OPTICAL AND FIBER OPTIC CHEMICAL SENSORS 429 Figure 6.81. Scheme of an image array sensor. (Reprinted from Elosua et al. 2006.) tens of thousands of closely packed individual optical fibers, with each fiber retaining its own isolated optical path, enabling it to transmit a signal from one end to the other. Each individual optical fiber acts as a single pixel, and the assembly of many individual pixels into a fused coherent bundle enables images to be transmitted through the entire length of the bundle, forming a color image that is captured by a charged-coupled device (CCD) camera (Figure 6.81). In the presence of organic vapor mixtures,