30 Gbit/s PAM4 transmission using an 8-GHz directly modulated multi-section laser.

This paper describes the characterization of a novel directly modulated multi-section laser with a master-slave configuration. Amplitude and phase noise measurements show relative intensity noise values of around -150 dB/Hz and a 3-dB linewidth of around 3 MHz. The laser's suitability for optical access networks, enabled by the chirp reduction from the external injection locking, is shown by demonstrating unamplified 30 Gbit/s C-band transmission over 25 km and 50 km of single mode fiber using PAM4, as well as 30 Gbit/s PAM4 and PAM8 amplified transmission over 75 km.

InP photonic integrated externally injected gain switched optical frequency comb.

We report on an InP photonic integrated circuit for the generation of an externally injected gain switched optical frequency comb. The device is fully characterized and generates a comb with frequency spacing ranging from 6 to 10 GHz, good noise properties that include relative intensity noise of <-130  dB/Hz and linewidth of 1.5 MHz, and a high phase correlation between comb lines.

Multi-wavelength coherent transmission using an optical frequency comb as a local oscillator.

Steadily increasing data rates of optical interfaces require spectrally efficient coherent transmission using higher-order modulation formats in combination with scalable wavelength-division multiplexing (WDM) schemes. At the transmitter, optical frequency combs (OFC) lend themselves to particularly precise multi-wavelength sources for WDM transmission. In this work we demonstrate that these advantages can also be leveraged at the receiver by using an OFC as a highly scalable multi-wavelength local oscillator (LO) for coherent detection.

Flexible wavelength de-multiplexer for elastic optical networking.

We report an injection locked flexible wavelength de-multiplexer (de-mux) that shows 24-h frequency stability of 1 kHz for optical comb-based elastic optical networking applications. We demonstrate 50 GHz, 87.5 GHz equal spacing and 6.

Software reconfigurable highly flexible gain switched optical frequency comb source.

The authors present the performance and noise properties of a software reconfigurable, FSR and wavelength tunable gain switched optical frequency comb source. This source, based on the external injection of a temperature tuned Fabry-Pérot laser diode, offers quasi-continuous wavelength tunability over the C-band (30nm) and FSR tunability ranging from 6 to 14GHz. The results achieved demonstrate the excellent spectral quality of the comb tones (RIN ~-130dB/Hz and low phase noise of 300kHz) and its outstanding stability (with fluctuations of the individual comb tones of less than 0.