Discrete multi-tone (DMT) technology is an attractive modulation technology for short-reach application due to its high
spectral efficiency and simple configuration. In this paper, we first explain the features of DMT technology then discuss
the impact of fiber dispersion and chirp on the frequency responses of the DMT signal and the importance in the
relationship between chirp and the optical transmission band. Next, we explain our experiments of 100-Gb/s DMT
transmission of 10 km in the O-band using directly modulated lasers for low-cost application. In an inter-datacenter
network of more than several tens of kilometers, fiber dispersion mainly limits system performance. We also discuss our
experiment of 100-Gb/s DMT transmission up to 100 km in the C-band without a dispersion compensator by using
vestigial sideband spectrum shaping and nonlinear compensation.
KEYWORDS: Modulation, Laser sintering, Signal to noise ratio, Forward error correction, Transmitters, Numerical simulations, Single mode fibers, Orthogonal frequency division multiplexing, Data conversion, Multiplexers
Discrete multi-tone (DMT) technology is an attractive modulation technique for short reach optical transmission system. One of the main factors that limit system performance is fiber dispersion, which is strongly influenced by the chirp characteristics of transmitters. We investigated the fiber dispersion impairment in a 400GbE (4 × 116.1-Gb/s) DMT system on LAN-WDM grid for reach enhancement up to 40 km through experiments and numerical simulations.
Advanced multi-level modulation is an attractive modulation technique for beyond 100 Gbps short reach optical transmission system. Above all, discrete multi-tone (DMT) technique and pulse amplitude modulation (PAM) technique are the strong candidates.
We compared the 100 Gbps transmission characteristics of DMT and PAM by simulation and experiment. The comparison was done by using same devices and only the digital signal processing was changed. We studied the transmission distance dependence for 0.5 to 40 km and the impact of the frequency responses of the optical devices. Finally we discuss the features of the both modulation techniques.
KEYWORDS: Modulation, Receivers, Single mode fibers, Transmitters, Optical amplifiers, Signal to noise ratio, Data conversion, Digital signal processing, Laser sintering, Signal processing
We experimentally evaluated the transmission performance of discrete multi-tone (DMT) modulation at wavelengths in
the 1300-nm and 1550-nm regions and analyzed the degradation factors. By using their countermeasures to extend
transmission distance, we realized the capacity of 100 Gbps with 2WDM x 50 Gbps over 80 km. To our knowledge, this
work is the highest capacity in 80-km transmission system using direct modulation and direct detection.
These results show that the DMT modulation can be used to realize high capacity transceiver with simple and cost
effective configuration for the bi-directional transmission system like a passive optical network.
KEYWORDS: Modulators, Modulation, Transmitters, Dispersion, Laser sintering, Interferometers, Digital signal processing, Transceivers, Signal to noise ratio, Receivers
Discrete multi-tone (DMT) technology is an attractive modulation technique for short reach optical transmission system.
One of the main factors that limit the performance of the 1.5-m band DMT system is the interplay between the
chromatic dispersion of the transmission fiber and the chirp characteristic of the transmitter.
We experimentally measured and compared the chirp characteristics of various modulator configurations, which are
lithium-niobate Mach-Zehnder modulator, directly modulated laser, and electro-absorption modulator, by the frequency
discriminator method using MZ interferometer. We also measured and compared the transmission characteristics of the
transmitters using above-mentioned modulators and discuss the suitable transmitter configuration for DMT technology.
This paper reports a new approach of applying erbium-doped fiber to an S-band optical amplifier and comparing it with a gain-shifted thulium-doped fluoride fiber amplifier. S-band erbium-doped fiber amplifiers for WDM transmission systems have achieved gains of over 25 dB in wavelengths from 1489 to 1519 nm through the use of silica-based EDFs and ASE suppressing filters. We discuss the feasibility of introducing S-band EDFAs to improve the power conversion efficiencies and gain flatness.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.