Thomas Mazingue

Optical characterizations of ZnO, SnO 2 , and TiO 2 thin films for butane detection

The optogeometric properties of various sensitive thin films involved in gas sensing applications are investigated by using the m-line technique and atomic force microscopy. Variations of these optical properties are studied under butane and ozone exposure.

Optical and electro-optical properties of pulse laser deposited PLZT thin films

Optical and electro-optical properties of pulse laser deposited PLZT thin films are measured using the m-lines technique. Sample preparation is described. Correlation between the deposition process and optical and electro-optical properties is presented.

Chemical sensors based on optical sensitivity of metal oxide materials deposited on multimode interference couplers

An optical sensor based on MMI structures has been studied. We have used the optical parameters of a new hybrid material deposited by sol-gel method leading to waveguide structures after UV-photoinscription, and of ZnO, sensitive material characterised in previous studies. The variation of optical properties such as the refractive index of the covering sensitive material leads to a modification of waveguiding conditions in the MMI. A gas sensor can be developed by measuring the variation of light intensity at the output of the MMI structure under gas exposure. Simulations have been performed in order to optimise the output light intensity variations to increase sensitivity. We have shown that these structures are more sensitive than Mach-Zehnder interferometers, and that the relation between dimensions and sensitivity of the MMI is not trivial. Computations have to be performed to optimise the structure for given parameters.

Optical sensitivity of thin films to hydrocarbons and ozone

Materials involved in gas sensing applications have been deposited by various methods in thin film form. Variation of the optical properties of the thin films were investigated under butane and ozone exposure using the m-lines technique. Effective index variations down to 10-4 were observed. Concentrations of 100 ppm of butane diluted in the air or in nitrogen were detected.

Optical characterizations of thin films for gas sensors

The opto-geometrical properties of various sensitive thin films involved in gas sensing applications are investigated using m-line technique and Atomic Force Microscopy. Variations of these optical properties under gas exposure are studied.