from March 27 to March 28, 2007 in Paris/France

Hall 1bb Stand 118

Fraunhofer IPMS carries out customer specific developments in the field of microelectronic and microsystem technology in Dresden. The aim is to act as a business partner in helping to transfer innovative ideas into new products. The Fraunhofer IPMS is prepared for pilot production of modern CMOS compatible MEMS technology products in its own clean room facilities. About 200 scientists work with modern equipment to provide customer specific solutions in the field of circuit design, sensors and sensor systems, micromechanical actuators and actuator systems, lightmodulating microsystems, image processing and image transmission and organic electronics. At the SSI 2007 in Paris, Fraunhofer IPMS will present:

1. Full Color Laser Projector

Fraunhofer IPMS shows a full color laser projection system based on its own two dimensional micro scanning mirror. The system contains an ultra compact projection head and a separate laser and signal processing unit. It allows the projection of arbitrary images and video sequences with a geometrical resolution of 640 x 480 pixels, 256 brightness levels per pixel and elementary color, and 50 hertz frame rate. The projection modules developed by Fraunhofer IPMS overcome limitations of conventional projection systems – like rather large components for light deflection and high power light sources that consume lots of electrical power and radiate most of it thermally – by deploying the micro scanning mirror as key element for image generation and lasers as light sources. The patented micro scanning mirror of Fraunhofer IPMS is an ideal base for the development of compact projection heads. It distinguishes itself by high mechanical robustness and ease of both electrical control and optical coupling of the laser beam. Besides the expertise of Fraunhofer IPMS in design and manufacturing of this mirror, the competence of the institute for development of all necessary hardware and software for the projection system was used to build the overall projection system. Important markets for the projection system are certainly Infotainment in mobile devices (PDS, Laptop, …), Automotive industry (driver assistance, Head-Up Display, Infotainment), and Medicine electronics (acquisition of biometrical data, positioning aid for X-Ray diagnosis and treatment). However, they can also be manifold used in Production technology (projection of reference points for drilling etc., pattern generator for tailoring of steel plates), and Metrology (structured lighting).

2. OLED on silicon integration

So far there is no technology capable in combining monolithic integration of highly efficient and stable light sources into standard silicon CMOS. For the first time OLED technology allows both large-area deposition and micro-patterning of light emitters on top of uppermost metal layers of CMOS chips. Therefore CMOS active area space below the OLED electrode is available for additional circuitry in a System-on-Chip setup, including OLED driving (as minor part of it). OLED processing is performed by post-processing at wafer-level. return of the wafers into CMOS processes is not required. Major applications are expected for microdisplays and optoelectronics (organic microsystems).

Applications microdisplays:

• electronic viewfinder
• projection
• head mounted displays (mobile communication, consumer electronic, …)
• optical inspection
• patterned illumination

Applications optoelectronics:

• light barriers (reflection type)
• opto-couplers
• optical sensors (chemical, medical → fluorescence, photoplethysmography,…)
• communication (chip-to-chip, board-to-board, chip-to board)

Additonally the OLED fabrication technology offers firstly the possibility to integrate highly efficient light source into silicon to establish a new class of organic based microsystems. The Fraunhofer IPMS offers developments in this novel application area. At the SSI show 2007 the Fraunhofer IPMS is going to present highly efficient OLEDs integrated into silicon backplanes in the form of rows or arrays for opto electronic and microdisplay applications.

3. Image recognition through turbulent media by MEMS micromirror-based Adaptive Optics

The technology of Adaptive Optics (AO) for image recognition through turbulent media originally evolved from astronomy for more than 30 years and has been employed at ground-based telescopes in order to compensate for atmospheric turbulences for an enhanced optical imaging. Besides the actual image recording unit an AO system essentially comprises a wavefront sensor and a wavefront corrector for measurement and compensation of the occuring optical wavefront aberration across the entrance pupil aiming at a pure diffraction-limited imaging in the ideal case. The key component is formed by the actual corrector device, where mostly a deformable mirror is used for a dynamic generation of appropriate surface profiles in order to cancel the optical path differences.

So far, existing systems mainly from astronomy are comparatively heavy, bulky and expansive, which actually is the main impediment for a wider dissimination and commercial exploitation of AO technologies in other application areas. However, nowadays the methods of micromachining and semiconductor fabrication have opened up new perspectives especially in terms of large-scale intergration of micromechanical MEMS mirror arrays on top of integrated address circuits enabling an unprecedented spatial resolution and precision together with a significant device miniaturization and a cost-effective fabrication.The Fraunhofer IPMS therefore has developed a fine segmented  240 x 200 micro mirror array for high-resolution optical wavefront control including also the complete driver hardware and software. Furthermore, for presentation purposes as well as for a more quantitative analysis a compact and flexible AO demonstration system has been implemented, where the obtainable imaging enhancement for various static or dynamic wavefront distortions can be impressively demonstrated.

Possible applications are image and object recognition in machine vision, wavefront correction for optical imaging enhancement e.g. in ophthalmology, microscopy, and astronomy as well as spatial and temporal laser beam and laser pulse shaping. For those purposes MEMS micromirrors offer further advantages in terms of fast mechanical response times, high spectral bandwidth from IR to DUV, and polarization insensitivity.