High speed BiCMOS linear driver core for segmented InP Mach-Zehnder modulators

A hybrid arrangement for an optical transmitter sub-system comprising a linear driver fabricated in IHP SiGe 0.13 A mu m BiCMOS technology with an InP segmented Mach-Zehnder modulator is described. The proposed scheme, with direct interface to the digital to analog converter, is suitable for coherent high order modulation formats intended for data transmission over optical fiber at a wavelength of 1550 nm. In this paper, a partial prototype, consisting of a single driver core and modulator segment is demonstrated. The driver core features an output differential voltage of 2.5 Vpp, a gain of 9 dB and a 3 dB bandwidth of 32 GHz. Linearity is evaluated through total harmonic distortion measurements. With on-off-keying modulation, electro-optical eye diagram measurements of the single segment demonstrate successful operation up to 40 Gb/s data rate. While exhibiting clear capability for high speed operation, these results serve also to explore the boundaries of the proposed hybrid configuration.