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.

High speed InP-based travelling wave electrode (TWE) Mach-Zehnder modulators are presented and their integration capabilities to fabricate next generations of compact and high capacity transmitter components by utilizing so-called “monolithic-on-hybrid” integration approaches are emphasized.

The state-of-the art of medium and large scale InP-based Mach-Zehnder modulator PIC development is reported with regard to commercial fabrication of advanced transmitter components.

An InP-based 90° hybrid OEIC with integrated pin-photodiodes is presented. It operates unaffected in the temperature range of 15°-35° C, offering low PDL <;1 dB, and stable performance in the wavelengths of 1530 nm to 1565 nm.

We demonstrate excellent 40 Gbit/s operation of a packaged InP Mach-Zehnder-Modulator with a low rms jitter of 730 fs. A modulator with 63 GHz on-chip bandwidth is shown as a step towards 80 Gbit/s transmission.

We report on the design, fabrication and experimental results of an InP based travelling wave electrode Mach-Zehnder modulator integrated with a vertical taper for spot size conversion. The device displays high alignment tolerances and an improved insertion loss. The 3 dBe bandwidth of the modulator amounts to 45 GHz.