Fraunhofer-Institut für Photonische Mikrosysteme IPMS

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Now showing 1 - 10 of 11
  • Publication
    Inverse confocal sensor based on a bidirectional OLED display
    ( 2011)
    Grossmann, C.
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    Perske, F.
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    Zwick, S.
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    Riehemann, S.
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    Herold, R.
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    Richter, B.
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    Vogel, U.
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    Notni, G.
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    Tünnermann, A.
    Bidirectional OLED-based microdisplays offer interesting possibilities for new applications. Light emission and detection is combined on one single chip by using OLED on CMOS technology. Such a chip has primarily been developed for optocouplers or photo-electric barriers, but it offers interesting possibilities for other fields. A new optical concept of an inverse confocal sensor based on bidirectional OLED Display will be presented.
  • Publication
    P-176: HYPOLED - high-performance OLED microdisplays for mobile multimedia HMD and projection applications
    ( 2010)
    Scholles, M.
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    Vogel, U.
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    Underwood, I.
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    Notni, G.
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    Zilstorff, C.
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    Meerholz, K.
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    Haas, G.
    The HYPOLED project, partly funded by the European Commission, started in 2008. Its goal is to develop OLED Microdisplays for Mobile Multimedia HMD and Projection Applications. This contribution describes the objectives and present specifications for devices, the personal display and microprojection unit as well as intermediate results.
  • Publication
    HYPOLED - VGA OLED micro-display for HMD and micro-projection
    ( 2009)
    Vogel, U.
    ;
    Underwood, I.
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    Notni, G.
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    Zilstorff, C.
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    Meerholz, K.
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    Haas, G.
    HYPOLED is a collaborative European project that commenced in 2008. It is targeted toward "High-Performance OLED-Microdisplays for Mobile Multimedia HMD and Projection Applications". In this paper, we describe the initial objectives and present draft specifications for devices, the personal display system and micro-projection unit. Initial results are shown and discussed.
  • Publication
    Ultracompact laser projection systems based on two-dimensional resonant microscanning mirrors
    ( 2008)
    Scholles, M.
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    Bräuer, A.
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    Frommhagen, K.
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    Gerwig, C.
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    Lakner, H.
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    Schenk, H.
    ;
    Schwarzenberg, M.
    Recently, there has been substantial progress in the development of ultracompact image projection systems. This has been enabled by the availability of electrically modulated laser sources for all three elementary colors and a 2D resonant microscanning mirror as a micro-opto-electro-mechanical system (MOEMS) device for light deflection. The laser beam formed by collimator optics is directed onto the micro-scanning mirror. Given the movement of the mirror, the laser beam scans the entire image area. By driving the mirror and electrically modulating the intensity of the laser beam in a synchronous manner, a projection of images can be achieved. In this contribution, we present the theoretical background of the projection system as well as the latest achievements in system design. Both monochrome and full-color systems are currently available. The latter uses a separate laser bank as an RGB light source, which is coupled with a projection head. For monochrome red systems, the laser diode can be integrated into the projection head as well, whose volume can be reduced to 15×7×5 mm. All systems have video graphics array (VGA) (640×480 pixels) resolution and operate with 8-bit color depth per pixel and 50 frames per second.
  • Publication
    MEMS compatible illumination and imaging micro-optical systems
    ( 2007)
    Bräuer, A.
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    Dannberg, P.
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    Duparre, J.
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    Höfer, B.
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    Schreiber, P.
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    Scholles, M.
    The development of new MOEMS demands for cooperation between researchers in micromechanics, optoelectronics and microoptics at a very early state. Additionally, microoptical technologies being compatible with structured silicon have to be developed. The microoptical technologies used for two silicon based microsystems are described in the paper. First, a very small scanning laser projector with a volume of less than 2 cm3, which operates with a directly modulated lasers collimated with a microlens, is shown. The laser radiation illuminates a 2D-MEMS scanning mirror. The optical design is optimized for high resolution (VGA). Thermomechanical stability is realized by design and using a structured ceramics motherboard. Secondly, an ultrathin CMOS-camera having an insect inspired imaging system has been realized. It is the first experimental realization of an artificial compound eye. Micro-optical design principles and technology is used. The overall thickness of the imaging system is only 320 µm, the diagonal field of view is 21°, and the f-number is 2.6. The monolithic device consists of an UV-replicated microlens array upon a thin silica substrate with a pinhole array in a metal layer on the back side. The pitch of the pinholes differs from that of the lens array to provide individual viewing angle for each channel. The imaging chip is directly glued to a CMOS sensor with adapted pitch. The whole camera is less than 1mm thick. New packaging methods for these systems are under development.
  • Publication
    Design of miniaturized optoelectronic systems using resonant microscanning mirrors for projection of full-color images
    ( 2006)
    Scholles, M.
    ;
    Bräuer, A.
    ;
    Frommhagen, K.
    ;
    Gerwig, C.
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    Höfer, B.
    ;
    Lakner, H.
    ;
    Schenk, H.
    ;
    Schreiber, P.
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    Schwarzenberg, M.
    Projection systems comprising micromechanical scanning mirrors are a promising approach for information display of any kind. If combined with advanced laser diodes as light sources, ultra-compact projection heads can be realized, as it will be shown in this contribution. Besides the laser, key component of the system is a special MEMS device, a two-dimensional resonant micro scanning mirror. The laser beam formed by collimator optics is directed onto the micro scanning mirror. Then, the reflected beam describes a highly complicated Lissajous figure on the projection screen with flare angles of up to 20 degrees. By driving the mirror and electrically modulating the intensity of the laser beam in a synchronous manner, projection of images can be achieved. Advanced techniques that guarantee improved image quality and allow compensation of artifacts because of relative movement between projection head, screen, and human observer will be described. Based on these principles, several optoelectronic systems have been designed. A monochrome projection head that incorporates the laser diode, optics and the micro minor could be reduced to a volume of 15mm × 7 mm × 5mm. A slightly larger head is attached to a laser unit with red, green, and blue lasers via glass optical fiber for projection of full color images and video streams. All systems have VGA (640 × 480 pixels) resolution. They operate with 8 bit color depth per pixel and 50 frames per second. These key features in combination with the miniaturized size allow their use for a broad range of applications.
  • Publication
    Lanthanide tri-fluorides: A survey of the optical, mechanical and structural properties of thin films with emphasis of their use in the DUV - VUV - spectral range
    ( 2005)
    Uhlig, H.
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    Thielsch, R.
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    Heber, J.
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    Kaiser, N.
    The present candidates for low loss dielectric optical coatings at VUV excimer laser wavelengths are fluorides. Within this group, only one material - namely lanthanum fluoride - is used almost exclusively as high index film material. In search of additional high index film materials for use in VUV we investigated a broader spectrum of lanthanide trifluorides since little is known about their properties and the advantages or disadvantages with regards of their use in DUV- and VUV - optical stacks. Fluorides of lanthanum, neodymium, samarium, gadolinium, ytterbium and also yttrium were evaporated thermally. Precision VUV-measurement were initiated to give an overview of the ranges of UV-transparency up to the absorption edges and to determine the optical indices of these coating materials. Supplementary, also stress measurements, atomic force microscopy and XRD measurements were performed to scrutinize the properties of the films.
  • Publication
    Optical, structural, and mechanical properties of gadolinium trifluoride thin films grown on amorphous substrates
    ( 2005)
    Thielsch, R.
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    Heber, J.
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    Uhlig, H.
    ;
    Kaiser, N.
    Since excimer laser applications extend to deep and vacuum UV wavelengths at 248 nm, 193 nm and 157 nm, renewed research interest has recently arisen on fluoride thin films due to their unrivaled position as wide-bandgap material for the vacuum UV (VUV). Among these materials, only a very limited number can act as the high refractive index component in multiplayer interference stacks. Besides LaF3, gadolinium tri-fluoride is a potential candidate especially for wavelengths at about and below 200nm. We report on the evaluation of the structural properties, the optical properties with emphasis to the DUV - spectral range, and the mechanical properties of GdF3 single layer by means of XRD, GIXR, AFM measurements, spectral photometry and by ex-situ mechanical stress analysis using the laser beam deflection method to measure the substrate deformation. The samples were deposited onto fused silica and silicon substrates by a low-loss evaporation technology in a BAK 640 coating plant applying various deposition conditions.
  • Publication
    VUV optical coatings for the next-generation micro-mechanical mirrors
    ( 2005)
    Yang, M.
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    Gatto, A.
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    Kaiser, N.
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    Schmidt, J.U.
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    Sandner, T.
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    Heber, J.
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    Schenk, H.
    ;
    Lakner, H.
    This paper deals with vacuum UV optical coatings for micro mirrors applications. High reflecting low-stress optical coatings for the next-generation of micro mechanical mirrors have been developed. The optimized metal systems are applicable for the VUV spectral region and can be integrated in the technology of MOEMS, such as spatial light modulators (SLM) and micro scanning mirrors.