| AVS 55th International Symposium & Exhibition | |
| Thin Film | Wednesday Sessions |
| Session TF-WeM |
| Session: | Chemical Vapor Deposition |
| Presenter: | M. Soltani, INRS-Énergie, Matériaux et Télécommunications, Canada |
| Authors: | M. Soltani, INRS-Énergie, Matériaux et Télécommunications, Canada M. Chaker, INRS-Énergie, Matériaux et Télécommunications, Canada E. Haddad, MPB Communications Inc., Canada R.V. Kruzelecky, MPB Communications Inc., Canada W. Jamroz, MPB Communications Inc., Canada J. Margot, Université de Montréal, Canada P. Laou, Defence R&D Canada-Valcartier S. Paradis, Defence R&D Canada-Valcartier |
| Correspondent: | Click to Email |
The well-known transmitting semiconductor (on) to the reflecting metallic (off) phase transition (SMT) of thermochromic VO2 can be controlled by external parameters such as temperature, pressure, photo-carrier injection, photo-excitation, and an electric field. Also, the transition temperature (about 68 °C) of VO2 can be controlled by metal doping such as W, Ti, Al, Mo, etc. Undoped and doped-VO2 smart coatings are thus excellent materials for various switching applications such as IR uncooled bolometers, smart windows, all-optical, electro-optical and microwave switching devices. Here, we exploit the SMT characteristic of W(1.4 at. %)-doped VO2 active layer in the fabrication of stationary Hadamard shutter arrays. The active layer was synthesized by reactive pulsed laser deposition. The micro-optical active slits were patterned by photolithography followed by plasma etching, while the lift-off process achieved the Au/NiCr electrodes onto the top of the individual micro-slit. This shutter consists of 16 active planar micro-optical slits for which both the infrared transmittance and reflectance switching can be controlled individually at room temperature by an external voltage. This allows performing any desirable on-off switching combinations. Both the electroreflectance and electrotransmittance switching of the individual slits were investigated at 1.55 µm. The transmittance switching was as high as 25 dB, while the reflectance switching was about 6 dB. In addition, the electrotransmittance switching modulation (on/off) was demonstrated at 1.55 µm by switching the individual slits by an external ac signal. This shutter can be used as individually programmable 16 multi-entrance slits (i.e., stationary Hadamard shutter) instead of the traditional single entrance slit of dispersive IR spectrometers. Thus, the role of the Hadamard shutter consists of multiplexing the incoming information into the output detector element arrays using binary coding. As results, enhancement of the signal-to-noise ratio and improvement of both the sensitivities and the resolutions of these spectrometers.