• Charrier, J.
• Marion, Baillieul
• Němec, P.
• Rinnert, Emmanuel
• Bodiou, L.
• Emeline, Baudet
• L., Adam J.
• Gutierrez-Arroyo, A.
• Michel, K.
• Bureau, B.
• Lemaitre, J.
• Nazabal, V.

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.

Topics

• Deposition
• impedance spectroscopy
• surface
• polymer
• thin film
• simulation
• plasma etching