Takeshi Ihara

Packaging technology for a 10-Gb/s photoreceiver module

We designed a 10-Gb/s photoreceiver module integrating a flip-chip avalanche photodiode (APD), a Si-preamplifier IC, and a slant-ended fiber (SEF). Flip-chip bonding minimizes parasitic reactances in the interconnect between the photodiode and the preamplifier IC. The optical coupling system consists of a slant-ended fiber and a microlens monolithically fabricated on the photodiode. This gives a flat IC-package assembly, which enables stripline interfaces to extract high-speed signals, increases misalignment tolerances, and lowers package height. Tolerances of over /spl plusmn/9 /spl mu/m were obtained in every direction, which matched our theoretical predictions. To attach and hermetically seal the optical coupling, the fiber ferrule was directly laser-welded to the package wall with a double ring structure. The module withstood shock and vibration tests and had a 10-GHz bandwidth and /spl minus/23-dBm minimum photosensitivity at 10 Gb/s. >

InGaP/GaAs HBT-IC chipset for 10-Gb/s optical receiver

We have developed an IC chipset for 10 Gb/s optical transmission systems using high-speed and reliable InGaP/GaAs HBTs. The amplifiers showed over 10 GHz bandwidth and the decision circuit showed a very small decision ambiguity of 6 mV at 10 Gb/s. Using these ICs, we achieved an optical receiver sensitivity of -19.6 dBm, and -36.2 dBm (Pe=10/sup -12/) with an optical preamplifier, for an STM-64 signal. The deviation of receiver sensitivity was within 1 dB over a wide temperature range of 0 to 85/spl deg/C.