69 Gb/s DMT direct modulation of a Heterogeneously Integrated InP-on-Si DFB Laser

A heterogeneously integrated InP-on-Si DFB laser, with direct modulation bandwidth of 21GHz has been used for the generation of a 69Gb/s discrete multi-tone signal. Transmission at 56Gb/s over 5 km SSMF is demonstrated as well

High speed direct modulation of a heterogeneously integrated InP/SOI DFB laser

An integrated laser source to a silicon photonics circuit is an important requirement for optical interconnects. We present direct modulation of a heterogeneously integrated distributed feedback laser on and coupled to a silicon waveguide. We demonstrate a 28 Gb/s pseudo-random bit sequence non-return-to-zero data transmission over 2 km non-zero dispersion shifted fiber with a 1-dB power penalty. Additionally, we show 40-Gb/s duobinary modulation generated using the bandwidth limitation of the laser for both back-to-back and fiber transmission configurations. Furthermore, we investigate the device performance for the pulse amplitude modulation (PAM-4) at 20 GBd for high-speed short-reach applications

Design of Optical Access Systems using Computer Modeling

Abstract — We present numerical techniques that allow efficient modeling of the transport of broadband services over fiber-optic links in access networks using various technologies. Application examples of Hybrid Fiber Coax (HFC), Radio-over-Fiber (RoF) systems and 10-Gb/s Ethernet transport over multimode fiber are provided to demonstrate the value of simulation during the R&D and deployment phases of product introduction

Equalization Enhanced Phase Noise in Coherent Optical Systems with Digital Pre- and Post-Processing

We present an extensive study of equalization enhanced phase noise (EEPN) in coherent optical system for all practical electronic dispersion compensation configurations. It is shown that there are only eight practicable all-electronic impairment mitigation configurations. The non-linear and time variant analysis reveals that the existence and the cause of EEPN depend on the digital signal processing (DSP) schemes. There are three schemes that in principle do not cause EEPN. Analysis further reveals the statistical equivalence of the remaining five system configurations resulting in EEPN. In three of them, EEPN is due to phase noise of the transmitting laser, while in the remaining two, EEPN is caused by the local oscillator. We provide a simple look-up table for the system designer to make an informative decision regarding practicable configuration choice and design

Effective linewidth of semiconductor lasers for coherent optical data links

We discuss the implications of using monolithically integrated semiconductor lasers in high capacity optical coherent links suitable for metro applications, where the integration capabilities of semiconductor lasers make them an attractive candidate to reduce transceiver cost. By investigating semiconductor laser frequency noise profiles we show that carrier induced frequency noise plays an important role in system performance. We point out that, when such lasers are employed, the commonly used laser linewidth fails to estimate systemperformance, and we propose an alternative figure of merit that we name "Effective Linewidth". We derive this figure of merit analytically, explore it by numerical simulations and experimentally validate our results by transmitting a 28 Gbaud DP-16QAM over an optical link. Our investigations cover the use of semiconductor lasers both in the transmitter side and as a local oscillator at the receiver. The obtained results show that our proposed "effective linewidth" is easy to measure and accounts for frequency noise more accurately, and hence the penalties associated to phase noise in the received signal

Lattice pilot aided DMT transmission for optical interconnects achieving 5.82-bits/Hz per lane

We experimentally demonstrate 276-Gbps net rate 128QAM-DMT transmission at soft-FEC limit in an IM/DD system with a single C-band packaged EML, a DAC and a photo-detector, proposing a lattice pilot algorithm for channel equalization with only 1% overhead reaching spectral efficiency of 5.82-bits/Hz per lane

100 Gbaud PAM4 link without EDFA and post-equalization for optical interconnects

We show 100 Gbaud PAM4 400 meters link with performance below the 7% HD-FEC limit of 5x10-3 without optical amplification and post-equalization. We also show 300 Gbps PAM8 line rate transmission over 400 meters of SSMF in C-band