Application specific micro scanning mirrors

Use of Micro Scanning Mirror Technology offers several advantages like high frequency scanning and extreme miniaturization of scanning systems. However, cost for technology development in particular for application specific requirements are high and often the development time is too long. At Fraunhofer IPMS a qualified micro scanning mirror technology with high flexibility and several options including integrated position sensors and diffraction gratings was developed1. The process, offered by MEMS Technologies Dresden, is based on the use of BSOI wafers with a 75 μm thick SOI layer. The mechanical elements as well as the driving comb are generated by means of a DRIE etch. In addition to several process options the design space was increased by special design features like e. g. distributed springs to keep mirror flatness extremely high even at high frequencies. With that the requirements of the scanning element of a large variety of applications from 3D TOF measurement2 up to imaging and spectroscopy (grating & Fourier-Transform Spectroscopy) were met. The specific design and process features will be presented by selected applications. This will comprise an array of 14 synchronized micro scanning mirrors with a total aperture of 334 mm² and an optical scan range of 60°. The mirrors’ oscillations are synchronized in frequency and phase by means of photodiodes. The array was developed for a 3D TOF measurements system in architecture. It will further comprise high frequency scanning devices with optical scan range of up to 112° at 16 kHz which was developed for imaging in an endoscope1. Based on its scanner technology IPMS presents the new technological platform VarioS enabling application specific demonstrator samples with customized design at reduced efforts in time and cost