Scanning Micro-Mirrors: From bar-code-scanning to spectroscopy

摘要

Micro Opto Electro Mechanical Systems (MOEMS) reach more and more importance in technical applications. They are smaller than conventional devices, less expensive when fabricated in higher numbers and offer new options concerning reliability and measuring methods. Resonant movable micro-mirrors produced as single crystalline chips with CMOS-compatible technologies provide a broad field of applications. In this paper, we will present different micro-mirrors, which are developed by the Fraunhofer IPMS in Dresden, Germany. They have different layouts and are thus suitable for several applications. Fabricated ID-mirrors with mechanical angles of ± 16° can be used for laser deflection in bar-code-scanners, 2D-mirrors with different sizes and frequencies are suitable for imaging, displaying etc. Furthermore processes to apply diffractive structures on the micro-mirror surface were developed, showing an increased efficiency in the first diffraction order. Thus a micro-spectrometer has been built up, working in a wavelength range of 900 - 2500 nm. Due to the Czerny-Turner set-up, only one fast single InGaAs-photodiode is required.