We report on a multi-channel wavelength interrogator for the 850 nm wavelength region, constructed by coupling an integrated array of multi-mode, tapered hollow waveguides to a low-cost silicon-based image sensor. The waveguides are clad by omnidirectional Bragg reflectors, such that guided light is radiated in an out-of-plane direction near and at cutoff. Wavelength shifts were extracted using a simple centroid detection algorithm applied to the terminal cutoff point. This concept combines the small size of a Fabry Perot filter with the dispersive property of a diffraction grating. By imaging multiple tapered waveguides onto a single image sensor with each waveguide coupled to a different fiber, simultaneous extraction of wavelength shifts from several wavelength-multiplexed sensors can be achieved in a very compact package. The prototype described provides resolution on the order of 5 pm and can accommodate ~ 20 sensors spaced by 5 nm on each of the 4 fiber input channels. Enhanced capacity and performance are anticipated through future improvements in waveguide materials and the use of more advanced image processing algorithms.
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.