This PDF file contains the front matter associated with SPIE Proceedings Volume 10804, including the Title Page, Copyright information, Table of Contents, Author and Conference Committee lists.

The development of additive manufacturing methods has enlarged rapidly in recent years. Thereby the work mainly focuses on the realization of mechanical components. But the additive manufacturing technology offers a high potential in the field of optics as well. Due to new design possibilities, completely new solutions are possible. Thus elements with virtually any geometry can be realized, which is often difficult with conventional fabrication methods. Depending on the material and thus the manufacturing method used, either transparent optics or reflective optics can be developed with the aid of additive manufacturing. Ultimately, the application or the specification decides on the approach. For example, transmissive 3D printed parts exhibit the disadvantage of a significant reduced transmission. Conversely, reflective 3d printed optics often require a greater amount of rework in order to achieve a sufficient optical quality of the surface. Nonetheless there is a high potential in additively manufactured optical components. Here, we compare metal optics (manufactured using a selective laser melting machine) with polymer optics (realized either by stereolithography or by multijet modling). In addition to the basic properties, the post-processing of the 3D printed optics is discussed. This includes, for example, cleaning and polishing of the surface using lasers or a robot based fluidjet process for metallic optics. In the case of the polymer optics a dip-coating process was developed in order to improve the surface quality. Our aim is to integrate the additive manufactured optics into optical systems. Therefore we will present different examples in order to point out new possibilities and new solutions enabled by 3D printing of the parts. In this context, the development of 3D printed reflective and transmissive adaptive optics will be discussed as well. Finally we will give an insight into our current developments. On the one hand the development of a robot based additive manufacturing platform will be discussed. The aim of this platform is to realize optimized 3D printed optical components, which is not possible with standard additive manufacturing machines. On the other hand, the functionalization of 3D printed optics will be discussed. Thereby functionalization can take place on the surface or in the volume of the 3D printed part. Based on the stereolithography method, a monolithic optical component was 3D-printed, showing light emission at different defined wavelengths due to UV excited quantum dots inside the 3D-printed optics.

Laser Direct Writing (including Laser Induced Transfer, Laser Sintering and Laser Patterning) of functional materials has emerged as a reliable, high resolution and versatile fabrication tool for flexible electronics, sensors and optoelectronic components. In this paper we highlight the newest trends of Laser Direct Write manufacturing for the development of a variety of components with electronic, optoelectronic and sensing functionality such RFID antennas and RF transmission lines, biometric and chemical sensors and OTFTs. Moreover, this work reviews the latest developments and the background of Laser Induced Forward Transfer as a 3D additive manufacturing approach for functional devices with applications in organic electronics and in biotechnology. Current technological trends require the precise deposition of highly resolved features, in a direct writing approach which preserve their structural and electronic properties upon transfer, while increasing the number of components that can be integrated in a single device. Laser Induced Forward Transfer meets these requirements. Examples of selected applications, including organic thin-film transistors, metallic interconnects, circuits defects repairing, chemical sensors and biosensors will be presented, highlighting the potential incorporation of lasers into the direct printing of entire devices and components. Moreover, the content of this work extends to the application of Laser printing for the direct transfer of metal nanoparticles on polymeric substrates for the development of plasmonic resonators. It has been shown that the size of the transferred droplets is directly related to the volume of laser-molten material region and can be controlled by the laser beam spot size and film thickness. Controllable transfer of different size droplets was thus demonstrated. The printed NPs have diameters from 150-500 nm, high surface ordering and reproducibility. In metallic or dielectric structures, the nanoparticles in the array act as resonators for the electromagnetic (EM) field, and the interactions between them generate a very rich optical response. In this work, the selective transfer by Laser Induced Backward Transfer and partial embedding of Au nanospheres on PDMS substrates has been demonstrated. The targeted application is the fabrication of a stretchable monochromatic reflector with tunable optical response based on the plasmonic resonance of Au nanospheres ordered in a square lattice. Tensile stress applied on the PDMS will induce pitch size increase and corresponding shift of the resonance.

Light Robotics is one of the newest progenies of the robotics family, bringing together advances in microfabrication and optical manipulation with intelligent control ideas from robotics and Fourier optics. The development of lightcontrollable microrobots capable of performing specific tasks at the microscale requires the ability to sculpt the two protagonists of the story: the light and the microrobots. Complex light sculpting for optical trapping has been in focus for over three decades, and its importance for controlling microscopic objects is well understood. Designing intricate microrobots for the task is a more recent development facilitated by state-of-the-art microfabrication techniques, and particularly by two-photon polymerization. The full 3D design freedom offered by two-photon polymerization opens the door for imagination, while at the same time bringing the responsibility of rationally designing microrobots tailored to specific tasks. In addition to shape and topology features, the surface chemistry of the microrobots can also help steer them towards specific applications. This paper will discuss strategies for the design and fabrication of light-controllable microrobots as a toolbox for biomedical applications.

In recent years the integration of graphene on nanoscale waveguides has attracted much attention as it allows using wellestablished CMOS technology for constructing next-generation photonic integrated circuits. However, important challenges need to be overcome regarding the fabrication and patterning of graphene-covered waveguide devices. In addition, a more in-depth investigation of the fundamental optical properties of graphene-covered waveguides, and in particular their nonlinear optical characteristics, is required. The latter are promising for, amongst others, generating spectrally broadband light useful for a wide range of application domains including telecommunications and sensing. In this paper we present a novel approach for patterning graphene on top of waveguides, and provide new insights in the nonlinear optical properties of graphene-covered waveguides. The patterning approach that we developed is chemicalsfree and based on laser ablation and plasma etching, removing the graphene top layer without damaging the underlying material. Regarding graphene's nonlinear optical properties, we focus on the nonlinear-refraction process of self-phase modulation causing spectral broadening of laser pulses in graphene-covered waveguides. We show that the underlying physics is not based on refraction induced by graphene's conventional third-order susceptibility, but instead on a much more complex phenomenon that we call saturable photoexcited carrier refraction.

In this paper, we describe and analyze the distortions that occur in the production of Fourier holograms by the projection method using SLM and in a printed way. Mathematical simulation of projection method allowed to take into account the influence of diffraction on apertures on the structure of the obtained hologram. It is shown that the final structure after recording and the simulation result are similar. When analyzing the printed method of obtaining holograms, we took into account the distortions that arise due to incorrect consideration of the resolution of the printer and the wrong choice of the size of the printed hologram Numerical results of simulation and holograms reconstruction are obtained.

Quantum dots have been considerred to be suitable candidates for down-shifting applications. The integration of quantum dots with Si photodetector provide low cost method to extend the reponse in the UV region. However, the lack of suitable processing technique reduce the reposne in visible region. In this work, we firstly report the integration of in-situ fabricated perovskite quantum dots embedded composite films (PQDCF) as down-shifting materials for enhancing the ultraviolet (UV) response of silicon (Si) photodetectors toward broadband and solar-blind light detection. External quantum efficiency measurements show that the UV response of PQDCF coated Si photodiodes greatly improved from near 0% to at most of 50.6±0.5% @ 290 nm. As compared to the calculated maximum value of 87%, the light coupling efficiency of the integrated device is determined to be 80%@395 nm, suggesting an efficient down-shifting process. Furthermore, PQDCF was also successfully adapted for electron multiplying charge coupled device (EMCCD) based image sensor. The PQDCF coated EMCCD shows linear response with high-resolution imaging under illumination at 360 nm, 620 nm and 960 nm, implying the ability of broadband light detection in the UV, visible (VIS) and near infrared (NIR) region. Furthermore, a solar-blind UV detection was demonstrated by integrating a solar-blind UV filter with PQDCF coated EMCCD. In all, the use of PQDCF as luminescent down-shifting materials provides an effective and low-cost way to improve the UV response of Si photodetectors.

3D printing has changed the way we make things. However, high-resolution 3D printing like microstereolithography is mainly done using polymeric (mostly acrylic or epoxy based) resins. High purity glasses, like fused silica glass, are the materials of choice whenever materials with a high chemical and thermal resistance combined with an outstanding optical transparency are required. However, fused silica glass is notoriously difficult to structure on the microscale requiring hazardous etching processes. We have therefore developed novel silica nanocomposites which can be 3D printed using stereolithography and microstereolithography. The resulting polymeric nanocomposites are turned into fused silica glass via thermal debinding and sintering. Using microstereolithography features with tens of microns resolution and surfaces with a roughness of a few nanometers can be printed. We further demonstrate that these nanocomposites can be used as a negative photoresist in lithography and grayscale lithography applications.

We developed high-quality single fluoride crystals by Czochralski technique. This activity covers different applications such as IR and visible laser, RX detection Metrologic applications and solid state crycooler. The active parts of these devices are insulator hosts containing fluorine doped with trivalent rare earths to develop solid state laser in the UV, visible and near infrared wavelength region. We have investigated the spectroscopic properties and energy transfer mechanisms to tune high-efficiency IR tunable lasers (about 300 nm) in CW and pulsed operation regime. By the same materials we have investigated laser emission in the visible region by fluoride crystal doped with Pr3+ and Dy3+ and showed the potential applications for optical atomic clock. It has been showed for the first time the yellow CW laser emission by fluoride crystals. Moreover, we have investigated the cooling effect on insulator materials by optical pumping. In particular we evaluated the critical cooling parameters:  and EQE (ext) of different crystals. We studied LiYF4 crystals doped with different Yb3+ doping levels. Moreover, it has been estimated the cooling power for possible optical crycooler applications. On the same materials (LiYF4) we proposed a new possible scheme to increase the cooling efficiency. This has been possible co-doping the samples by Yb3+ and Tm3+. This approach has allowed to obtain the lowest temperature (87 K) and the highest T=190 K.

Microfluidic systems have gained much interest in the past decade as they tremendously reduce sample volume requirements for investigating different phenomena and for various medical, pharmaceutical and defense applications. Rapid heat transfer and efficient diffusive material transport are among the benefits of miniaturization. These have been achieved so far by tediously designing and fabricating application-specific microfluidic chambers or by employing microdevices that can be difficult to integrate in microfluidic systems. In this work, we present the fabrication and functionalization via two-photon polymerization and physical vapor deposition of microstructures that serve as heat sources in microfluidic devices upon laser illumination. In contrast to other existing methods that rely on photo-thermal effects, our microtools are amenable to optical manipulation and can be actuated in specific locations where heat generation is desired. Heating effects manifest in the presence of a temperature gradient, induced fluid flow and the formation of microbubbles.

The different techniques and approaches have been used in order to study the optical materials and to develop the novel macro- and nanostructures based on these materials. Among them the priority can be done to the laser oriented technique and to the nanotechnology approach. In the current paper the materials surface structuration are shown by use of the CO₂-laser under the varied electric field of 100-600 V × cm^-1. At this condition the carbon nanotubes have been deposited in the vertical position at the materials surfaces and organized the covalent bonding between carbon atoms and matrix materials atoms. The comparative results about change of the spectral, mechanical and wetting phenomena are presented for such inorganic materials: MgF₂, BaF₂, CaF₂, LiF, Si, Ge, ZnSe, Cu, Al, etc. Mechanisms responsible both for the spectral characteristics change and the mechanical hardness as well as for the wetting angle increase are discussed. Analytical and quantum chemical calculation have been made to support the experimental results. Based on the new obtained results, some emphasis is given on the change of the polymer materials surface relief, when these organics are doped with the effective nano-objects (fullerenes and/or nanotubes) with the varied concentration. The structured inorganic and organic materials can extend the area of the application not only in the general optoelectronics, but in the solar energy direction and in the biomedicine as well.

For high temperature sensing applications, metal/oxide/semiconductor (MOS) devices based on SiC show great promise, particularly above 200 °C, which represents an upper bound for MOS devices based on silicon (Si) semiconductor. This paper presents an investigation of a smart system based on silicon carbide technology used as hydrogen sensor at high temperature. The (Pd/SiO₂/SiC) sensor was fabricated using microelectronics technology. The semiconductor used was 4H-SiC wafer, with two epitaxial layers: a buffer layer with a thickness of 0.5 μm and an active doped layer (N_D=2.07x10¹⁶ cm^-3) with a thickness of 8 μm. The silicon oxide (SiO₂) layer, with 30 nm thickness was thermally grown by dry oxidation. The electrode of the capacitor was a catalytic metal, obtained by D.C. sputtering deposition of a palladium (Pd) thin film with 50 nm thickness. A chip structure with 400 μm diameter was obtained by photolithographic process.

The experiments were aimed at the electrical behavior of the M/O/SiC device at gas concentrations from 0 ppm to 2000 ppm H₂ in argon (Ar). The C-V characteristics of the H₂ sensor shift to smaller voltages with increasing gas concentration. The bias voltage shift is caused by hydrogen adsorption in metal-oxide and oxide-semiconductor interfaces. The flat band voltage has an important decrease when H₂ concentration increases and reaches a -4.05 V shift at 2000 ppm H2 in Ar. These results show that the Pd/SiO₂/SiC sensors are suitable for detection of small H₂ concentrations (10-200 ppm H₂), particularly for detection of H₂ leakages.