Figure 1
From: Optofluidic vapor sensing with free-space coupled 2D photonic crystal slabs

(a) Schematic view of a PCS vapor sensor with free-space coupled laser beam. (b) Device top view in x-y plane. (c) Device cross-sectional view in x-z plane. The PCS is coated with OV-101 polymer. PCS configuration: a is the lattice constant, r is the hole radius, tSi and tpoly are the thicknesses of Si and polymer, respectively.