Development of an evanescent optical integrated sensor in the mid-infrared for detection of pollution in groundwater or seawater. (2nd October 2017)

• Record Type: Journal Article
• Authors: Baudet, E.; Gutierrez-Arroyo, A.; Baillieul, M.; Charrier, J.; Němec, P.; Bodiou, L.; Lemaitre, J.; Rinnert, E.; Michel, K.; Bureau, B.; Adam, J. L.; Nazabal, V.
• Is Part Of: Advanced device materials. Volume 3:Number 2(2017)
• Page Start: 23
• Page End: 29
• Publication Date: 2017-10-02
• Subjects: Optical sensing and sensors -- mid-infrared -- integrated optics devices -- Chalcogenide glasses -- thin films; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1080/20550308.2017.1338211
• Languages: English
• ISSNs: 2055-0308

Abstract

Abstract: The detection of molecules dissolved in liquid medium can be envisaged by means of an optical integrated sensor operating in middle infrared range. The intended sensor is composed of a cladding and a guiding selenide sputtered layers transparent in middle infrared. Hence, Ge-Sb-Se thin films were selected in view of tailored refractive index contrast, successfully deposited by radio frequency magnetron sputtering and characterized. To maximize the evanescent field at a wavelength of 7.7 µm, a suitable selenide waveguide allowing measuring the optical transmitted power was designed by performing computer simulations based on the effective index method enabling single-mode propagation for a waveguide width between 8 and 12 µm. Selenide sputtered films were micro-patterned using reactive ion etching with inductively coupled plasma process. Finally, optical waveguide surface was functionalized by the deposition of a hydrophobic polymer, which will permit detection of organic molecules in water.