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Tunable optical filters with wide wavelength range based on porous multilayers

Ulrich Mescheder*, Isman Khazi, Andras Kovacs and Alexey Ivanov

Author Affiliations

Institute for Applied Research and Faculty of Medical and Mechanical Engineering, Furtwangen University, Robert-Gerwig-Platz 1, 78120 Furtwangen, Germany

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Nanoscale Research Letters 2014, 9:427  doi:10.1186/1556-276X-9-427

Published: 22 August 2014


A novel concept for micromechanical tunable optical filter (TOF) with porous-silicon-based photonic crystals which provide wavelength tuning of ca. ±20% around a working wavelength at frequencies up to kilohertz is presented. The combination of fast mechanical tilting and pore-filling of the porous silicon multilayer structure increases the tunable range to more than 200 nm or provides fine adjustment of working wavelength of the TOF. Experimental and optical simulation data for the visible and near-infrared wavelength range supporting the approach are shown. TOF are used in spectroscopic applications, e.g., for process analysis.

Tunable optical filter; Porous silicon; Photonic crystal; Dual tunability; Silicon anodization; MEMS; MOEMS; Biosensor