3D Printed Optics and Additive Photonic Manufacturing IV

I will explore various facets of photonic quantum systems and their application in photonic quantum technologies. Firstly, I will focus into quantum foundations and by discuss quantum interference, a key element in photonic quantum technologies. I will highlight how the distinguishability and mixedness of quantum states influence the interference of multiple single photons – and demonstrate novel schemes for generating multipartite entangled quantum states. I will then address photonic quantum computing, specifically focusing on the building blocks of photonic quantum computers. This includes the generation of resource states essential for photonic quantum computing. I will then shift to photonic quantum networks, covering both their hardware aspects and showcasing quantum-network applications that extend beyond bi-partite quantum communication. Lastly, I will outline how photonic integration facilitates the scalability of these systems and discuss the associated challenges.

Joining the rich photophysics of organic light-emitting materials with the exquisite sensitivity of optical resonances to geometry and refractive index enables a plethora of devices with unusual and exciting properties. Examples from my team include biointegrated microlasers for real time sensing of cellular activity and long-term cell tracking, as well as the development of photonic implants with extreme form factors and wireless power supply that support thousands of individually addressable organic LEDs and thus allow optogenetic targeting of neurons deep in the brain with unprecedented spatial control. Very recently, by driving the interaction between excited states in organic materials and resonances in thin optical cavities into the strong coupling regime, we unlocked new tuning parameters which may play a crucial role in the next generation of TVs and computer displays to achieve even more saturated colour while retaining angle-independent emission characteristics.

A beam of light carrying orbital angular momentum (OAM) is characterized by a helical phase front that winds around the center of the beam. Their unique properties enable applications, e.g. in the field of data transmission, as an additional degree of freedom that could potentially increase the capacity. For free-space optics efficient methods for (de)composing beams based on their OAM exists, but solutions for integrated and compact fiber application without the use of external active optical elements have not been reported. We present a waveguide structure that can serve as a broadband OAM (de)multiplexer for multiple OAM modes simultaneously. The structure design is based on the adiabatic principle used in photonic lanterns for highly efficient conversion of spatially separated single modes into eigenmodes of a few mode fiber. To remove possible degeneracies between modes having the same absolute OAM, an artificial magnetic field is introduced by twisting the structure during the adiabatic evolution. This approach can simplify, stabilize, and miniaturize the creation or decomposition of OAM beams for fiber based applications.

Yttrium aluminium garnet (Y3Al5O12–YAG) has been used in the industry for over 60 years now and lots of new ways for it’s synthesis have been discovered. However, since YAG is an inorganic material - it’s hard to make in a specific shape and size. This hinders it from being further applied in solid-state lasers (as microlasers), in light emitting diode’s (LED’s) (as making microLED’s would be more beneficial) and as light emitting material (phosphor). As currently YAG isn’t being structured on a commercial scale—this article showcases that it can be done with minimal effort and time. In this research, YAG precursors were synthesized, mixed with prepolymer and calcinated to obtain pure YAG. This work aims to show that it’s possible and also relatively easy to synthesize pre-structured YAG, describes it’s properties and also the characteristics of it’s lanthanide-doped versions.

We demonstrate a direct laser writing setup combining 405 nm multi-photon lithography with 4Pi excitation enabled by a spherical reflector (SR) refocussing the transmitted excitation. The SR provides a simplified implementation of the 4Pi geometry, avoiding the need for an additional objective and its interferometrically stabilised excitation beam path, while also recycling the beam power. The reflected beam position is measured by imaging the reflected beam and is controlled by a feedback loop to 10nm in all three dimensions. Using this instrument, the fabrication of sinusoidally modulated nanowires and helicoids with sub-100nm near-isotropic cross-section is demonstrated.

STED-inspired sub-diffractional nanolithography was so far restricted to free radical polymerizations, predominantly of (meth)acrylates. We now expand the STED-inspired toolkit to cationic and oxidative polymerizations, comprising the technologically important classes of epoxides and pi-conjugated polymers. In both cases, we achieved structure sizes below 100 nm using transient-state absorption depletion (TAD) in systems comprising onium salts as initiators and depletable photosensitizers.

Since the development of increasingly compact laser sources emitting short, intense radiation, it has become essential to develop non-linear optical filters for optical limiting. Their role as optical limiters is to protect optical sensor that are exposed beyond their capacity during laser aggression. Two types of process are compared in this study to develop laser protection filters based on a methacrylate polymer matrix with a nonlinear dye as a charge: bulk polymerization and 3D printing. The nonlinear transmission of thermoset polymers is measured on an optical bench at a wavelength of 1064 nm.

We fabricate all-inorganic, high refractive index optics, including metalenses, waveguides, and diffractive optical elements via nanoimprint lithography with TiO2 nanoparticle dispersion inks and report full-wafer fabrication of visible wavelength metalenses with absolute focusing efficiencies greater than 80% (>95% of design efficiency). 3-D metal oxide log-piles are possible via direct NIL using sequential imprint, planarization, imprint cycles followed by removal of the sacrificial planarization layers. 3-D metal log-piles are possible via metallization of imprinted 3-D sacrificial templates. Several examples will be discussed.

The present work evaluates the build accuracy of grayscale laser lithography by employing a series of benchmark artefacts having an active area of up to 1 mm × 1 mm and a structure depth of up to 50 µm with a resolution of 1 µm as models for the production of 2.5D structures with a wide range of representative features in terms of elevation, slope, curvature, aspect ratio and area density. The topography of manufactured samples is determined via laser scanning confocal microscopy and 3D optical microscopy based on white light interferometry, with alignment algorithms developed within MATLAB employed to evaluate local build error over the entire surface. The present work was performed within the Horizon Europe project “Automated Maskless Laser Lithography Platform for First Time Right Mixed Scale Patterning” (OPTIMAL, Grant Agreement No. 101057029).

The smaller the diameter of an endoscope, the greater its potential for minimally invasive surgical treatments. In conventional, flexible (fiber-based) endoscopes with small diameters (<200 µm), imaging is severely limited by the number of fiber cores. Due to this limitation, the image is pixelated. In this work, an engineering approach is used to increase the number of pixels by spectral multiplexing. However, this requires very small color-splitting optical systems at the distal end of the endoscope, i.e., at the body-facing end of the fiber. Such small dispersive optical systems are practically impossible to produce directly on the fiber using conventional techniques. Therefore, the idea is implemented using 3D-printed micro-optics. Preliminary work has shown that multiphoton lithography (fs DLW) is capable of producing imaging and color splitting systems on this size scale. We present the optical design, fabrication and test of a fiber core multiplexing endoscope with a diameter of only 160 µm. Single-shot resolution enhancement is demonstrated by imaging of a USAF test chart and biological samples.

This presentation focuses on examples of devices and components to be used in actual biological and biomedical applications and manufactured in larger quantities. Specifically, we discuss additive manufacturing (full 3D and 2.5D grayscale modes) based on 2PP technology, which allows features of 100nm-150nm and surface roughness of 10-20 nm – sufficient for optical quality components. In addition, the printing volume allows parts of up to 50x50x22 mm3 and thus broader range of possible designs. Here we demonstrate two system examples: (1) high performance (NA=0.6, FOV=200microns, OD = 3.0 mm) hybrid endoscopic microscope objective for 2-photon imaging and diagnostics and (2) image mapping spectrometer for cell signaling in SPIM (Selective Plane Illumination Microscopy) configuration. In both cases we discuss performance of manufactured components and design strategy to optimize both printing time and component/system quality. Presented prototypes demonstrate high level of integration, compact dimensions and design flexibility. Results include high resolution imaging performance (miniature endo-microscopic objective) and snapshot spectral imaging capabilities in cell signaling.

We introduce a compact attachment for microscope objectives that allows for the conversion of conventional fluorescence microscopes into Airy light-sheet microscopes. The attachment includes a one-dimensional Airy beam generator, which comprises a gradient-index collimator and a 3D nano-printed cubic phase-plate, realized through two-photon polymerization 3D nano-printing and a two-step writing process that guarantees an optical-quality surface for the phase plate. The micro-optical unit is affixed to a mechanical holder equipped with micro-stages, thereby facilitating the unit's integration into commercial microscopes. The implementation and imaging performance of this system and its fundamental imaging characteristics are discussed, with findings based on diverse samples.

We present the development and evaluation of metalenses fabricated with the two-photon polymerization-based 3D nanoprinting technology. In our design, we investigated a periodic lattice of multilevel nanopillars, based on the natural ellipsoidal shape of the 3D voxel in the fabrication process. By creating nanopillars with various heights, we can tune the effective refractive index of the metasurface in order to modulate the phase profile of an incoming light beam. We therefore push the fast and flexible two-photon polymerization technique to its limits in terms of dimensions in view of creating high performance metalenses. To demonstrate the optical performance of these metalenses, we also created their refractive and diffractive counterparts with the same fabrication technology to allow for a direct performance comparison. Moreover, we show that these metalenses can be fabricated on the tip of standard telecom single-mode optical fibers for the effective collimation of their output light beam.

Additive manufacturing enables direct prototyping of complex 3D-objects that are difficult and therefore expensive to manufacture using conventional methods. This paper depicts the application of 3D-printed waveguide based pressure sensors in the below knee orthosis. In orthopedic patients, the below-knee orthosis must be adjusted to the lower leg at regular intervals due to anthropometric changes in patient’s body to achieve proper mobility and correct load. Currently, this alteration relies on the patient’s estimation of support load and is only sub-optimal. Hence, the concept of developing an intelligent orthosis with a novel embedded optical system to monitor the exact support load at the neuralgic is proposed. Furthermore, this paper focuses on the implementation of the solid core optical waveguide pair as a pressure sensor.

Additive manufacturing is increasingly used for optical applications, especially for the production of the optical elements. However, larger elements usually require further post-processing steps of the optical surfaces and are not printable as monolithic multi-element systems. Nevertheless, optical systems can still benefit significantly by utilising the design freedom of additive manufacturing for the mounting structures. We designed a fully monolithic and additively manufactured mounting structure that is robust against mechanical and thermal influences from the environment and passively compensates their effects. We present our design approach and prove its feasibility by stressing an imaging lens and evaluating its optical performance.

Multi-photon polymerization is widely recognised as a promising approach for the fabrication of micro- or nano-metric fully 3D structures. The ability to write such structures at high plot rates would open new frontiers in many fields such as health, optical micro-devices, security holograms etc. However, high speed plotting of these structures generally requires complex and expensive optical systems with femtosecond pulsed lasers. We propose a simpler approach based on the use of a continuous wave laser, an imaged spatial light modulator and an ultra-sensitive resist. Light field overlapping in out-of-focus planes is currently a major issue limiting the performance of our fabrication process due to the undesired polymerisation that results. We will present our latest simulation results and show how they are enabling us to develop and apply precompensation techniques to the plot data to fabricate structures with a smaller Z-extent and/or circumvent proximity effects.

3D µ-printing is a versatile technology with huge potential for fabricating high-quality microstructures. However, most structures initially deviate from their designed dimensions due to photo resin properties and/or optical aberrations. We present a deep learning approach to predict and subsequently correct these optical aberrations in high numerical aperture systems, commonly employed in multi-photon lithography. The neural network identifies and calculates corrections for prominent aberrations and allows for easy scaling to arbitrary laser wavelengths. We also demonstrate our first steps of a machine learning approach that allows pre-compensation of microstructures without several (intensive) iterative correction prints.

The use of 3D printed micro-optical components has enabled the miniaturization of various optical systems, including those based on single photon sources. However, in order to enhance their usability and performance, it is crucial to gain insights into the physical effects influencing these systems via computational approaches. As there is no universal numerical method which can be efficiently applied in all cases, combining different techniques becomes essential to reduce modeling and simulation effort. In this work, we investigate the integration of diverse numerical techniques to simulate and analyze optical systems consisting of single photon sources and 3D printed micro-optical components. By leveraging these tools, we primarily focus in evaluating the impact of different far-field spatial distributions and the underlying physical phenomena on the overall performance of a compound micro-optical system via the direct evaluation of a fiber in-coupling efficiency integral expression.

This paper proposes an innovative approach of manufacturing optical fibers using nozzle-mask-aided additive manufacturing. Nozzle-masks ease 3D-printing of optical fibers allowing the manufacturing or drawing of optical fibers of up to 10 μm diameter. These nozzle-masks feature a suction mechanism to prevent clogging of printhead and mask. The extrusion of Polymethyl-methacrylate material through the print-head and nozzle-mask simplifies the rapid prototyping of the optical fibers.

In this work, we implement an exact ray tracing to obtain analytic equations for the caustic surface produced by a convex conic lens, considering a set point sources displayed in a linear array perpendicular to the optical axis placed at arbitrary position along the axis. Additionally, locating the cuspids for all the caustics produced by the set of point sources, we study the image formation through a convex conic lens forming an extended linear object and a preliminary test for this 3D printed prototype lens is presented.

Hollow-core waveguides represent a promising type of on-chip waveguide, enabling strong light-matter interactions for guiding light directly in the medium of interest. Hollow-core waveguides are very established in fiber optics, while they receive much less attention in on-chip photonics. Here, we will show how 3D nanoprinting is used to transfer hollow-core waveguide concepts from fiber optics to on-chip photonics. Two main types of nanoprinted waveguides are discussed, yielding a high-power fraction in the core and lateral access to the core region. We will explain applications of these waveguides in gas- and water-based spectroscopy, nanoparticle tracking analysis and optical fiber interconnection.

Manufacturing of 3D-printed micro optics using two photon lithography (2PL) has been advancing rapidly over the last decade, enabling production of high-performance micro optics. Among many more, 3D-printed miniaturized sensors, imaging optics, OCT systems, spectrometers and optical tweezers appear to be promising for application in the biomedical field. Here, immersion of optical systems into aqueous solutions is required regularly, hence capsulation for protection of the optical system's interior is required. Yet, specific properties of the 2PL fabrication process render capsulation of fabricated optics a delicate task. In this talk, we outline a wholistic design strategy for 3D-printed immersion micro optics. The optical design and the mechanical manufacturing process are addressed, as well as approaches to combine metrology and simulation techniques for accurate assessment and performance optimization of manufactured systems. The feasibility of the proposed concept is experimentally validated. We discuss current limitations and evaluate the future potential of 3D-printed immersion micro optics.

Additive fabrication, in particular direct-laser writing (DLW) combined with two-photon polymerization (TPP), stands out as an innovative tool for creating intricate 3D photonic components. However, the long fabrication time associated with DLW-TPP restricts large-scale implementations. Here, we introduce an adaptative lithography strategy, i.e. flash-TPP, combining one- (OPP) and TPP, while adjusting the resolution of the different sections of the photonic circuit, reducing the printing time by up to 90% compared to TPP-only. Via flash-TPP, we demonstrate the fabrication of polymer-cladded single-mode photonic waveguides and adiabatic splitters, with low 1.3 dB/mm (0.26 dB) propagation (injection) losses and record optical coupling losses of 0.06 dB with very symmetric (3.4 %) splitting ratios for adiabatic couplers. The scalability of output ports here addressed can only be achieved by using the three spatial dimensions, which is challenging in 2D.

Meta-Fibers, which incorporate 3D-printed Metalens into optical fiber facets, are versatile technology with applications in imaging, optical trapping, and electromagnetic wave manipulation. Single-Mode Fiber (SMF) stands out for its defined output, but its limited mode field diameter poses a challenge, often requiring fusion splicing with Multi-Mode Fiber (MMF) or a 3D-printed structure to expand SMF's usable cross-section. However, these methods are complex and may damage the Meta-Fiber. This study introduces an alternative, replacing SMF with Thermally Expanded Core (TEC) fiber, featuring a significantly larger mode field diameter. This approach enables optical trapping and imaging via 3D laser-printed ultra-high numerical aperture metalens into TEC fibers, functioning effectively in diverse environments. The findings expand Meta-Fiber applications, providing an efficient, robust, and scalable solution for optical wavefront manipulation, highlighting the potential of TEC fibers in optics and photonics technology.

Fabrication of glass with complex geometric structures by digital additive manufacturing (3D printing) presents a paradigm shift in glass design and molding processes. Till now, 3D printing glasses have suffered from limited printed glass materials and the low resolution of particle-based or fused glass technologies. Herein, a high-resolution 3D printing of transparent nanoporous glass is presented, by the combination of transparent photo-curable sol-gel printing compositions and vat photopolymerization technology (Digital Light Processing, DLP). Multi-component transparent glass, including binary, ternary, and quaternary oxide nanoporous glass objects with complex shapes, high spatial resolutions, and multi-oxide chemical compositions are fabricated, by DLP printing and subsequent sintering process. We successfully demonstrated the photoluminescence and hydrophobic modification of 3D printed glass objectives. This work extends the scope of 3D printing to transparent nanoporous glasses with complex geometry and facile functionalization, making them available for a wide range of applications.

Among different technologies dealing with additive manufacturing (AM), Laser Induced Forward Transfer (LIFT) is a sustainable and precise manufacturing technology, that shows high potential for industrial application. Here, we propose the use of LIFT to efficiently print metallic patterns and solder materials on PIC chips. This study explores two donor substrates for gold deposition: evaporated gold layers on glass and gold nanoparticle inks, and one donor substrate for solder paste deposition. Parameters like layer thickness, laser scanning speed, donor-receiver gap distance, laser fluence and pulse shape are optimized for quality transfer. Optimization of the LIFT process parameters will enable the reproducible and controllable printing of electrodes for creating an all-printed graphene-based photodetector and the solder paste deposition for assembly applications.

The interest in manned deep space exploration and long-term stays has grown recently for government but also for the private sector. To develop a safe and sustainable infrastructure for future missions, In-Space Manufacturing has to become state of the art. This paper will propose a novel handling mechanism for powder-based material suitable for the microgravitational environment. Ultrasonic levitation is a promising technology for gravitational independent material handling. The fundamental challenge lies in the trapping of powder-based materials. To assist the material deposition process and stabilize the material handling water is used as a carrier material. A multi emitter single axis ultrasonic levitator is employed to levitate Nylon 12 SLS-powder in a fixed state and initiate a laser melting process to bound the powder material. Previous investigations have shown a stable levitation of liquid and solid materials. For the first time it was possible to levitate, and laser melt a SLS material inside an ultrasonic levitation field, enabling a novel handling technology for the microgravitational environment.

Multiphoton Lithography stands as a laser-driven additive manufacturing method, enabling the creation of structures with remarkable resolution, reaching down to the scale of tens of nanometers. Leveraging nonlinear absorption, this technique boasts distinctive capabilities unmatched by other methods. Diverse materials have been successfully employed in its implementation, resulting in the production of various components and devices such as metamaterials, biomedical devices, photocatalytic systems, and mechanical models. The distinguishing feature of Multiphoton Lithography lies in its ability to actualize computer-designed, fully operational 3D devices. This presentation provides a comprehensive overview of microfabrication principles, highlighting recent advancements in materials processing and the functionalization of 3D structures. To conclude, an exploration of future applications and the technology's prospects is presented.

This study addresses the challenges of adding functionality and hybridizing processes in additive manufacturing. It focuses on embedding a gold-coated optical fiber into an INOX structure, aiming to extend this process to optical sensors like fiber Bragg grating arrays. The primary concern is the sensor's resistance to high temperatures during metal deposition, while the second challenge involves the adhesion of filler material to the sensor and structure. The feasibility is assessed through a finite element thermal model and mechanical testing, confirming the process's viability. Successful light transmission through the fiber and tensile tests indicate structural integrity and reduced ductility, warranting further investigation under varying load conditions.

Metal additive manufacturing is currently experiencing strong growth in the industry. Until recently, it remained confined to small dimensions, a consequence of the limits imposed by the technologies used (mainly PBF (Powder Bed Fusion) technology). Today, suppliers offer large PBF machines using numerous lasers to ensure sufficient manufacturing speeds. Furthermore, another large-scale offer is based on the use of DED (Directed Energy Deposition) processes which use an energy source (for example Laser) to melt a deposited filler material to form the volume layer after layer. of the room. IREPA LASER has therefore developed a new technology capable of manufacturing or repairing XXL parts (up to 5 meters in length and weigh up to 5 tonnes). This technology is based on a head for depositing one or more molten metal wires using a high-power laser (10kW). This presentation will be an opportunity to take stock of the evolution of additive manufacturing technologies, and to present the latest results obtained in the field of DED, but also to show that the laser has become essential in manufacturing industries.

Laser Additive Manufacturing (LAM) offers a versatile approach to fabricate composite materials, including heterogeneous and transition materials, characterized by exceptional mechanical properties. In this study, TiN/Ti6Al4V sandwich structural materials were prepared by the Selective Laser Melting (SLM) and Laser Directed Energy Deposition (LDED) processes, each in distinct environments featuring varying nitrogen-to-argon ratios. We conducted a comprehensive investigation, comparing the elemental diffusion, in-situ synthesis, microstructural characteristics, and mechanical properties of TiN/Ti6Al4V sandwich structural materials produced via these two processes. In both SLM and LDED processes, the in-situ synthesis of TiN from titanium and nitrogen atoms yielded robust metallurgical bonds with the Ti6Al4V matrix. The superior performance of TiN/Ti6Al4V sandwich structural materials achieved through LAM results from their laminar structure and the reinforcing effect of internal ceramic particles. Leveraging the combination of soft and hard layers within the sandwich structure, the tensile strength significantly surpasses that of homogeneous materials. Specifically, the sandwich str

It is presently challenging for selective laser melting (SLM) additive manufacturing technique to fabricate metal parts with wall thickness below 100 m. This work investigated the critical conditions of the extremely thin wall thickness of tungsten grids fabricated by SLM. Specifically, the effect of low energy density on the printability of tungsten single tracks and grids via SLM was studied. A thermofluid flow model of the molten pool created in the SLM process was developed based on a computational fluid dynamics approach to illustrate the single-track morphology variation corresponding to printability. The findings demonstrate that at low energy densities, the molten track exhibits four different morphologies: balling, discontinuity and winding, discontinuity but straightness, as well as continuity and straightness. The simulation model, reliably validated by these results, effectively reveals the correlation between printability and the extent of melting in the powder bed. The energy density impacts the heat transfer mechanism and recoil pressure magnitude within the molten pool, thereby determining its flowability to fill voids in the powder bed. Additionally, the grid morp

Optical cavities with nonlinear elements and delayed self-coupling are widely explored candidates for photonic reservoir computing (RC). For time series prediction applications that appear in many real-world problems, energy efficiency, robustness and performance are key indicators. With this contribution I want to clarify the role of internal dynamic coupling and timescales on the performance of a photonic RC system and discuss routes for optimization. By numerically comparing various delay-based RC systems e.g., quantum-dot lasers, spin-VCSEL (vertically emitting semiconductor lasers), and semiconductor amplifiers regarding their performance on different time series prediction tasks, to messages are emphasized: First, a concise understanding of the nonlinear dynamic response (bifurcation structure) of the chosen dynamical system is necessary in order to use its full potential for RC and prevent operation with unsuitable parameters. Second, the input scheme (optical injection, current modulation etc.) crucially changes the outcome as it changes the direction of the perturbation and therewith the nonlinearity. The input can be further utilized to externally add a memory timescale that is needed for the chosen task and thus offers an easy tunability of RC systems.

Programmable photonic circuits manipulate the flow of light on a chip by electrically controlling a set of tunable analog gates connected by optical waveguides. Light is distributed and spatially rerouted to implement various linear functions by interfering signals along different paths. A general-purpose photonic processor can be built by integrating this flexible hardware in a technology stack comprising an electronic monitoring and controlling layer and a software layer for resource control and programming. This processor can leverage the unique properties of photonics in terms of ultra-high bandwidth, high-speed operation, and low power consumption while operating in a complementary and synergistic way with electronic processors. This talk will review the recent advances in the field and it will also delve into the potential application fields for this technology including, communications, 6G systems, interconnections, switching for data centers and computing.

The growing maturity of 3D printing technologies has been reshaping the landscape of numerous fields. Concurrently, the pursuit of large-scale additive manufacturing with enhanced precision and substantial throughput remains a central objective. This study introduces a high-resolution 3D printing technique for quartz glass, achieved through the fusion of transparent Hydrosiloxane (HSQ) printing materials and electron-beam additive manufacturing technology. Introducing a novel concept in 3D lithography, we present the development of an HSQ-based ink that enables the fabrication of large-area 3D photonic crystal structures at a scale of hundred nanometers, utilizing an electron beam driving force distinct from conventional optical technology. This work attempts to find alternative technologies for optical printing and provide new ideas for high-precision 3D printing of silica inorganic materials.

The aim of this study is to explore the potential of using 3d printed Nylone12 to be combined with flexible printed circuit board (FPCB) to make very low cost 2D micromirror. The micromirror comprises an FPCB layer with an embedded actuation coil, a gold-coated silicon layer as the reflective surface, and a structural reinforcement layer of 3D-printed Nylon 12. Previous FPCB micromirrors faced challenges with low resonance frequency or expensive silicon or titanium reinforcement layers, particularly for high-volume production. The micromirror proposed in this paper addresses this by incorporating a batch-produced layer of 3D-printed Nylon 12 powder to enhance stiffness and resonance frequency. The design features a 19mm aperture size, with a horizontal actuation angle of 42±2 degrees optical at 86Hz, 1.6V, sustaining over +80 million cycles of actuation. By integrating FPCB manufacturing, a technique utilized in micromirror design since 2016, with the Nylon 12 reinforcement layer, there is potential for achieving ultra-low-cost micromirror production, particularly for LiDAR applications in industries such as ground robotics.

At Jade University of Applied Sciences in Wilhelmshaven, a Wavelength Division Multiplexer (WDM) for POF is being developed. The design will be based on an Arrayed Waveguide Grating (AWG). Due to large attenuation in polymers, only visible wavelengths (400 nm to 750 nm) are usable. Furthermore, optical polymer fibers (POF) have a large diameter (1 mm) and a high numeric aperture (NA). They usually are multimodal. Multimode transmission leads to reduced coherence, having a direct impact on the required interference in the AWG. Also, the attenuation of the components has to be kept as low as possible. As a result, it is necessary to redesign all components of the AWG. In order to realize this project, simulations are conducted. Different approaches for the calculation and simulation of multimode AWG are investigated. In this publication, a comparison between these approaches will be presented.

Vector beams, especially radial and azimuthal polarization beams, have attracted increasing interest for photonic applications. Traditional free-space approaches to generate these beams rely on bulky elements, leading to a growing demand for more compact, fiber-based solutions that can facilitate monolithic integration. However, existing approaches to generating these beams via optical fibers present several limitations. Here, we introduce an innovative broadband photonic structure designed to generate vector beams at the end of a polarization-maintaining single-mode optical fiber. Employing two-photon lithography, we printed a sub-mm 3D-micro structure with an unprecedented design composed of sequential segments to efficiently transform the fiber’s Gaussian-like beam into radially or azimuthally polarized beams across a wide bandwidth. Our approach could have substantial significance in various fields, including optical communications, optical trapping, microscopy, and material processing.