Ton Koonen

Fiber to the Home/Fiber to the Premises: What, Where, and When?

After conquering the core and metropolitan networks, fiber is now penetrating into the access domain. Its low loss and huge bandwidth enable the delivery of any current and foreseeable set of broadband services, and also make it a nice match to the wireless link to the end user. Cost effectiveness is a key issue, and will be decisive for the network topology choices. Point-to-point may be the most cost-effective for short-reach access, whereas point-to-multipoint may be the most interesting at medium- to long-reach access, or when line terminations in the local exchange become a key issue. A number of optical techniques being deployed for shared-fiber multiple access are discussed, based on time slot multiplexing, frequency slot multiplexing, code division multiplexing, and wavelength multiplexing, including their application in fiber to the home/fiber to the premises (FTTH/FTTP) networks for fast data transfer (asynchronous transfer mode (ATM) or Ethernet based) and for broadband service distribution (such as CATV). In the research laboratories, techniques aiming at next-generation optical access are being studied, such as wavelength routing for flexible capacity allocation and easily adaptable hosting of services and service providers, and radio-over-fiber techniques creating a powerful symbiosis of the fiber world and the wireless world by enabling centralized radio signal processing

Optical packet routing in IP-over-WDM networks deploying two-level optical labeling

Assigning a wavelength label as well as a label in a DPSK modulation format orthogonal to the data payload significantly increases the forwarding and routing capabilities of optical packet routers in IP-over-WDM networks.

Plastic optical fiber technology for reliable home networking: overview and results of the EU project pof-all

The rising performance of broadband connections for residential users, particularly in conjunction with fiber to the home, will present a new challenge for telecom operators in the short and medium terms: how to deliver the high bit rate digital signals with high quality-of-service to all consumer devices scattered inside the building of final users? Among the many different solutions for the home network, we review in this article the use of polymer optical fibers for short-reach and high-capacity optical communications for residential customer premises. POF is an easy-to-install, low-cost, and eye-safe solution for these networks, with the potential of being future-proof. In this article the state of the art in POF technology is presented by summarizing significant results achieved in the European project POF-ALL. Data transmission rates of more than 1 Gb/s over 50+ m and 100 Mb/s over 200+ m of standard step-index POF have been shown.

In-House Networks Using Multimode Polymer Optical Fiber for Broadband Wireless Services

A novel system concept is presented to transport microwave signals over an in-house multimode graded-index polymer optical fiber network, in order to feed the radio access points in high-capacity wireless LANs. By employing optical frequency multiplying, the networks intrinsically limited bandwidth is overcome. The feasibility of this concept to carry data at several hundreds of Mbit/s speed for various microwave signal formats at carrier frequencies in the tens of GHz range is shown. The concept enables cost-effective system implementation, and easy upgrading by offering data signal transparency. It can readily be integrated with other system technologies such as wired Gigabit Ethernet in a single multi-service in-house polymer optical fiber network.

Optically Tunable Frequency-Doubling Brillouin Optoelectronic Oscillator With Carrier Phase-Shifted Double Sideband Modulation

An optically tunable frequency-doubling optoelectronic oscillator (FD-OEO) based on stimulated Brillouin scattering (SBS) and carrier phase-shifted double sideband (CPS-DSB) modulation is proposed and demonstrated. SBS effect provides narrowband filtering for the OEO to generate an oscillation signal with frequency equal to the Brillouin frequency shift, while a CPS-DSB modulation by using a dual-parallel Mach-Zehnder modulator is implemented to double the oscillation frequency. Owing to the wavelength-dependent Brillouin frequency shift, frequency tunability is realized by tuning the wavelength of the laser source. In the experiments, frequency-doubling microwave signals from 18.38 to 18.74 GHz are generated when the wavelength of the laser source is tuned from 1565 to 1535 nm.

Compact spatial multiplexers for mode division multiplexing

Spatial multiplexer (SMUX) for mode division multiplexing (MDM) has evolved from mode-selective excitation, multiple-spot and photonic-lantern based solutions in order to minimize both mode-dependent loss (MDL) and coupler insertion loss (CIL). This paper discusses the implementation of all the three solutions by compact components in a small footprint. Moreover, the compact SMUX can be manufactured in mass production and packaged to assure high reliability. First, push-pull scheme and center launch based SMUXes are demonstrated on two mostly-popular photonic integration platforms: Silicon-on-insulator (SOI) and Indium Phosphide (InP) for selectively exciting LP01 and LP11 modes. 2-dimensional (2D) top-coupling by using vertical emitters is explored to provide a coupling interface between a few-mode fiber (FMF) and the photonic integrated SMUX. SOI-based grating couplers and InP-based 45° vertical mirrors are proposed and researched as vertical emitters in each platform. Second, a 3-spot SMUX is realized on an InP-based circuit through employing 45° vertical mirrors. Third, as a newly-emerging photonic integration platform, laser-inscribed 3D waveguide (3DW) technology is applied for a fully-packaged dual-channel 6-mode SMUX including two 6-core photonic lantern structures as mode multiplexer and demultiplexer, respectively.

Trends in optical access and in-building networks

As users require ever more speed, variety and personalization in ICT services, the capacity and versatility of access networks needs to be expanded. The first generation of point-to-point and of point-to-multipoint time-multiplexed passive optical networks (PON) is being installed. More powerful wavelength-multiplexed and flexible hybrid wavelength-time multiplexed solutions are coming up. Radio-over-fibre techniques create pico-cells for high-bandwidth wireless services. Next to bringing the bandwidth luxury to the doorstep, it must be distributed inside the userpsilas home. By advanced signal processing techniques, high-capacity wired and wireless services are jointly distributed in a low-cost converged in-building network using multimode (plastic) optical fibre.

Flexibly Reconfigurable Fiber-Wireless Network using Wavelength Routing Techniques: The ACTS Project AC349 PRISMA

A dynamically reconfigurable fiber-wireless network using flexible wavelength routing techniques is proposed by the PRISMA project, which offers a “forecast-tolerant” solution for handling a wide variety of wireless services and capacity demands as may emerge in the fast evolving market of mobile communications. This approach can considerably increase the operation efficiency of wireless networks for broadband nomadic services (wireless LANs). It also supports the evolution from GSM and GPRS towards UMTS, and the entry of new operators and/or services into the liberalized mobile communications market. The system has been implemented in a field trial and has been operated successfully with real users and broadband nomadic services. The system concept is ready for further development into products.

Beyond 1 Gbit/s Transmission Over 1 mm Diameter Plastic Optical Fiber Employing DMT for In-Home Communication Systems

Multi-Gbit/s transmission over 1 mm diameter graded index plastic optical fiber (GI-POF) is reported. Transmission rates between 5.3 and 7.6 Gbit/s are achieved for fiber lengths between 10 and 50 m using discrete multi-tone modulation (DMT) in an intensity modulated direct detection system using directly modulated eye-safe VCSEL and silicon photodiode (PD). The used system bandwidth is only 1.42 GHz resulting in a spectral efficiency of bits/s/Hz. All employed components represent a low-cost, off-the-shelf cost-effective solution for high-speed in-home communication systems.

Demonstration of a Photonic Integrated Mode Coupler With MDM and WDM Transmission

In this letter, 3.072-Tb/s (six spatial and polarization modes × 4 wavelength-division multiplexing (WDM) ×128-Gb/s 16QAM) transmission over 30 km of few-mode fiber (FMF) is demonstrated employing a photonic integrated mode coupler based on silicon-on-insulator (SoI) technology. A 2-D top coupling solution with five small vertical grating couplers is proposed for coupling between an SoI chip and an FMF, guiding LP01 and LP11 modes. Push-pull and center launch configurations for exciting LP11 and LP01 modes, respectively, through mode-profile matching are analyzed and implemented on the SoI chip.