Waveguide enhanced platform

The absorption-based platforms described previously employed evanescent wave interrogation of a thin sensing layer coated onto a planar waveguide. A sensitivity enhancement strategy for optical absorption-based sensors based on planar, multimode waveguides was developed recently by us18. The objective was to apply this theory to the development of low-cost, robust and potentially mass-producible sensor platforms and the following section outlines the assumptions and predictions of this theoretical model. 

Figure 11. Response of enhanced polymer waveguide platform to gaseous ammonia26.

Burke C.S., Polerecky L., MacCraith B.D., Enhanced polymer waveguide platforms for absorption-based optical chemical sensors, Proc. S.P.I.E., 2002 4876 848-855. Opto-Ireland 2002 Optics and Photonics Technologies and Applications (Galway, Ireland, 2002 ). 

The other platform is dielectrics, for example, silicon dioxide, silicon nitride, silicon oxynitride, tantalum pentoxide, and titanium dioxide. They can be deposited by various methods, such as plasma-enhanced chemical vapor deposition, thermal evaporation, electron-beam evaporation, and sputtering. There are a number of dielectrics with refractive indices ranging from 1.45 to 2.4, facilitating diverse waveguide designs to satisfy different specification. Dielectrics have two other... 

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