Integrated detection of light propagating in an optical waveguide by a
photodetector array fabricated directly on the waveguide surface is
demonstrated. Laser recrystallization of LPCVD polysilicon patterned with
periodically-spaced anti-reflection stripes is utilized. Lateral p-i-n
photodiode elements formed by ion implantation are characterized by reverse
leakage currents of < 10−11 amp and a typical breakdown
voltage of 50 volts. Optical response is found to be linear over a dynamic
range of greater than 55 dB.