UV-VIS-NIR Communication with a-SiC:H Tandem Device

Ultra-violet steady state illumination increases the spectral sensitivity of a pi’npin photodiode. Increased sensitivity in the range of 400-850 nm is experimentally demonstrated. The pi’npin photodiode can be illuminated on both back and front sides. Under front ultra-violet irradiation the gain is high for wavelengths in the 500-850 nm range and strongly quenches the 400-500 nm range. Under back ultra-violet irradiation the gain is high in the 400-500 nm range and strongly quenches for wavelengths in the 500-850 nm range. Using back or front illumination and the relative gain of each wavelength in the 400-850 nm range it is possible to select different wavelength channels. Results show that using different communication channels in the ultra-violet, visible and near infrared ranges the sensor exhibits a multiplexed output of all channels. By selectively illuminating the device with ultra- violet on the back or front sides of the device it enables the demultiplexing retrieval of all channels