Vertical-cavity surface-emitting lasers (VCSELs) are an attractive choice for short-range optical interconnects (OIs) in datacom applications. As the limited bandwidth of VCSEL is the major obstacle to achieve higher data rates in these optical systems, significant effort has been made to develop efficient VCSEL drivers to increase data rate while consuming less power. We review the current state of the art in VCSEL driver design, including choices of semiconductor technology, modulation format, VCSEL configuration, and pre-emphasis techniques, with an emphasis on the challenges associated with VCSEL bandwidth limitations, nonlinearities, and thermal behavior. We illustrate the choices with simulations using a physics-based VCSEL model.

We report a fully differential transimpedance amplifier (TIA) using common base and cascode topology designed with very low input impedance, suitable for integration with photodetectors in optical receiver systems. The on-wafer measurements show a 45 GHz bandwidth and 32 Gbps data transmission with 2.6 pJ/bit energy efficiency. The TIA has a differential gain of 56 dB Ohm and an Input referred noise current density of 30.6 pA/√Hz with a power consumption of 82 mW.

We report the design of a 112 Gb/s radiation-hardened (RH) optical transceiver applicable to intra-satellite optical interconnects. The transceiver chipset comprises a vertical-cavity surface-emitting laser (VCSEL) driver and transimpedance amplifier (TIA) integrated circuits (ICs) with four channels per die, which are adapted for a flip-chip assembly into a mid-board optics (MBO) optical transceiver module. The ICs are designed in the IHP 130 nm SiGe BiCMOS process (SG13RH) leveraging proven robustness in radiation environments and high-speed performance featuring bipolar transistors (HBTs) with f_T/f_MAX values of up to 250/340 GHz. Besides hardening by technology, radiation-hardened-by-design (RHBD) components are used, including enclosed layout transistors (ELTs) and digital logic cells. We report design features of the ICs and the module, and provide performance data from post-layout simulations. We present radiation evaluation data on analog devices and digital cells, which indicate that the transceiver ICs will reliably operate at typical total ionizing dose (TID) levels and single event latch-up thresholds found in geostationary satellites.

In this work, the authors present two transimpedance amplifier (TIA) circuits designed for fibre optical interconnect systems. They compare a common base (CB) topology with a common emitter (CE) shunt–shunt feedback topology in terms of frequency response, power consumption, noise, and input impedance. The two TIAs are designed on a 130 nm indium phosphide double heterojunction bipolar transistor technology from Teledyne Scientific Company (TSC) with an f _t /f _max of 520 GHz/1.15 THz and are measured in the frequency and time domains. They exhibit a transimpedance gain of 42 dBΩ with a 133 GHz bandwidth, the highest bandwidth reported in the literature and power consumption of 32.3 mW for the CB and 25.5 mW for the CE. Eye diagram measurements were conducted up to 64 Gbps and input referred noise density was measured at for the CB and for the CE.

This paper highlights the gain-bandwidth merit of the single stage distributed amplifier (SSDA) and its derivative multiplicative amplifier topologies (i.e. the cascaded SSDA (C-SSDA) and the matrix SSDA (M-SSDA)), for ultra-wideband amplification. Two new monolithic microwave integrated circuit (MMIC) amplifiers are presented: an SSDA MMIC with 7.1dB average gain and 200GHz bandwidth; and the world's first M-SSDA, which has a 12dB average gain and 170GHz bandwidth. Both amplifiers are based on an Indium Phosphide DHBT process with 250nm emitter width. To the authors best knowledge, the SSDA has the widest bandwidth for any single stage amplifier reported to date. Furthermore, the three tier M-SSDA has the highest bandwidth and gain-bandwidth product for any matrix amplifier reported to date.