M.A. Romero

All silica S-band double-pass erbium-doped fiber amplifier

Double-pass (DP) and single-pass (SP) erbium-doped depressed cladding fiber amplifiers designed for S-band operation are evaluated under changes of the input optical power, pumping power, and fiber bending radius. The DP configuration employs the usual combination of a circulator and a Faraday rotator mirror while the SP is based on the copropagating scheme. The amplifiers were characterized in terms of gain and noise figure. It is demonstrated that the DP topology shows much improved gain performance compared to the SP configuration although the noise figure is slightly degraded by counterpropagating amplified spontaneous emission.

S-C-L triple-band double-pass erbium-doped silica fiber amplifier with an embedded DCF module for CWDM applications

In this paper, the authors present a double-pass triple-band doped fiber amplifier including an embedded dispersion-compensating fiber. The amplifier employs only silica-based erbium-doped fibers to achieve signal amplification over S-, C-, and L-bands. Experimental characterization is carried out in terms gain and noise figure over the coarse-wavelength-division-multiplexing (CWDM) wavelength grid. By providing optical gain to seven CWDM channels spectrally located between 1490 and 1610 nm, the amplifier can extend the reach of a CWDM optical bus well beyond the 100-km limit

Analysis of ASE-Related Impairments on Wavelength-Reuse WDM-PONs Based on Self-Seeded Reflective SOAs

We experimentally investigate the impact of chromatic dispersion (CD), post-filtering effects (PFEs), and backreflection-induced penalties on intensity-remodulation topologies based on self-seeded directly modulated reflective semiconductor optical amplifiers (RSOAs) acting as downstream carriers. Optical eye diagrams and power penalties as a function of link reach and reflection tolerances, as well as optical spectra and bit error rate (BER) performance up to 100 km, are measured and directly compared to a conventional prespectrum slicing light (PSSL) injection topology, in order to highlight the advantages and drawbacks of the self-seeding scheme. Downstream and bidirectional reaches up to 80 and 60 km, respectively, with a maximum 2 dB power penalty (for a BER of 10-12) at 1.25 Gb/s operation are demonstrated in our self-seeding configuration, which enables enhanced resilience to CD and PFE effects while surpassing the conventional PSSL scheme in about 40 km.

All silica triple band double pass EDFA for CWDM applications

A broadband double-pass EDFA is characterized over the CWDM grid from S to L bands. It relies only on silica fibers, being capable of extending the network reach beyond the 120 km limit.

Polarization analysis in double-pass erbium-doped fiber amplifiers with an embedded-DCF module

Two configurations of double-pass erbium-doped fiber amplifiers with an embedded dispersion-compensating module are evaluated under changes of the input optical polarization. The first configuration employs the usual combination of a polarization-beam splitter and a Faraday rotator mirror (FRM), while the second is based on the use of two circulators. The amplifiers are characterized in terms of polarization-dependent gain, noise figure, and BER. It is demonstrated that the topology employing circulators show much improved performance compared to the configuration using the FRM.

A fiber-optic Bragg-grating temperature sensor for high-voltage transmission lines

In this work a new fiber-optic temperature sensor is proposed. The device is based on Bragg gratings photoinduced on the optical fiber core and it is intended for temperature monitoring of electric power systems and high-voltage transmission lines. In contrast to most published work the sensor does not rely on interferometric techniques. The procedure being proposed employs a dual-wavelength measurement of the optical power being reflected (or transmitted) by a Bragg mirror in order to track temperature variations, simultaneously cancelling spurious readings due to source power fluctuations, fiber attenuation, losses, etc. Preliminary results are presented and a possible experimental implementation is discussed.

80 km extended Gigabit Passive Optical Network

This work describes the experimental demonstration of a 80 km-reach PON system, with a 1:128 split ratio, using a conventional Gigabit-Capable Passive Optical Network (GPON) equipment. The experiment was made possible by the use of bidirectional 1310/1490 nm semiconductor optical amplifiers (SOAs) as well as by a change on the medium access control (MAC) protocol. Results for packet-loss ratio and power budget are given as a function of split ratio and network reach of a field-trial PON.

Requirements for efficient raman amplification and dispersion compensation using microstructured optical fibers

Abstract The design and performance of microstructured optical fibers (MOFs) for simultaneous dispersion compensation and Raman amplification is numerically investigated. We studied a lumped Raman amplifier designed to compensate the signal loss and dispersion introduced by a 100-km, 16-channel C-band WDM link. The impairments induced by the nonlinearities caused by the small mode area of the designed MOF are investigated and the analysis is extended to include non-ideal factors such as excess background losses, splice loss, and the geometry variations during the fabrication process. The results are discussed and compared to those obtained for conventional dispersion compensating fibers (DCFs).

A WDM-PON implementation employing spectrum sliced ASE source, dispersion management and PIN receivers

In this work we propose a novel wavelength division multiplexing passive optical network (WDM-PON) configuration. The system is based on a colorless optical source employing the injection of amplified spontaneous emission (ASE) into a reflective SOA (R-SOA). In addition, optical detection at the ONTs is carried out by PIN based receivers, without decision threshold level adjustment (DTLA). We investigated the system performance for four directly modulated 1.25 Gb/s channels at the C-band in the presence of chromatic dispersion and experimentally demonstrated error free operation for downstream traffic in a 20 km reach, with 1.0 dB penalty.

Comparative analysis of optical amplifiers for CWDM networks

We present a cost-effective EDFA configuration for CWDM applications, using a combination of parallel and series circuits. The developed CWDM EDFA was characterized for gain and noise figure from 1490 to 1610 nm (S, C and L bands) and its performance was evaluated in terms of BER for power and line applications. The obtained results are compared to those arising from the use of a CWDM SOA under the same experimental conditions.