Cristina Arellano

Optical network unit based on a bidirectional reflective semiconductor optical amplifier for fiber-to-the-home networks

An optical access network transceiver based on a reflective semiconductor optical amplifier operating as modulator and photodetector is demonstrated. Device characterization and modulation/detection tests show the system proper operation at 1.25 Gb/s to 30-km reach. This optical network unit design is a simple and capable solution for future fiber-to-the-home networks.

Full-duplex single fiber transmission using FSK downstream and IM remote upstream Modulations for fiber-to-the-home

Full-duplex single fiber bidirectional transmission, using frequency-shift-keying modulation for downstream, by direct modulation of a tunable laser, and intensity modulation for upstream, in a wavelength-division-multiplexing passive optical access network is demonstrated. The optical network unit, located at the end user premises, reflects and orthogonally remodulates the received light. Rayleigh scattering effects are reported and analyzed. The system shows proper operation up to 1 Gb/s at 30-km reach.

Reflections and Multiple Rayleigh Backscattering in WDM Single-Fiber Loopback Access Networks

The optical gain of reflective optical network units (ONUs) may produce a critical amplifying feedback on the single-fiber transmission impairments. In this paper, its influence on the passive optical networks transmission with reflective-ONU is theoretically analyzed and experimentally confirmed. Analytical expressions for the optical crosstalk-to-signal ratio and the Q-parameter in presence of Rayleigh backscattering, reflection interferences and ASE noise are given. As a resulting design guideline, the ONU gain should be adjusted to about 3 dB below the total link loss; in addition, component return loss at the drop section must be higher than 30 dB. Experimental results with two basic types of reflective-ONUs, namely a loop structure formed by a Mach-Zehnder modulator and an optical amplifier, and another one employing a reflective-SOA, are in agreement with the theoretical approach.

RSOA-based optical network units for WDM-PON

Designs of low cost ONU for WDM-PON are presented and evaluated. Reflective-SOAs are proposed to be used as core of the ONU in a bidirectional single-fiber single-wavelength topology. FEC is employed to mitigate crosstalk effects

Rayleigh Scattering Reduction by Means of Optical Frequency Dithering in Passive Optical Networks With Remotely Seeded ONUs

With the purpose of reducing the crosstalk caused by Rayleigh scattering in bidirectional centralized light systems, we propose and experimentally demonstrate an optical frequency modulation to broaden the optical spectrum effectively. Analytic expressions for the Q-parameter of the signal affected by Rayleigh backscattering are also given and experimentally checked, both for optical frequency stable and dithered sources

Bidirectional single fiber transmission based on a RSOA ONU for FTTH using FSK-IM modulation formats

Full-duplex bidirectional transmission using FSK modulation for downstream and remote IM using a reflective SOA for upstream in a single-fiber WDM-PON access network is demonstrated. The system shows proper operation at 1 Gbit/s to 30 km reach.

Optimization of Rayleigh-Limited WDM-PONs With Reflective ONU by MUX Positioning and Optimal ONU Gain

In this work, the influence of the distribution element position and the reflective optical network unit (ONU) gain in wavelength-division-multiplexing passive optical networks are reported. After the theoretical and experimental analysis, it is determined that the best crosstalk-to-signal ratio is achieved if the multiplexer is placed either in the ONU or optical light termination vicinity, and the ONU gain has a new optimum value depending on the position. Also, it is demonstrated that Rayleigh backscattering is generally irrelevant in downstream transmission.

Hybrid Dual-fiber-Ring with Single-fiber-Trees Dense Access Network Architecture using RSOA-ONU

A long-reach, high-density centralized-light access network using remote amplification and Reflective SOA for upstream remodulation in a user-single-fiber completely passive WDM-PON providing broadband to >1000 users distributed along large distances is presented.

Recent Developments in WDM-PON Technology

Considerable research is being conducted to exploit the potential of novel WDM-PONs exhibiting individual, data and protocol agnostic virtual point-to-point (p2p) links for each ONU. The research focuses on the deployment of uniform building blocks throughout the entire access network and on upgrading the channel data rate efficiently towards 10 Gb/s. This contribution gives an overview of basic principles of WDM-PONs, discusses merits and drawbacks of related approaches and highlights important requirements for key components such as injection-locked Fabry-Perot lasers, (R)SOAs, SLEDs and athermal AWGs

Resilient single-fiber ring access network using coupler-based OADMs and RSOA-based ONUs

An extended PON access network based on a central single-fiber ring and secondary trees is presented and experimentally demonstrated. The architecture provides resilience and load balancing mechanisms that are totally transparent to the end users.