Jun Endo

1.25 Gb/s burst-mode receiver ICs with quick response for PON systems

This paper describes burst-mode receiver ICs with quick response for 1.25-Gb/s optical access networks. In a point-to-multipoint fiber access system, such as a passive optical network (PON) system, the receiver should be able to handle burst-data packets with different amplitudes. In burst-mode transmission, a receiver with a quick response is desired for high efficiency in data transmission. In addition, high sensitivity is also required for such a shared access system. To achieve a quick response and high sensitivity at the same time, a transimpedance amplifier (TIA) with three gain modes has been designed. The use of a hysteresis comparator enables fast gain mode switching. A limiting amplifier with feed-forward auto-offset compensation (AOC) is also used for quick response to burst data. These circuit techniques require no external adjustment. Using these design techniques, optical receiver ICs were fabricated in SiGe-BiCMOS technology. The optical receiver built with the ICs exhibits a settling time of under 20 bits and a sensitivity of -30 dBm with wide dynamic range of over 26 dB using a p-i-n photodiode (PD) for burst-mode optical input at 1.25 Gb/s. These fast-response receiver chips improve the data transmission efficiency. The use of a conventional p-i-n PD and the freedom from external adjustment make it possible to build an inexpensive receiver.

Low-cost 10-gb/s optical receiver module using a novel plastic package and a passive alignment technique

A new low-cost 10-Gb/s optical receiver module constructed using a novel plastic package is proposed. Passive alignment using a glass V-groove substrate and an edge-illuminated refracting-facet photodiode (RFPD) was employed to reduce cost. Instead of a conventional GaAs IC, a Si-bipolar preamplifier IC was mounted on the package to reduce power consumption. High-speed signal lines with a bandwidth of more than 10 GHz were realized using a three-dimensional electromagnetic-field analysis. For the fabricated module, a 3-dB detection bandwidth of 7.7 GHz and a sensitivity of less than -14 dBm at 10 Gb/s were achieved. To confirm the reliability of the fabricated module, a damp-heat test without bias voltage and a temperature-cycling test were performed. The results show that the optical receiver module, if covered with silicone resin, has the ability to withstand humidity and thermal stress.

Isolator-free EA-DFB module with forward error correction

We offer an isolator-free EA-DFB module by employing forward error correction. We analyze the behavior of a laser under optical feedback and the error occurrence mechanism. We obtain error-free operation at the receiver sensitivity of -31 dBm.