One of the Phase II milestones for Physical Activation reads: “Change in material optical path length Δ(neffdeff) over active area: 200 nm.” What does this mean?
At normal incidence the wavelength is related to the change in index of refraction times the change is distance. Because proposers may intend approaches which alter one or the other or both of these parameters, the Δ(neffdeff) is meant to provide flexibility in this regard. 200nm refers to the expected wavelength change between the initial reflectance peak wavelength and the shifted reflectance peak wavelength. For example: if your first reflectance peak is at 400 nm, then your shifted peak should be no less than 200 nm away (600 nm or higher).
