A refractometric structure consisting of a side-polished single-mode optical fiber covered with a thin film of hydrogenated amorphous silicon (a-Si:H) has been studied. a-Si:H films have been deposited by plasma-enhanced chemical vapour decomposition of silane. The sensors elements working with zero and first order optical modes of the amorphous silicon waveguide have been demonstrated. A high sensitivity of 5300 nm per unit refractive index has been obtained for the low values of superstrate refractive indices in the range of 1.33-1.38 by using a-Si:H film with a thickness of about 14 nm, i.e. the interaction with TE0 mode of the PWG. Despite of the very low thickness of the a-Si:H film there is no need of any additional layer protecting the structure from the analyzed medium. The mechanical and optical stability of the film and its very good adhesion to fused silica eliminate the possibility of the film damaging and makes the structure reliable in use.
Light beam of weak power (30-300 mW) was deflected (about 5°) passing through the crystal. The beam fans out in the plane determined by the beam direction and c-axis of the crystal. The beam fanning disappeared above 500°C.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.