Research And Design Of High-speed And High-sensitivity CMOS Optical Receiver For Optical Communication

OEIC is a good way to achieve high speed and large volumes in optical communications. Compared to the hybrid-integrated photo-receiver, the monolithic CMOS optoelectronic integrated receiver not only reduces the cost of receiver greatly, but also eliminates the parasitic elements caused by packaging and interlinkage between different modules, and electromagnetic interference and noise of extra environment effectively. This technology also has advantages of reducing chip area, achieving higher yield and higher reliability. To promote the commercialization of FTTH (Fiber-to-the-home) for the pursuit of life comfort, monolithic, optoelectronic integrated receivers based on standard CMOS technologies have been researched much recently. In order to overcome the bottleneck of the CMOS receiver, the following research and experiments are presented.A P+/DNwell/Psub double photodetector was designed and fabricated in chartered 0.35μm CMOS process. The photodetector achieves a 301MHz bandwidth and a 16.3mA/W responsivity for an 850nm input optical signal.A MSM(metal-semiconductor-metal) photodetector compatible with standard CMOS process was proposed, which was composed of two back-to back Schottky diode. A MSM photodetector composed of metal1 and Nwell was implemented in chartered 0.35μm process. The MSM photodetector achieves a 919MHz bandwidth and a 0.21A/W responsivity.A differential common source receiver with a P+/DNwell-N+/DPwell differential photodetector was fabricated in chartered 0.35μm CMOS process. 1.5Gb/s optical data are successfully transmitted at the incident optical power of -11dBm.A RGC(regulated cascode) receiver with P+/DNwell/Psup double photodetector was implemented in standard CMOS technology. RGC TIA(transimpedance amplifier) provides low input resistance as well as large bandwidth. A 1Gb/s bitrate is achieved and the bandwidth is 821MHz.A monolithically standard CMOS optical receiver with a MSM photodetector is presented in this paper. An active-feedback TIA with negative Miller capacitance is used to increase the bandwidth of the receiver. The MSM photodetector with high responsivity provides higher sensitivity for the optical receiver. The optical receiver implemented in chartered 0.35μm process achieves a 1.7 GHz bandwidth due to the low capacitance of the MSM photodetector. 2 Gb/s optical data are successfully transmitted at an optical power of -15 dBm.