In this paper we report the use of a device based on two multilayered a-SiC:H/a-Si:H stacked heterostructures to photodetect and demultiplex optical signals of the visible spectrum. Both heterostructures were optimized for the detection of short and long wavelengths within the visible range. The optoelectronic characterization of the device includes spectral response measurements under reverse bias and using different optical steady state light conditions to soak the device. Results show that the device photocurrent signal measured using appropriate steady state optical bias, allows the separate detection of the input transmitted signals which enables the demultiplexing task. A numerical simulation, gives insight into the transduction mechanism to explain the device wavelength selective behavior.