PP…Cell phones are not listed among the applications for POET but one would think POET could provide sensing needs for cell phones in the future if required.

Interestingly it was innovation that came about in order to reduce the chip set form factor for newer, thinner more efficient cell phones that resulted in the advancements of latest wafer level processing techniques that the POET optical interposer process uses to produce parallel optical circuits. The significant benefits to WLP is that all package fabrication and testing are done on the wafer. As such costs are driven down as wafer size increases and the die shrinks. By embedding multiple die within the same package form factor is further reduced and more optical engines and or higher capacity optical engines can be built per wafer.   

The answer to your second question (if I understand it correctly) is no. POET has indicated that they are building a library of waveguide designs. Dielectric waveguides are designed to meet the filtering needs of each application and mode adjustments for the specific wavelength required for each waveguide connection. So basically the same active components can be used to produce a variety optical engines but what the optical engine is used for is determined by the optical interposer filtering applied in a backend process. Kind of like applying a trim level to a car as a final step at the manufacturer.