High-performance receivers for optical interconnects in standard MOS technology

Novel monolithic optical receivers in 0.8 micrometers standard MOS technology with NRZ data rates in excess of 531 Mb/s at 850 nm are introduced. At 638 nm the data rates are above 622 Mb/s. The innovative integrated double photodiode allowing this high speed without any modification in a CMOS process is described and results for their quantum efficiency and for their transient response are presented. Furthermore the improvement of the sensitivity of the photodiodes and the OEICs by an antireflection coating is discussed. The circuit topology of the OEICs is described. A transimpedance input stage with an active MOS feedback resistor is implemented. Analytical calculations for the bandwidth and for the effective transimpedance of the amplifiers as well as measured results are presented. Finally, an OEIC in a 1.0 micrometers CMOS technology with a polysilicon resistor instead of a MOS feedback resistor and implementing a pin photodiode achieves a data rate of 1 Gb/s for 638 nm. The sensitivity of this OEIC is improved by 9 dB m compared to that of a published OEIC.