. Particularly, we developed a refocusing illumination lens system, comprising a voltage tunable liquid lens positioned in the centre between 2 passive aspherical lenses. Our novel developed optical system is implementable between the laser source and scanning mirror in a polygon laser-scanning system and ensures a constant spot size along a 640 mm scanning line at a working distance of 900 mm. The voltage tunable liquid lens (Arctic 316 lens of Varioptic) enables to adapt the focal length by the application of a voltage, while the passive aspherical lenses allow to enlarge the working distances and to correct for aberrations. We obtained a compact lens system (system length of 71.8 mm) showing a tunable back focal length between 1078 mm and 1134 mm and 1/e² spot diameters between 229 μm and 238 μm along the scanning line. Furthermore, we successfully demonstrate the performance of our simulated advanced refocusing illumination system in a laser-based scanning configuration, indicating its potential for integration in industrial scanning systems operating at large working distances while requiring large scanning fields.

One of the most interesting problems in the illumination research community is the design of optics able to generate prescribed intensity patterns with extended input sources. Such optics would be ideally applied to the current generation of extended, high-brightness, high-CRI LEDs used in general illumination, allowing reduced size of luminaires and improved efficiency. But in 3D, for non-symmetric configurations, how to design optics for prescribed intensity using extended sources remains an open question. We present an alternative approach to this problem, for the case of extended Lambertian sources, in which the design strategy is based on the definition of selected “edge wavefronts” of an illumination system. The extended emitter is represented by input wavefronts originating from selected points belonging to its edge; the prescribed intensity pattern, instead, is put in relationship with specific output edge wavefronts. The optic is calculated by requiring that it transforms the input edge wavefronts exactly into the output ones. This wavefront-matching procedure can be achieved, for example, with the Simultaneous Multiple Surfaces method (SMS). We show examples of freeform optics calculated according to the above procedure, which create non-rotationally symmetric irradiance patterns out of extended sources. A fine tuning of the output design wavefronts allows accurate control over the uniformity and extension of the output patterns, as well as on the definition of cut-offs and intensity gradients.

Light shaping optics often generate continuously varying or homogeneous far-field distributions: Diffusers or free-form beam shapers are well-suited for transforming a given incident angular distribution into a continuous far-field distribution, while etendue conserving fly´s eye condensers excel in producing homogeneous top-hat far-fields, independent of the incident spatial and angular light distribution. The proposed optics combines the advantages of these light shaping optics in generating continuously varying far-field distributions independently from the incoming light distribution while conserving etendue. The light shaping systems consists of a high fill factor tandem microlens array featuring irregular lenslets with individual aperture size and individual decentration of lens vertex and and lens aperture w.r.t. array channel axis. We present design examples to be realized as monolithic polymer-on-glass tandem arrays, mastered by grayscale lithography. Applications of this light shaping approach are LED-spotlights with particular farfield specifications and small design envelope e.g. for automotive or general lighting.

To leave the path of classic holography and limit the space-bandwidth-product of the holographic reconstruction is one way to enable interactive real time holographic 3D displays. Thus, a couple of major problems - among several others - can be reduced to a practical level. This holds e.g. for the computation power, the data transfer rate and the pixel count of the spatial light modulator (SLM) used. Although this idea is almost twenty years old, the maximum time span of IP protection, displays based on space-bandwidth-limited CGH reconstruction, which also can be referred to as spacebandwidth- limited reconstruction of wave front segments, are still not on the market. There are several technological reasons for that. However, the technological barriers can be tackled gradually. One problem to be solved is the illumination of the entrance plane of the preferable complex valued spatial light modulator (CSLM). Here, CSLM means to modulate the phase and the amplitude of each pixel. The display diagonals of desktop and TV type CSLM might be e.g. 32 and 65 inch respectively. In other words, reasonable large collimated illumination wave fields are mandatory. In addition a small form factor is a must have in order to obtain commercial success. The solution is an optical system design, which is based on Bragg diffraction based volume gratings. Classic refractive optics fails here. In other words, Bragg diffraction based volume gratings are key components of illumination units of holographic 3D displays. They can be used within a parameter space, which cannot be addressed by surface relief type diffraction optics. But their layout depends on the parameters of the illumination wave field, which has to be tailored in regards to the optical system of the discrete, e.g. 1D or 2D encoded holographic 3D display. This will be described in more detail. The example used for the description is a double wedge type backlight unit. Furthermore, it will be explained why the use of complex valued secondary light sources is a must have in holographic 3D displays. For this, a short explanation of coherent retinal inter object point cross talk will be given too. Finally, the description of the wave field shaping (WFS), which is required in order to form the optimized complex valued light source planes, is provided. In other words, a description of a tailored coherence preparation is given, which is up to now not state of the art. The cause and effect relationship of the light propagating from the primary light sources, which are lasers, to the final receptor, which is the retina, will be pointed out. Although this tailored partial coherent illumination totally differs from the state of the art of information displays, it might help to understand a technology, which will come in the next decades.

Two freeform surfaces provide more degrees of freedom in designing illumination optics and can yield a better solution. The existing methods for point-like sources are mostly valid in designing one freeform surface. Designing two freeform surfaces for point-like sources still remains a challenging issue. In this letter we develop a general formulation of designing two freeform lens surfaces for point-like sources. The proposed method is very robust in designing freeform lenses with two elaborately designed surfaces. The examples clearly show that using two freeform surfaces yields better solutions to challenging illumination problems with ultra-high energy efficiency.

Designing freeform optical surfaces with a large number of degrees of freedom has been a field of extensive research and development. Several design methods have been proposed. Starting point in the design process often is an idealized light source that has zero étendue (e.g. point source or collimated light). With this assumption the solution is unique and corresponds to the solution of an equation of Monge-Ampère type. We propose a method to solve the Monge-Ampère equation on convex bounded domains by using triangle meshes and by minimizing the difference between prescribed and actual target light distribution which is computed by tracing rays through the optical surface. The mathematical solution has to comply with two conditions: the boundary of the source domain has to be mapped onto the boundary of the target domain and the solution has to be convex. The boundary condition problem is solved using a signed distance function that is computed in advance by a fast marching algorithm. The actual light distribution is computed by tracing rays along the triangle nodes and computing the light irradiance on the target by dividing the light flux through a triangle by its mapped area on the target. Under certain conditions this is also an approximate solution to the Optimal Transportation Problem with quadratic cost.

Modern illumination applications increasingly require adapted non-symmetric light distributions. Examples can be found in street lighting, architectural lighting, and also in more technical applications as automotive lighting. From an optical design aspect this leads to an increasing need for freeform lens design. Even though some design methods for freeform surfaces exist, the development of non-symmetric illumination solutions is still challenging. We investigated the applicability of the Cartesian oval method for the design and production of lenses with customized light distributions in Suprax glass. Of importance are both the manufacturability and the usability with extended LEDs. In the following paper we will show the basics and implementation of this method also using GPUs and discuss the pros and cons in the context of the usual requirements of illumination projects.

In this contribution we introduce the Monge-Ampère equation, defining the shape of a freeform surface, for several optical systems. We restrict ourselves to systems containing one or two freeform surfaces. As numerical solution method we propose a least-squares method, which is a two-stage method. In the first stage the optical map is computed, and subsequently in the second stage, the shape of the optical surface(s). We demonstrate that our method can handle complicates source and target distributions.

A design method of two coupled freeform surfaces for the control of the irradiance and phase of the input and output wavefronts without the restriction to paraxiality or spherical/planar wavefronts is presented. It can be applied to the design of coupled lens surfaces, coupled mirrors or the combination of lens and mirror surfaces. The method is based on the description of the freeform surfaces through a system of coupled partial differential equations (PDE) for the first freeform surface and a ray-mapping projection. By calculating the required output wavefront between two predefined complex illumination patterns, we demonstrate that the presented algorithm can be applied directly to the calculation of a single optical element for the generation of two different irradiance distributions on separated target planes. Additionally, a manufacturing analysis of the corresponding freeform surfaces of a double lens system is provided. Furthermore, an extension of the design approach for a single freeform lenses with a predefined entrance surface from [J. Opt. Soc. Am. A 34, 1490-1499 (2017)] to single freeform lenses with a predefined exit surface is presentend. Limitations of the design method and possible improvements are discussed.

Road lighting can benefit strongly from LEDs and freeform lenses. However, freeform lenses design for road lighting applications is complicated and difficult when balancing energy efficiency and lighting quality. In addition, the asymmetric properties of the required light distributions and non-neglectable sizes of LEDs make the design more challenging. Currently, we prefer an efficient design strategy with two steps: light distribution optimization and freeform lens construction. In the first step, we employ a modified polynomial representation of the illuminance distribution and perform constrained optimization. In the second step, we construct the freeform lens with double freeform surfaces to realize the optimized light distribution using the ray mapping method associated with over compensation.

Given the high source luminance of current white LEDs, spreading this luminance in order to avoid glare, is a crucial aspect of effective LED lighting system design. In previous work, a method has been presented to design a rotational symmetric or extruded lens consisting of different freeform segments. These segments are designed in such a way that they spread the incoming rays into multiple overlapping fans of which the combination forms a desired target intensity pattern. The advantage of using freeform lens segments is that these can be precisely tailored to different target intensity patterns, e.g. intensity patterns with a sharp cut-off. The transformation of the incoming intensity distribution to the target intensity distribution can be seen as a linear transformation. If the source and target distributions are discretized into a finite number of bins, it is possible to represent this transformation as a matrix. With an iterative procedure one can quickly generate such transformations for specific source and target distributions. The spreading of light at each point of the optical surface can then be realized with small freeform lens segments. These individual freeform segments can be implemented in two different ways, convex or concave. In this paper, the case is considered in which convex and concave freeform structures are alternated which allows for the creation of a continuous, smooth, oscillating lens surface. This approach can improve both the performance and manufacturability when compared with a discontinuous surface. A drawback of the approach is the fact that one loses control over the overall form factor of the resulting lens. The derived iterative procedure was used to design a luminance spreading illumination lens with smooth, wavy structures on one side and a flat surface on the other side. The lens was designed to generate a specific wide-beam target intensity distribution when combined with a high-brightness LED.

The strive for the small volume and light weight in head-up displays has made the conventional configuration combining relay optics and combiner unpractical any more. In this paper, a compact and light-weight head-up display with a large eyebox is designed, with two orthogonal geometrical waveguides adopted to extend the exit pupil in both directions. This two-dimensional waveguide acts as a pupil expander, which can also save the whole system from the trouble of severe aberrations. A triangular prism serves as the input-coupling and the partially reflective mirrors array is used as the output-coupling. Parameters to shape the combined waveguide are derived. The spherical surface based coaxial projection system to match the combined waveguide are designed to project and magnify the virtual image onto a surface at infinity. The compact head-up display integrating projection optics and the combined waveguide has a horizontal field of 20°, with an eyebox of 80 mmx80 mm.

Many optical devices have certain light diagrams, which correspond to the world standard. However, to achieve this, one can use a lens including the freeforms, which provide necessary geometry for the light distribution. Freeform surfaces have additional capabilities that may provide a better solution to the asymmetry problem with higher efficiency or fewer elements. This method implies that we know the type of source and the light distribution. In the paper various types of freeforms are considered. Results of freeform modeling forming required light distribution for a given optical source are presented. Effective methods of freeform modeling using Zemax (OpticStudio) are discussed.

Free-form optics have been proven to be a very powerful and efficient illumination strategy with applications ranging from automotive and architecture illumination to laser beam shaping. State of the art free-form optics design methods assume that the light has zero étendue, which is for example given if it is emitted from a point source or perfectly collimated. In some cases, this assumption is not valid and designing free-form optics with a zero-étendue method and using a non-zero étendue source will result in a blurring effect for sharp edges in the irradiance pattern. In previous work1, we derived an integral formulation for the irradiance distribution on a target screen for a non-zero étendue source. Furthermore, we showed for a 2D-application that it is possible to combine this irradiance calculation method with a surface optimization routine to obtain free-form optics that also take into account a non-zero étendue. As a continuation, we extend this approach to three dimensions. To this end, we show how the integral formulation can be approximated numerically in three dimensions and we present an optimization method for the free-form optics. We demonstrate the performance of the algorithm by using two different test cases. For the second test case, we additionally present how the achieved irradiance distribution varies with the étendue of the source.

Illumination optics is a multidisciplinary effort: a good optical engineer should understand the language of physics, mathematics, computer science, materials science, process engineering, cost engineering, psychology, visual perception, marketing, design, lighting standards and regulations. The transition to LED lighting changed the rules of optical design in most of these aspects. The absence of IR and UV light enabled the use of plastic optical components, which allows for a huge variation in optical solutions. This in turn completely changed the appearance of the luminaires and allowed for more precisely trimmed intensity distributions. When these new luminaire types entered the market, people started to question whether the lighting standards, which were defined in the days of fluorescent tubes and incandescent lamps, were still valid for LED-based luminaires. These changes will be illustrated with optical designs of office lighting luminaires. The impact of LED-based luminaire designs on discomfort glare perception and glare standards will be addressed.

In this work, we explore methods to create arbitrary spectra efficiently with high precision and accuracy using multichannel LED light engines. We propose an optical feedback controller using integrated optical sensors, namely spectrophotometers and colour sensors, for real-time monitoring of the emitted light and for effective spectral corrections. Our results show that the such kind of close-loop systems can be used to obtain relative spectral errors and ▵uv' between target and emitted spectra significantly below threshold values, ▵uv' < 0.002 in all cases.

Aplanatic optics were invented over a century ago, motivated principally to achieve high-fidelity imaging in telescopes, microscopes and cameras. Aplanats are designed to completely eliminate the two leading orders of geometric aberration - spherical and comatic - and the simplest designs comprise two contours that can be reflective and/or refractive. Aplanats of high radiative efficiency can also approach the thermodynamic limit to flux concentration and light collimation - of particular value in nonimaging applications such as solar energy collection, light-emitting-diode collimation, and infrared technology. Recently, it was discovered that the original aplanatic mirrors and lenses cover only a small spot in a rich landscape of fundamental categories of optical devices, which opened a broad spectrum of powerful new designs. In this presentation we review these advances, and summarize the complete classification schemes that have now been elucidated for aplanats. They include examples of practical designs for achieving radiative transfer near the thermodynamic limit in flux concentration and irradiation applications, based on dual-mirror, dual-contour lens and lens-mirror combinations. The representative designs that are illustrated also include the most recent progress in Fresnel (faceted) aplanats, motivated by the quest for progressively more compact optical systems, as well as examples of hybrid designs – combining aplanats of different classifications for enhanced performance.

A new family of lighting products is developed as laser diodes replace LEDs in the remote phosphor configuration. The resulting lighting systems, also known as laser-excited remote phosphor systems, exhibit advanced characteristics compared to LEDs, such as significantly higher luminance and smaller étendue. However, the bottleneck in their performance is often considered to be the conversion process within the phosphor layer. The high-intensity exciting laser beam in combination with the low thermal conductivity of ceramic phosphor materials leads to thermal quenching, a phenomenon in which the emission efficiency decreases as the temperature rises. In order to investigate the thermal limitations and derive the optimization parameters for these systems, the simulation strategy proposed here effectively takes into account the interplay between the thermal and optical effects. The time-dependent heat equation is solved based on the system’s energy balance equation, while the optical effects are modeled within the geometrical optics regime using a ray tracing algorithm. The coupling is achieved considering the temperature-dependent quantum yield (or efficiency) for the phosphor material. For simulation purposes the phosphor material can be considered as a bulk diffuser; the bulk scattering properties are introduced: the absorption and scattering coefficients as well as the scattering (or phase) function. The two-term Henyey-Greenstein function is adopted as scattering function here, since it combines computational efficiency and accuracy. To conclude, an opto-thermal simulation scheme is required for the optimization of a phosphor-converted lighting source. Efficient device design can contribute to the advancement of green lighting technology, a step towards meeting the environmental challenges of our age.

Several investigations have been performed in the field of designing a lens-array for LED signal lighting applications. Solving the parabolic Monge-Ampere (PMA) equation to design the required lens-array leads to problems in matching the boundaries of the lens-lets. Therefore, considerations should be taken into account while generating the mapping adaptive grids. In this paper, we focus on the mathematical investigations of the numerical solution of the PMA equation for the steady state solution, as it is one of the state of the art methods. The first objective is to use the solution of PMA equation for generating the adaptive grid. The second objective is to test the quality of the light-energy mapping by applying the Monte-Carlo simulation to the generated adaptive mesh grid. The last objective is to use the resulting mesh grids in designing a lens-array for signal lighting applications. The paper starts by presenting the difference between signal lighting and optical illumination. Then, an explanation of the advantages of using the beam-let transformation concept in the optical systems designs which is the motivation for us to investigate the solutions of the PMA equation. After that, procedures of generating the adaptive grid are discussed. Also, results of the Monte-Carlo simulation are presented to evaluate the quality of the generated grid. Finally, the problems of using the generated grid for designing a lens-array are discussed, including an approach to control the light-energy mapping to design the boundaries of the optical surfaces as a part of our future investigations.

In this contribution, we introduce a novel light source allowing to generate multiple collimated light beams of which both the spatial location of the origin and the direction can be controlled. The realization of such a light field generator is based on a high-resolution display on top of which a micro lens array is mounted in the distance of its focal length. Consequently, the micro lenses emit collimated light beams if one of the underlying pixels is turned on. In order to be able to turn on a light ray originating from a certain macro pixel with a certain direction, a mapping from a two-dimensional spatial macro pixel coordinate and a two-dimensional angular coordinate to the two-dimensional coordinate of the respective pixel of the underlying display is needed. In our paper, we solve this calibration task with a suitable optical setup and appropriate processing methods. As an example application, we demonstrate how our prototype can successfully be used for the visual inspection of transparent objects by means of the inverse light field illumination method.

Projector based augmented reality serves as an alternate visual guidance tool for surgeons when performing complicated open surgeries. In projector based augmented reality, image overlay projection is a technique that allows the surgeon to view the underlying anatomical information such as tissues, tumors etc. directly on the surface of the organ or the patient. This will provide an intuitive view of the surgical navigation data by combining the surgeon’s real world view with the preoperative three dimensional virtual models or instructions. Thus the strain on the surgeon to mentally align and visualize the preoperative data with intraoperative scene is greatly reduced. There are multiple stationary and handheld projectors available in the market today for this purpose. During surgery, stationary projectors mounted on a rack or under the ceiling suffer from a loss of adjustability and further cause shadowing issues when the surgeon occludes the scene. Although hand-held projectors do not have these disadvantages, they have major problems in terms of illuminance and luminous flux. The amount of light at which the hand-held projectors can project virtual additional information on to the patient is very low especially when the surgical lights are switched on. This paper therefore aims to provide an analysis of the requirements for designing such a special hand-held, augmented reality projector system that could be used during surgery, through a user study. Various optical parameters which are a key to design an augmented reality projector such as illuminance, luminance, luminous flux etc. are measured. Apart from that, other parameters such as refresh rate, image size, resolution which are also some important criteria in designing such a special projector, are discussed in this paper with respect to our application.

In a pressurized water reactor (PWR) there are no light sources due to the operation of such devices in a given medium. Thus, in order to obtain a high-quality video image when operating on PWR, the lighting unit must be located on the optoelectronic manipulator transmission device. The subject of the study is optoelectronic systems designed to monitor fuel loading underwater in PWR. The relevance of the topics is image quality improvement of the object under a high level of radiation background, the use of a new radiation-resistant block of illuminators, the main light source of which are LEDs, the development of a control circuit for the LED lighting unit using a microcontroller. For LED lighting optical systems' design, it is proposed to use nonimaging optical elements with refractive and reflective surfaces of various shapes. For their calculation, the known methods which are developed for the calculation of spherical and similar aspheric optics are not applicable. The scientific novelty of the work is the use of LEDs made on carbide-silicon substrates in radiation-resistant television systems.

Automotive lighting presents a challenging and interesting illumination design space. In addition to non-trivial intensity distribution test specifications, automotive lighting is also increasingly important for communicating stylistic details. Light guides, in which light is introduced at one or both ends and then is extracted at roughly orthogonal angles to the path curve, allow a great deal of aesthetic freedom, and are therefore well suited to automotive lighting tasks that need to convey a brand’s image-for instance, daytime running lamps, tail lamps and turn indicators. Light guides can also help minimize the number of sources and parts needed to create a desired light distribution; or may facilitate a more favorable source placement from a packaging point of view, making them even more attractive for these lighting solutions. Optical designs for automotive light guides are challenging and consequently time consuming. This problem is exacerbated by increasing complexity due to new styling demands, higher expectations for perceived uniformity from multiple viewing directions, and the desire to reduce required source power. In this paper, we describe a new software approach to automatically creating and optimizing light guides with prismatic extractors in a CATIA environment [1]. Often the light guide path curve has a complex shape, and the light guide’s extractor surface must be oriented such that it is opposite the desired light direction. The cross section of the light guide is often partially circular, but other shapes may also be used. Additionally, extractors, which can be bumps or holes, need to be created and oriented appropriately on the surface, and key geometrical parameters that are related to optical performance must be easily changed. Our approach leverages the powerful CATIA environment to construct the light guide geometry. Light sources, ray trace simulations, optical material properties, and optical sensors are also added directly into the CATIA model. Furthermore, many types of optical analysis can be performed after Monte Carlo rays are traced. For instance, one can examine the intensity distribution and select specifications against which to measure test points. Luminance camera, ray history and ray file sensors are also available. Using Monte Carlo ray trace results, the light guide prism geometry is automatically optimized to achieve a desired spatially uniform (or deliberately non-uniform) light distribution. At the same time, the angular distribution is optimized by adjusting prism face angles to point light towards defined angular centroid targets. We employ a binning concept that splits the light guide into sections along its length. Prisms in each bin are associated with the light distribution nearby and are adjusted so that the light from the associated bin has a specified relative flux within a cone, as well as a specified centroid pointing direction. In many cases, the source is only on one end of the light guide; however, in some situations, sources at both ends are needed. Other design considerations include fillet radii, prism face curvature, and draft angles. We provide design examples in the paper.

Car interiors have been evolved towards the so-called driver working place and in future to (autonomous) cars as third living space for leisure and work. Entertainment systems, driver assistance, large displays, and light design have revolutionized the design as well as the expectations of drivers and passengers. Material, displays, and ambient light will create a new environment for passengers in the future. This paper focuses on advanced interior lighting by a new integrated smart embedded LED (ISELED) concept which enables beyond state-of-the-art light effects including contour lighting and daylight visibility at reduced effort compared to today’s LED interior lighting approaches. The ISELED concept is an open alliance eco-system along the supply and value chain. Major automotive lighting trends as well as challenges and solution will be described.

In general lighting and some applications of automotive lighting, there are advanced requirements on light distributions. Illuminance should have a uniform course at different distances from the luminaire. As well disturbing colored borders of the distribution should be prevented. In the case of lens-based or catadioptric illumination systems, the light guidance takes place wholly or partly via refractive optical elements which leads to an inherent chromatic aberration. In the area of imaging optics, lenses with negative and positive powers made from different materials are combined for chromatic correction. If optical glasses are available for realization, systems with very good color correction can be designed. For cost reasons, however, classic concepts using optical glasses are excluded. Marketable materials are optical polymers, with low refractive index and midrange Abbe number. To understand the genesis of chromatic aberration, it is crucial to analyse every possible light path of the system. If a system has enough free parameters, one can optimize light paths due to their impact on chromatic aberration. Our goal is, to follow this approach concerning a purely refractive aspherical lens system without the usage of scattering structures.

A freeform LED lamp that meets the requirement of street light distribution is presented. The illumination system shows high uniformity and low glare. The prototype of this freeform is simple based on 3D modeling in LightTools. The lens is mounted on a chip-on-board (COB) LED as the luminaire with inclination to meet the requirement of CIE standard for different types of road lighting arrangement: one-sided arrangement below (one-sided arrangement above), double-sided mirrored arrangement and double-sided staggered arrangement. Also, the sensitivity analysis is performed for considering real installation.

Recently laser technologies are expanded widely among various applications of optical devices. Regarding unique properties laser sources are used in industrial systems, in medicine, in a variety of laboratory equipment, etc. Large number of technical applications requires laser beam reshaping, which presuppose redistribution of optical power in the beam cross-section; particularly to form a flat-top beam with uniform intensity distribution. Traditional inverted lens telescopic systems purposed for the light collimation do not allow to achieve the laser beam reshaping. For this case is possible to use more complicated kind of lens surfaces, such as aspherical ones, or freeforms (both lens and mirror optical systems), microlens arrays and other approaches. Current work describes the optimization model of laser beam reshaping optical system based on aspherical (conic) optics, using Zemax software. Single and two-lens telescopic systems were investigated to reach specified characteristics, results of this studies are shown.

A physically accurate description of the optical properties of surfaces is the one of the most important requirements in optical simulation for both imaging and non-imaging optics. Uncertainty in the specification of the optical properties might influence the simulation image or the spatial distribution of radiation in optical system. One of the ways of describing the optical properties is using the Bidirectional Scattering Distribution Function (BSDF). As a rule, BSDF is measured by goniospectrophotometers, but sometimes it is not possible to perform such measurements. In some cases, the measurement should be done inside the material, but it is impossible to measure BSDF of the boundary there. One of the possible solutions is to measure the microrelief heights distribution by profile measurement machine or atomic force microscope and assign measured data for given model. But, not every optical design software solution has the ability to specify microrelief directly, while majority of them just have the ability to specify BSDF. In this article, authors show methods of BSDFs generation from measurements of the real microrelief in the form of spatial distribution of heights.

Lighting design or stray light simulation of imaging or non-imaging optical systems requires a precise specification of the optical properties of the scattering materials and one of the ways of the proper specification is the Bidirectional Scattering Distribution Function (BSDF). Although, it is possible to obtain data about the optical properties of the sample for example by measurement of the BSDF, but it is difficult to extract the properties of the sample components (BSDF of the sample boundary, parameters of volume scattering, etc.). In such cases, it is required to reconstruct these properties. For this operation, there are many methods, like the reconstruction of the BSDF of the microrelief, but they not applicable in cases when the volume scattering is used. Authors have developed a method for optimization of the volume scattering media parameters, which shows good agreement with the measurements of the sample BSDF.

Nuclear power is the rapidly developing branch of the global energy sector as nuclear-based electric power generation is 11 percent of total electricity production in the world. However, any mistake during the nuclear power plant maintenance may lead to technological disaster. In order to provide technological safety at the nuclear power plant it is necessary to carry out video diagnostics of nuclear reactor. Although modern optoelectronic systems have good light sensitivity, reactor walls illumination is too low, so diagnostic video systems need artificial light source to provide the necessary signal-tonoise ratio. There are special requirements to the light sources radiation tolerance, lighting uniformity, spectral characteristics Thermal stability, dimensions and weight characteristics are also of great importance. Light-emitting diodes (LED) based luminaire with radioactive shielding and heat removal system seems to be the good way to perform the task of illuminating the walls of nuclear reactor. The advantages of the LED based luminaires in comparison with other light sources are their relative energy efficiency, stability and long lifetime. The aim of the paper is to design the LED luminaire to perform the tasks of nuclear reactor video diagnostics, considering the high radiation and temperature level when choosing the materials and design. The computer modeling is carried out and its results are discussed.