I. Tafur Monroy

Chromatic Dispersion Estimation in Digital Coherent Receivers

Polarization-diverse coherent demodulation allows to compensate large values of accumulated linear distortion by digital signal processing. In particular, in uncompensated links without optical dispersion compensation, the parameter of the residual chromatic dispersion (CD) is vital to set the according digital filtering function. We present different non-data-aided (blind) CD estimation methods for single-carrier transmission under implementation constraint conditions such as bandwidth limitation and sampling rate. The estimation performance for various modulation formats is compared with respect to precision and robustness for a wide range of combined channel impairments.

High bit-rate combined FSK/IM modulated optical signal generation by using GCSR tunable laser sources

We report on the generation of combined FSK/IM modulation format by using GCSR tunable laser sources. FSK modulation, up to 100 Mbit/s, has been achieved by modulating the phase section of a GCSR laser source. We experimentally demonstrate generation of combined FSK/IM modulation at 100Mbit/s and 10 Gbit/s, respectively. We also report on successful FSK label insertion using a SOA-MZI wavelength converter.

Data transmission over polymer optical fibers

Polymer optical fiber (POF) is a promising transmission medium for providing broadband telecommunication services within the customers premises. POF offers several attractive features for data transmission such as broad bandwidth and low cost for in-house, access, and LAN applications. This article presents a review on optical transmission systems using POF and their enabling technologies. A summary is given of experimental data links with record capacity over record transmission distances. Standardization activities in POF technology and transmission are reported. To conclude, we discuss trends for further development and research.

112-Gbit/s × 4-lane duobinary-4-PAM for 400GBase

Novel duobinary-4-PAM signaling is experimentally demonstrated to support a 4-lane low-latency 400GbE client side solution. Direct detection of 112 Gbps transmission over a 5 km single wavelength and polarization fiber link is achieved.

Hybrid optical fibre-wireless links at the 75–110 GHz band supporting 100 Gbps transmission capacities

We present a photonic generation and down-conversion method for realizing a 40Gbps wireless link at the 75–110 GHz band exploiting the recent advances in photonic coherent detection technologies and digital signal processing. Furthermore, we analyze the capacities of hybrid optical fiber-wireless links at the 75–110GHz band, and propose several approaches to overcome the challenges towards 100Gbps wireless capacity.

Optical label switching by using differential phase shift keying and in-band subcarrier multiplexing modulation format

Optical label switching based on combined differential phase shift keying (DPSK) modulation and subcarrier multiplexing is experimentally demonstrated at 10 Gbit/s DPSK encoded payload and 100 Mbit/s amplitude modulated subcarrier-multiplexed labeling. This scheme is spectral efficient and robust to fiber dispersion.

Asynchronous, self-controlled, all-optical label and payload separator using nonlinear polarization rotation in a semiconductor optical amplifier

We demonstrate an all-optical label and payload separator based on nonlinear polarization rotation in a semiconductor optical amplifier (SOA). The proposed scheme uses a packet format composed of a label and payload information signal combined with a control signal by using polarization division multiplexing. The control signal is employed to separate the label from the payload signal by exploiting nonlinear polarization rotation in a SOA. Experimental results show a label from payload suppression factor of 22 dB. This scheme operates asynchronously and does not need external control signal. Clean and wide open eye diagrams are obtained for both the payload and the label signal operating at bit-rates of 10 Gbit/s and 625 Mbit/s, respectively.

Optical switching for dynamic distribution of wireless-over-fiber signals in active optical networks

In this paper, we report on an experimental validation of dynamic distribution of wireless-over-fiber by employing optical switching using semiconductor optical amplifiers; we also provide a channel distribution scheme and a generic topology for such an optical switch. The experiment consists of a four wavelength-division-multiplexed channel system operating on a WiMax frequency band and employing an orthogonal-frequency-division-multiplexing modulation at 625 Mbits/s per channel, transmission of the data over 20 km of optical fiber, and active switching in a 1 × 16 active optical switch. The results show a negligible power penalty on each channel for both the best and the worst case in terms of inter-channel crosstalk. The presented system is highly scalable both in terms of port count and throughput, a desirable feature in highly branched access networks, and is modulation- and frequency-band independent.

Free-Running 1550 nm VCSEL for 10.7 Gb/s Transmission in 99.7 km PON

We present a cooler-less, free-running 1550 nm vertical cavity surface emitting laser (VCSEL) directly modulated at 10.7 Gb/s. We also report on error-free transmission through 40 km of standard single-mode optical fiber, achieved without the use of dispersion-mitigation or mid-span amplification. Inverse-dispersion fiber was utilized to realize a dispersion-matched 99.7 km optical access uplink supporting error-free transmission with 27 dB loss margin. These results indicate the feasibility of implementing cooler-less long-wavelength VCSEL devices in long-reach optical access networks.

Optical phase-modulated radio-over-fiber links with k-means algorithm for digital demodulation of 8PSK subcarrier multiplexed signals

A k-means algorithm for phase recovery of three, 50 Mbaud, 8PSK subcarrier multiplexed signals at 5 GHz for optical phase-modulated radio-over-fiber is proposed and experimentally demonstrated after 40 km of single mode fiber transmission.