A 24-Channel, 300 Gb/s, 8.2 pJ/bit, Full-Duplex Fiber-Coupled Optical Transceiver Module Based on a Single “Holey” CMOS IC

摘要

We report here on the design, fabrication, and high-speed performance of a compact 48-channel optical transceiver module enabled by a key novel component: a “holey” Optochip. A single CMOS transceiver chip with 24 receiver (RX) and 24 laser diode driver circuits, measuring 5.2 mm$,times,$5.8 mm, becomes a holey Optochip with the fabrication of forty-eight through-substrate optical vias (holes): one for each transmitter (TX) and RX channel. Twenty-four channel, 850-nm VCSEL and photodiode arrays are directly flip-chip soldered to the Optochip with their active devices centered on the optical vias such that optical I/O is accessed through the substrate of the CMOS IC. The holey Optochip approach offers numerous advantages: 1) full compatibility with top emitting/detecting 850-nm VCSELs/PDs that are currently produced in high volumes; 2) close integration of the VCSEL/PD devices with their drive electronics for optimized high-speed performance; 3) a small-footprint, chip-scale package that minimizes CMOS die cost while maximizing transceiver packing density; 4) direct coupling to standard 4$,times,$ 12 multimode fiber arrays through a 2-lens optical system; and 5) straightforward scaling to larger 2-D arrays of TX and RX channels.