Cascaded Operation of Two 128-Pixel FET-SEED Smart Pixel Arrays

The current trend in device design for free-space optically interconnected systems is towards 2.D arrays of smart pixels, in which each pixel incorporates electronic processing together with optical I/O. The optimal amount of electronic functionality of each smart pixel is a topic of current debate, however, amplification of the detector output signals is common to most proposals. This amplification compensates for the typical optical systems losses of 3 to 15 dB which would otherwise limit the systems to low data rates. Progress has been made in fabrication smart pixel arrays incorporating GaAS FETs and MQW PIN detectors and modulators (FET-SEEDs) and this paper presents an experiment which cascades two 128 pixel arrays of FET-SEED smart pixels.