title: Birefringent porous silicon membranes for optical sensing.
abstract: In this work anisotropic porous silicon is investigated as a material for optical sensing. Birefringence and sensitivity of the anisotropic porous silicon membranes are thoroughly studied in the framework of Bruggeman model which is extended to incorporate the influence of environment effects, such as silicon oxidation. The membranes were also characterized optically demonstrating sensitivity as high as 1245 nm/RIU at 1500 nm. This experimental value only agrees with the theory when it takes into consideration the effect of silicon oxidation. Furthermore we demonstrate that oxidized porous silicon membranes have optical parameters with long term stability. Finally, we developed a new model to determine the contribution of the main depolarization sources to the overall depolarization process, and how it influences the measured spectra and the resolution of birefringence measurements.
authors.affiliation: UMDO, Materials Science Institute, University of Valencia, Valencia, Spain. jesus.alvarez@uv.es
authors.forename: Jesús
authors.initials: J
authors.lastname: Alvarez
authors.forename: Paolo
authors.initials: P
authors.lastname: Bettotti
authors.forename: Isaac
authors.initials: I
authors.lastname: Suárez
authors.forename: Neeraj
authors.initials: N
authors.lastname: Kumar
authors.forename: Daniel
authors.initials: D
authors.lastname: Hill
authors.forename: Vladimir
authors.initials: V
authors.lastname: Chirvony
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Pavesi
authors.forename: Juan
authors.initials: J
authors.lastname: Martínez-Pastor
mesh_terms: D001718:Birefringence; D004867:Equipment Design; D008567:Membranes, Artificial; D055096:Optical Devices; D016062:Porosity; D012031:Refractometry / Q000295:instrumentation*; D012825:Silicon / Q000737:chemistry*; D014159:Transducers
chemical_list: D008567:Membranes, Artificial; D012825:Silicon