Martin Bouda

Compact high-power wavelength selectable lasers for WDM applications

Wavelength selectable lasers with record +1O dBm fiber coupled output power and uniform characteristics have been realized by integration of eight-channel distributed feedback laser arrays with low-loss multi-mode interference combiners and optical amplifiers with a length of only 2 mm.

Cost-Effective Optical Access Upgrades using Wavelength Shared Hybrid Passive Optical Network Architecture

We propose and demonstrate a novel wavelength shared hybrid passive optical network (WS-HPON) architecture for symmetric gigabit PON capacity upgrades with installed equipment re-use, to bridge the technology gap between gigabit- and WDM-PON systems cost- effectively.

Interplay between PDL and nonlinear effects in coherent polarization multiplexed systems.

We analyzed the mechanism of the interplay between PDL and fiber nonlinear effects and showed that PDL can generate large data-dependent optical peak power variations that can worsen nonlinear tolerance and cause additional 1.4dB Q-penalty.

Extended-Reach Wavelength-Shared Hybrid PON

Experiments using commercial GPON equipment and optical modules demonstrate feasibility of extending reach of a GPON system using colorless ONTs to 60 km, providing 128 subscribers with 40 Gbps shared downstream capacity over a single backhaul fiber.

Reachability matrix and directed search-based optical path computation for large optical networks

We demonstrate for the first time computation of both single and disjoint regenerated paths using all-optical reachability matrix and hierarchical guided search, scaling to optical networks with thousands of nodes.

Accurate prediction of quality of transmission based on a dynamically configurable optical impairment model

We have proposed a dynamically configurable and fast optical impairment model for the abstraction of the optical physical layer, enabling new capabilities such as indirect estimation of physical operating parameters in multivendor networks based on pre-FEC BER information and machine learning. BER is commonly reported by deployed coherent transponders; therefore, this scheme does not increase hardware cost. The estimated parameters can subsequently be used to predict optical signal quality at the receiver of not-already-established optical connections more accurately than possible based on the limited amount of information available at the time of offline system design. The higher accuracy and certainty reduce the required amount of required system margin that must be allocated to guarantee reliable optical connectivity. The remaining margin can then be applied toward increased transmission capacity, or a reduced number of regenerators in the network. We demonstrate the quality of transmission prediction experimentally in an optical mesh network with 0.6 dB Q-factor accuracy, and quantify the benefit in terms of network capacity gain in metro networks by impairment-aware network simulation.

Four wave mixing in ultra-dense WDM hybrid PON with wavelength-drifting coarse WDM optical transmitters

The unusual characteristics of the proposed ultra-DWDM PON architecture using CWDM burst transmitters and 1.3 µm SOAs prompt for experimental study of non-linear effects. A minimum channel spacing of 0.2nm was determined.

High-capacity upstream DWDM extended reach PON based on colourless CWDM transmitters with single nominal wavelength

We propose for the first time a colourless access architecture with 128 split-ratio, 60 km reach and expandable upstream capacity, based on conventional GPON B+ transceivers and sharing cost-effective amplifiers.

Video Overlay in Next Generation Passive Optical Networks

We propose and demonstrate a novel PON architecture to increase bandwidth per user and to alleviate degradation of analog video due to Raman crosstalk. Measurements of carrier-to- spur ratio of analog video overlay are presented.

Wavelength conversion using four-wave mixing with two nondegenerated pumps in a wavelength-selectable laser

We demonstrated four-wave mixing (FWM) with two pumps in a wavelength selectable laser to achieve a wide conversion bandwidth. Non-degenerated FWM with dual pumps in SOAs has been proposed to flatten the conversion efficiency variation accompanied with the variation of detunings between input signal and output conjugate. By utilizing a wavelength selectable laser, this complex scheme can be easily realized by a single device. We used a wavelength selectable laser, which consists of an 8-channel DFB laser array connected to an multi-mode interference (MMI) combiner with an SOA at its output. The DFBs had different lasing wavelengths with 3.18 nm spacing. We introduced a signal wave through one of the DFB lasers, and two of the lasers were used as pump sources. The wavelength of the signal and one of the pumps were fixed. The wavelength of the output conjugate was changed by switching to a different second pump laser. Conversion efficiencies between -14 and -16 dB were observed with wavelength detunings between 8 and 27 nm. An efficiency variation as small as 2 dB over a 2 THz frequency detuning range was achieved, in contrast to more than 5 dB variation in single pump schemes.