A hybrid multi-channel receiver featuring fully-differential transimpedance input stages for 25Gbps data rate per channel is presented along with measurement results focusing on the channel-to-channel interference and sensitivity. OMA of -16dBm at a BER of 10−4 is estimated at the photodiode for all channels. Each channel dissipates 330mW of power provided from a single 3.3V supply voltage.

We present a transimpedance amplifier in the optical receiver front-end featuring with an integrated equalizer up to 45 Gbs(-1). It integrates a Schottky-junction varactor diode at the input. The equalization in frequency-domain can be achieved by varying the applied voltage at the Schottky diode. For this end, the proposed circuit was fabricated and measured in both frequency and time-domain. By measuring S-parameters up to 45 GHz and eye-waveforms at 40 and 45 Gbs(-1), the proposed circuit manifests its functionality as the transimpedance amplifier with an integrated analog equalizer.

A fully-differential receiver structure for fiber links is presented, in which the photodiode (PD) is DC-coupled to the transimpedance amplifier (TIA) and biased through the feedback resistors. The biasing voltage is defined by the internal structure of the input stage. Different options are suggested that allow to adjust PD biasing. Multiple architecture variants are proposed, that were implemented in 0.25μm SiGe BiCMOS technology. Initial measurement results are reported, proving the feasibility of the concept. A 25Gbps hybrid receiver designed to comply with a specific standard is also presented, featuring large horizontal eye opening of 800mV, OMA of -15dBm at BER of 10 -6 and power dissipation of 330mW from a single 3.3V power supply.

An optical transmitter incorporating a monolithically integrated laser and a traveling wave electrode in-phase and quadrature modulator is presented. A co-designed SiGe differential driver was co-packaged for highest quality push-pull modulation. With only 0.1-dB coupling loss between the laser and the modulator, and a low modulator switching voltage the transmitter power consumption was 1.1 W, which fits the CFP4 (analog coherent optics) ACO module overall budget of 6 W. Without DSP for precompensation, FEC or equalization, 32 GBd QPSK with 3 V-pp driving voltage and an error vector magnitude of <10% are presented. Operation with an optical signal-to-noise ratio larger than 14 dB is achieved before breaking the hard decision forward error correction threshold (3.8 x 10(-3)).

We present our recent advances in InP-based optical transmitter photonic integrated circuits, developed for compact size, power efficiency and high-speed modulation. The transmitters have low switching voltages of 2 V. Excellent BER performance is achieved up to 64 Gb/s QPSK and 107.4 Gb/s PAM8 operation.

This paper addresses the power reduction concepts of an electro-optical transmitter applicable for future small form factor modules such as CFP4. To satisfy the power restrictions of these standards, equations and detailed explanations of the relevant shares of overall power consumption are given. To improve the overall efficiency, an open-collector driver realized in a SiGe technology with f(T) = 190 GHz and f(max) = 200 GHz is proposed for driving an InP-based IQ MZ-modulator. This approach saves 30 % of the driver power and achieves an EVMrms of 8.7 % for a QPSK signal at 32 GBd. A detailed performance comparison to a structurally identical back terminated driver is presented. Further power reduction is demonstrated with a bias tee configuration for a single modulator. DPSK measurements show a very low power consumption of 290 mW at an EVMrms of 7.5 %. The presented bias tee solution simplifies the assembly without performance compromises. All drivers presented in this paper have differential input/output signals and were designed for a non 50 Ohm output impedance to optimize power consumption and performance.

We show the positive impact of differential driving on the optical QPSK signal performance. For the first time, an EVM of <;6% at 32 GBd QPSK has been achieved for a low power InP-IQM design, enabling small form factor transmitters.

We present for the first time 32 GBd QPSK of an InP-based IQ modulator with monolithically integrated laser and co-packaged SiGe driver. Power consumption is 1.1 W, which is well within the CFP4 module overall budget of 6 W.

A small footprint, low power 105Gb/s PAM-8 TOSA with InP-based/Mach-Zehnder modulator and a customized SiGe differential driver with a modulation power of 3.23pJ/bit is demonstrated. Predistortion is applied to compensate for non-linearities of both devices.

A differential impedance-engineered 32 Gbit/s SiGe driver co-designed with an InP-based MZ-Modulator is demonstrated, showing record low 185 mW power consumption. The small footprint and low power is targeting towards CFP4-sized coherent transceivers. Results on IQ-Modulators will be presented.