<p>An active optical shutter for infrared light (3-5 μm) has been designed, exploiting the phase transition in thermochromic vanadium dioxide (VO<sub>2</sub>). A spin coating processing route for VO<sub>2</sub> films has been adapted to manufacture reproducible depositions onto sapphire (Al<sub>2</sub>O<sub>3</sub>) substrates. The VO<sub>2</sub> films have been characterized by X-ray powder diffraction (XRPD) and infrared spectroscopy (FTIR), showing 55 % transmittance in the open mode and 0.1 % in the closed mode.</p><p>The VO<sub>2</sub> film temperature determines the operating mode of the shutter, and a resistive circuit of gold was deposited on top of the film for heating purposes. Switching times from the open to the closed mode down to 15 ms have been measured.</p><p>This work is a part of a comprehensive project at the Swedish Defence Research Agency (FOI), aiming to improve active components for protection against lasers. The shutter within this work is at this stage an early prototype, and needs further development and complementary systems such as a control unit to be implemented in an optical system.</p>
| Identifer | oai:union.ndltd.org:UPSALLA/oai:DiVA.org:liu-6458 |
| Date | January 2006 |
| Creators | Johansson, Daniel |
| Publisher | Linköping University, The Department of Physics, Chemistry and Biology, Institutionen för fysik, kemi och biologi |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, text |
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