Polarization maintaining fibers arrays are key enablers to process high bandwidth data, representing a powerful part within the photonic integrated chip technology. The different channels increase the information density and allow to multiple singles through one fiber bulk at the same time. Due to fiber's small dimensions (empty set125 mu m) they can be integrated in existing infrastructure easily and are very flexible at the same time. However, the compact design together with the flexible material properties demands for new precise tools and technologies to reach the necessary precision during packing. The Fraunhofer-Institute for Production Technology IPT develops, together with their partners Phix and Aixemtec, new handling and assembly tools, as well as processes as one of the leading companies in this field. In the self-developed assembly cell, the fiber handling tool-head operations automatically to pick up, manipulate and tack single fibers to a glass plate or fiber to chip. Each fiber is moved by a portal robot within the assembly cell with micrometer accuracy but also can be rotated with a repetition accuracy less than 0.01 degrees. Advanced illumination units observation techniques allow to package fibers arrays much quicker and more robust than before. Therefore, additional camera systems and material characteristics are used to develop smart alignment routines. As a result, the observation of the orientation of the PM-fiber core as well as the fiber layout during the assembly process leads to high quality products within fast production cycles. Due to the flexible construction of the assembly call also PIC packaging and fiber-to-chip coupling is possible.

Manufacturing equipment for novel products needs to be operational within days to weeks, prototyping should be done in an instant and create a basis for consecutive quick implementation of small-series production and the following scaling of production.

Digital Twins enable the analysis of systems under real world conditions using multiphysics models, sensors and bidirectional data connections between the digital and the physical twin. At the core of the Digital Twin lies the three-dimensional geometric representation of the system. The paper presents a method to enhance the level of symmetry between real and virtual space and create geometric twins of parts. The proposed method unifies the 3D CAD model with selected real measurements to generate as-manufactured geometric representations. The generation is automated using modification algorithms and based on the STEP data format of the international standard for product data representation and exchange (ISO 10303).

Miniaturization and price decline enable the integration of information, communication and sensor technologies into virtually any product. Products become able to sense their own state as well as the state of their environment. Paired with the ability to process and communicate this data allows for the creation of digital twins. The digital twin is a comprehensive digital representation of an individual product that will play an integral role in a fully digitalized product life cycle. To prove the digital twin concept a cyber-physical bending beam test bench was developed at DiK research lab.

Digital Twin (DT) is being considered a significant enabler for Industry 4.0 initiatives. Within Industry 4.0, the amount of digital product information generated and collected over the entire lifecycle has been growing. Current information and communication technologies, including data storage, data processing, and wireless data transmission, may be leveraged to digitally mirror the lifecycle of a corresponding physical product with increasing level of detail. A DT creates a link between physical products and their virtual models with more comprehensive data and accumulation of knowledge. Therefore, a DT may be applied to enhance simulation, traceability and to support the offering of value-added services along the lifecycle. However, the definition of a DT and its requirements are not yet fully established. The characteristics a DT model should possess to be widely used in manufacturing remains an open question in the literature. The concept is still broad and dependent on the lifecycle stage and industry sector of application. Therefore, the objective of this paper is to propose an initial synthesis of DT requirements based on a literature review and industry interviews. The literature review focuses on the content analysis of papers published from 2010 to 2018 and indexed in the ISI Web of Science database. The interviews were conducted with industry representatives in Brazil. The results show that DT requirements are related to real-time data, integration, and fidelity. Besides, it shows that industry requirements are close to literature and the actual implementation of DT is the future of research in this field.

Digital Twin technology is increasingly gaining importance for digitizing industry. Even if digital twin technology still needs fundamental research, its significance for industry has become very visible, as digital twin technology is a key success factor to professionalize Cyber-Physical Systems (CPS) applications. Industrie 4.0 as an initiative to increase industrial added value is based on establishing connectivity between CPS and to enable communication between CPS. The industrial application scenarios for Industrie 4.0 aim at vertical and horizontal life-cycle integration concepts where digital twin technology plays an important role. This contribution explains major concepts of Industrie 4.0 and derives the role of digital twin technology. Furthermore, digital twin approaches are presented and as well as the proposal to use the STEP-technology (Standard for the Exchange of Product Model Data, ISO 10303) as a fundamental basis for a comprehensive digital twin technology.

Modern sensor technology and decreasing hardware costs enable the collection of a wide range of data. Nonetheless, the collection of data itself does not generate value. The collected data must be processed and analysed. Many small and medium-sized enterprises already collect a number of data. However, there is no definite strategy, which data needs to be collected in order to acquire relevant insights into processes. The enormous potential of data analysis and the current lack of its implementation caused the development of this framework. It will assist enterprises to evaluate their own level of digitalization to assess resource use. (C) 2018 The Authors. Published by Elsevier B.V.

Mastering the process of dispensing is one of the key enablers for high-precision optics assembly. Industrial dispensing mainly needs to solve the problems of droplet volume control as well as droplet positioning. Both aspects are of high importance in order to achieve a highly repeatable assembly processes. For that purpose, AIXEMTEC has developed a machine-integrated calibration module. AIXEMTEC is provider of a modular platform for automated optics assembly consisting of integration platforms, tools for manipulation, dispensing and machine vision as well as modules for tray handling, special-purpose metrology and others. After a brief overview of the jet-dispensing technology and the dispensing tool used within the machine, this paper introduces a calibration module for contact-less dispensing systems. The calibration module implements an image-based approach synchronizing image acquisition with droplet release. This calibration module allows for machine-integrated closed loop calibration of the volume in sub-nanoliter-range as well as the horizontal position of droplets. Both control variables have been benchmarked and results will be presented in the paper. The calibration process will be outlined. The paper closes with the description of a typical application that benefit from machine-integrated droplet calibration.

Digital Twins enable the analysis of systems under real world conditions using multiphysics models, sensors and bidirectional data connections between the digital and its physical twin. At the Research Lab of the Department of Computer Integrated Design (DiK) of Technische Universität Darmstadt, a Digital Twin demonstrator was developed that enables a motion-structural simulation of a bending beam test bench. The approach provides proof of many of the claimed benefits and challenges through a comprehensible Digital Twin system.

Current technological advances pave the way for highly flexible production processes within Cyber-Physical Production Systems (CPPS). In a CPPS, every component being produced may be represented by a virtual data model containing its own unique information. Components are also information carriers with communication features enabled by an Internet-based exchange of information. The exchange of information between components and with the production system may happen over the whole manufacturing process. The availability of detailed information about every component supports the implementation of optimized assembly processes, called Smart Assembly of smart components. Smart Assembly is an approach to assembling different components according to unique specifications of every product variant, and considering the most efficient combination of components for each assembly. Therefore, a structured component data model considering data storage and data access is needed. However, for the Smart Assembly of smart components, the underlying data structure and processes have to be developed. The objective of this paper is to propose a data structure to enable the Smart Assembly of components in an assemble-to-order production scenario. To achieve the proposed objective, two use cases have been developed to simulate the Smart Assembly of smart components.

The quality of High Power Diode Laser (HPDL) systems highly depends on the assembly precision. Nowadays, neither the precision of the manipulation tools (step resolution < 10 nm) nor the measurement systems utilized in active alignment algorithms (alignment precision of ~50 nm) are the quality limiting factors but the bonding process is. This is due to the volumetric shrinkage of fast curing UV-adhesives in the curing process. The objective of this work is to minimize the absolute volumetric shrinkage of the UV curing adhesives between edge emitter and bottom tab so no significant misalignment while curing is expected. The approach was first described in the paper [SPIE 10086-28] and aims for minimizing the glue gap and therefore the amount of adhesive through combining active alignment of fast axis collimators (FAC) to edge emitter with a tolerance compensated individualized FAC on bottom tab subassembly in a fully automated production process. With less adhesive the absolute volumetric shrinkage is reduced. The expected benefits are the reduction of the misalignment through volumetric shrinkage and a 100% quality assessment without additional costs. Lens quality data such as smile, residual divergence and optical surface imperfections can be characterized. A permanent data collection provides feedback for all previous and following production systems and allows the improvement of the quality for the whole HPDL production chain. This paper presents the results gathered by implementing the individualized FAC on bottom tab process in an industrial production environment and compares it to the expected benefits to conventional HPDL production.

The assembly of optical components for laser systems is proprietary knowledge and typically done by well-trained personnel in clean room environment as it has major impact on the overall laser performance. Rising numbers of laser systems drives laser production to industrial-level automation solutions allowing for high volumes by simultaneously ensuring stable quality, lots of variants and low cost. Therefore, an easy programmable, expandable and reconfigurable machine with intuitive and flexible software environment for process configuration is required. With Fraunhofer IPT’s expertise on optical assembly processes, the next step towards industrializing the production of optical systems is made.

Depending on the application, high-power diode lasers (HPDL) have individual requirements on their beam-shaping as well as their mechanical fixation. In order to reduce assembly efforts, laser system manufacturers request pre-assembled beam-shaping systems consisting of a support structure for adhesive bonding as well as one, two or more lenses. Therefore, manufacturers of micro-optics for HPDL need flexible solutions for assembling beam-shaping subassemblies. This paper discusses current solutions for mounting optical subassemblies for beam-shaping of high-power diode lasers and their drawbacks regarding quality and scalability. Subsequently, the paper presents a device which can be used for the sensor-guided assembly of beam-shaping systems based on bottomtab support structures. Results from test productions of several hundred modules are presented showing that repeatability in the range of 1 μm is feasible on an industrial level.

A unique citation identifier (CID) number is assigned to each article at the time of publication.Utilization of CIDs allows articles to be

The assembly process of optical components consists of two phases - the alignment and the bonding phase. Precision - or better process repeatability - is limited by the latter one. The limitation of the alignment precision is given by the measurement equipment and the manipulation technology applied. Today's micromanipulators in combination with beam imaging setups allow for an alignment in the range of far below 100nm. However, once precisely aligned optics need to be fixed in their position. State of the art in optics bonding for laser systems is adhesive bonding with UV-curing adhesives. Adhesive bonding is a multi-factorial process and thus subject to statistical process deviations. As a matter of fact, UV-curing adhesives inherit shrinkage effects during their curing process, making offsets for shrinkage compensation mandatory. Enhancing the process control of the adhesive bonding process is the major goal of the activities described in this paper. To improve the precision of shrinkage compensation a dynamic shrinkage prediction is envisioned by Fraunhofer IPT. Intense research activities are being practiced to gather a deeper understanding of the parameters influencing adhesive shrinkage behavior. These effects are of different nature - obviously being the raw adhesive material itself as well as its condition, the bonding geometry, environmental parameters like surrounding temperature and of course process parameters such as curing properties. Understanding the major parameters and linking them in a model-based shrinkage-prediction environment is the basis for improved process control. Results are being deployed by Fraunhofer in prototyping, as well as volume production solutions for laser systems.

Today's manufacturers are facing numerous challenges such as highly entangled and interconnected supply chains, shortening product lifecycles and growing product complexity. They thus feel the need to adjust and adapt faster on all levels of value creation. Self-optimization as a basic principle appears a promising approach to handle complexity and unforeseen disturbances within supply chains, machines and processes. Therefore it will improve the resilience and competitiveness of manufacturing companies.This paper gives an introduction to the concept of self-optimizing production systems. After a short historical review, the different levels of value creation from supply chain design and management to manufacturing and assembly are analyzed considering their specific demands and needs for self-optimization. Examples from each of these levels are used to illustrate the concept of self-optimization as well as to outline its potential for flexibility and productivity. This paper closes with an outlook on the current scientific work and promising new fields of action. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

The alignment of optical components is challenging. This paper proposes self-optimisation as a means for reducing planning efforts and increasing the system’s autonomy. Hence, reduced costs and production times can be achieved. Moreover, self-optimising approaches for laser optics assembly enabling autonomous compensation of manufacturing tolerances are presented. Based on ray-tracing simulation, the assembly system carries out the alignment of optics automatically. During the alignment process the laser beam is monitored and analysed. The ray-tracing simulation is updated in a closed-loop manner for gaining information on required correction movements. This information is passed to the assembly system in order to achieve a valid optical function using tolerance-affected components. The choice of metrology as well as the interfaces between different software packages and hardware components will be discussed. The alignment procedure will be described using the example of a miniaturised optical system suitable for laser beam guiding and shaping.

Modern day production has to overcome a polylemma – the gaps between economies of scale and scope as well as between economies of plan and value. Due to shorter product lifecycles and a rising demand of customization, flexibility and adaptability of assembly processes will become key elements for a sustainable success of industrial production in high-wage countries. Self-optimization as presented in this paper has been identified as one major contributor to the enhancement of this flexibility and adaptability. After a short introduction of the historical background, the specifics of the application of self-optimization to assembly are discussed using its meta model. In the end, two application examples are presented to illustrate its industrial deployment.

In the assembly of optical resonators of optically pumped semiconductor lasers (OPSL), the highly reflective resonator mirror is the most crucial component. In previous cooperation, Coherent and Fraunhofer IPT have developed a robust active alignment strategy to optimize the output power of the OPSL resonator using search strategies for finding the laser threshold as well as hill-climbing algorithms for maximizing the output power. Beam-shape as well as the laser mode have major influence on the quality and the duration of subsequent beam-shaping and fiber-coupling steps. Therefore, the alignment algorithm optimizing the output power has been extended recently by simultaneous image processing for ensuring a Gaussian beam as the result of alignment. The paper describes the enhanced approach of automated alignment by additionally scanning along the optical resonator and subsequently evaluating and optimizing the roundness of the beam as well as minimizing the beam radius through twisting and tilting of the mirror. A quality metric combining these measures is defined substituting an M-2 measurement. The paper also describes the approach for automated assembly including the measuring setup, micromanipulation and dispensing devices.