A linear driver for 100-GBd optical transmitters was designed and fabricated in the 90-nm SiGe BiCMOS process. An output-swing-limiting circuit and multitopology peaking method are proposed to extend the bandwidth. The fabricated driver achieved a differential gain of 21 dB with a bandwidth of over 67 GHz and a per-side output 1-dB compression point (Po1dB) of over 11 dBm, corresponding to a differential output swing of over 4.5 $V _{\mathrm {ppd}}$ . The driver was co-packaged with a silicon photonics Mach–Zehnder modulator in a coherent optical subassembly (COSA) module. The module successfully performed a 96-GBd dual-polarization 16QAM optical generation and detection.

An Over 67-GHz Bandwidth 21-dB Gain 4.5-V ppd Linear Modulator Driver for 100-GBd Coherent Optical Transmitter

This letter reports on a 108-GHz bandwidth 0.5- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> InP DHBT analog-multiplexer-driver (AMUX-driver). To the best of the authors’ knowledge, this 2:1 AMUX-driver shows unprecedented 1.9-V ppd 160-GSa/s 160-GBd non-return-to-zero (NRZ) and 2.4-V ppd 100-GSa/s 100-GBd PAM-4 output swings, with very high-quality eye diagrams, without any digital signal processing (DSP) or postprocessing. Up to 3.2 V ppd is obtained in NRZ at 100 GBd. The lumped AMUX-driver also shows record 25.7-dB gain and 2.08-THz gain-bandwidth product with 11.1-dB equalizing capabilities at 86.6 GHz.

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160-GSa/s-and-Beyond 108-GHz-Bandwidth Over-2-Vppd Output-Swing 0.5-μm InP DHBT 2:1 AMUX-Driver for Next-Generation Optical Communications

This letter reports on a 108-GHz bandwidth 0.5-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> InP DHBT analog-multiplexer-driver (AMUX-driver). To the best of the authors’ knowledge, this 2:1 AMUX-driver shows unprecedented 1.9-Vppd 160-GSa/s 160-GBd non-return-to-zero (NRZ) and 2.4-Vppd 100-GSa/s 100-GBd PAM-4 output swings, with very high-quality eye diagrams, without any digital signal processing (DSP) or postprocessing. Up to 3.2 Vppd is obtained in NRZ at 100 GBd. The lumped AMUX-driver also shows record 25.7-dB gain and 2.08-THz gain-bandwidth product with 11.1-dB equalizing capabilities at 86.6 GHz.

160-GSa/s-and-Beyond 108-GHz-Bandwidth Over-2-Vppd Output-Swing 0.5-μm InP DHBT 2:1 AMUX-Driver for Next-Generation Optical Communications

Existing transceiver technology inside data centers will soon reach its limits due to the enormous traffic growth rates driven by new, bandwidth-hungry applications. Efforts to develop the next generation of 800Gbps and 1.6Tbps transceivers for intra-DC optical interconnects have already kicked-off to address the demands in traffic, the exhaustion of the ports at the digital switches and the power consumption limitations inherent to the use of many lower capacity modules. The new generation of optical modules must also provide Terabit capacities at low cost, necessitating the use of high-volume manufacturing processes. TERIPHIC is an EU funded R and D project that aims at developing transceiver modules with up to 1.6 Tbps capacity over 16 lanes in duplex fiber and cost less than 1 € per Gbps for distances up to 2 km, utilizing PAM-4 modulation for 100Gbps per lane and high-volume production compatible transceiver designs. At the component level, TERIPHIC will rely on arrays of high-speed electronics, InP Externally Modulated Lasers (EMLs) and InP photodetectors, and at the integration level it will rely on a polymer photonic platform as a host motherboard, leveraging its flexibility and powerful toolbox. A summary of the progress on the TERIPHIC transceiver modules concept, both at the component level and integration level is presented in this paper.

Enabling low-cost high-volume production compatible terabit transceivers with up to 1.6 Tbps capacity and 100Gbps per lane PAM-4 modulation for intra-data center optical interconnects up to 2km: The TERIPHIC project approach

"Type-II" InP/GaAsSb DHBTs are the first non-GaInAs -based transistors to show oscillation frequencies > 1 THz with the associated benefits of higher breakdown voltages, low power dissipation, and superior linearity and scaling characteristics. Whereas no large-signal characterization of THz transistors is found in the literature, THz InP/GaAsSb DHBTs display attractive 94 GHz load-pull characteristics, and less aggressively scaled devices achieve record saturated output power and output power density per unit emitter area. The physical advantages of Type-II InP/GaAsSb are reviewed here. Beyond impressive analog small/large-signal performance metrics, we report a record mixed-signal performance for a PAM-4 DAC-driver designed and fabricated at III-V Lab in a 0.7-μm InP/GaAsSb DHBT technology implemented on epitaxial layers grown at ETHZ. The DAC-driver offers an unprecedented 5.5-Vppd 90-GBd (180 Gb/s) differential output swing with high eye diagram quality and over 12-dB gain control capability at a 1.1-W power consumption, leading to a record 3.1-GBd E/O modulator driver figure-of-merit (FoM). PAM-4 operation at 112-Gb (224 Gb/s) is also demonstrated with 3.35-Vppd and 0.6-W dissipation, also with a record 2.6-GBb E/O FoM. A 110 GHz bandwidth linear driver with a 16.7 dB gain and 0.85-W consumption was also implemented in the same technology, enabling a 4.1-Vppd output swing at 100 Gb/s both in PAM-4 and NRZ signaling. The all-around outstanding performance of InP/GaAsSb DHBTs makes them attractive for a wide variety of analog and mixed-signal circuit blocks used in modern telecommunication applications.

InP/GaAsSb DHBTs: THz Analog Performance and Record 180-Gb/s 5.5Vppd-Swing PAM-4 DAC-Driver

This paper presents a 86.8-GHz bandwidth 4.9-V ppdiff (peak-to-peak differential) linear electro-optical (E/O) modulator driver fabricated in III-V Lab’s 0.7-µm InP DHBT technology. On-wafer measurements exhibit a differential gain of 15.1 dB at 0.2 GHz and a 4.1-dB peaking gain at 51 GHz. Record bandwidth and maximum peaking-frequency, for a lumped linear driver, are obtained. Very high quality 100-Gb/s NRZ and 50GBd PAM-4 output eye diagrams have been measured. A good measurement and EM-simulation agreement is shown. The InP linear driver power consumption is respectively 0.94 and 1.2 W at 4.1 and 4.9-V ppdiff output swings.

Over 70-GHz 4.9-V ppdiff InP linear driver for next generation coherent optical communications

This paper introduces a novel Equalizer-Driver that combines equalizing and driving functionalities in a single function aimed at increasing the bandwidth and energy efficiency of electro-optical (E/O) transmitters. Implemented in III-V Lab’s 0.7-µm InP DHBT technology, the Equalizer-Driver exhibits in full EM-circuit co-simulation 13 dB of differential gain (S d2d1 ) at 10 MHz and 16 dB of peaking gain at 55 GHz, for a total intrinsic -3 dB-bandwidth over 100 GHz. Transient simulations show it is able to provide an equalized and amplified 3.7-V pp diff linear output signal in PAM4 at 64 GBd, from an input signal filtered by a Bessel filter with a 17-GHz -3 dB-bandwidth. Consuming 1.2 W at its maximum 3.7-V pp diff linear output swing, it is well suited for bandwidth limited optical transmitters at 64 GBd and beyond.

Design of a novel Equalizer-Driver with 3.7 V pp diff linear output swing and 16 dB of peaking gain at 55 GHz for 64 GBd PAM-4 optical communication transmitters

Hersent Romain

Papers

Over 70-GHz 4.9-V ppdiff InP linear driver for next generation coherent optical communications

Design of a novel Equalizer-Driver with 3.7 V pp diff linear output swing and 16 dB of peaking gain at 55 GHz for 64 GBd PAM-4 optical communication transmitters