Optical Sensing of Ethanol using Porous Silicon Photonic Bandgap Microcavity Structure

Abstract

The present paper reports the feasibility and study of one dimension porous silicon (PS) based photonic bandgap (PBG) microcavity structure for an optical sensing of ethanol. 1D-PSPBG microcavity was fabricated by electrochemical etching process. The reflectance measurement of the 1D-PSPBG microcavity was performed for different concentrations of ethanol. The photonic resonance wavelength of microcavity shows the significant red shift after capillary adsorption because the structure refractive index changes after infiltration of the pores of the microcavity structure. The resonance wavelength shift showed a linear relationship with the different concentrations of ethanol. Also, we observe the ability of reversible sensing by 1D-PSPBG microcavity structures.