Integrated evanescent waveguide detector for optical sensing
This paper presents the analysis and development of an evanescent waveguide sensor system, based on a hydrogenated amorphous silicon (a-Si:H) photodiode and a double ion-exchanged waveguide diffused in a borosilicate BK7 glass substrate. The a-Si:H sensor is a p-doped/intrinsic/n-doped diode, with a metal top electrode and an indium tin oxide (ITO) transparent bottom contact. Simulations on the confinement of a monochromatic light in a channel waveguide and its coupling into a thin-film photodetector were performed using COMSOL Multiphysics.