Victor Polo

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.

Direct Phase Modulation DFBs for Cost-Effective ONU Transmitter in udWDM PONs

A technique for direct phase modulating a low-cost distributed feedback laser is presented for user transmitter in ultra dense wavelength division multiplexing passive optical networks. It consists of a simple RC network, which equalizes the phase response. The method is tested with differential phase-shift keying modulation and heterodyne coherent detection at 1.25 and 2.5 Gb/s showing a penalty <;1 dB at BER = 10-3 compared with external phase modulation.

Remotely amplified combined ring-tree dense access network architecture using reflective RSOA-based ONU

Feature Issue on Passive Optical Network Architectures and TechnologiesA highly scalable access architecture achieving high density and featuring resiliency, centralized light-generation control, remote amplification, and colorless optical network unit with reflective semiconductor optical amplifier (RSOA) for upstream modulation is presented and experimentally demonstrated. It is based on a user-single-fiber completely passive outside plant and provides broadband connections to >1000 users distributed along large distances. It is believed to represent an intermediate step toward metro-access convergence and offers flexible configurations covering high- and low-density population areas.

10 Gb/s RSOA transmission by direct duobinary modulation

An ultra low-cost electronic solution to achieve 10 Gb/s transmission by means of passive equalization and duobinary encoding using an RSOA with 1.5 GHz electrical bandwidth is demonstrated.

Demonstration of a Remotely Dual-Pumped Long-Reach PON for Flexible Deployment

We propose and experimentally demonstrate a flexible wavelength division multiplexing/time division multiplexing network architecture for converged metro-access environment. Entire passiveness in the fiber plant is achieved with remote amplification in the signal distribution nodes along the metro ring and in the power splitters of the local access tree. We assist a traditional remote pumping scheme with a distributed pump provided by the optical network units and demonstrate that loss budgets beyond 30 dB can be supported. Data transmission of up to 10 Gb/s is evaluated in different deployment scenarios, reaching from a 78 km long reach rural to a dense 1:128 split/λ urban configuration with field installed fibers, including also worst case resilience configurations.

Simultaneous optical label erasure and insertion in a single wavelength conversion stage of combined FSK/IM modulated signals

We report on optical label swapping of combined frequency-shift keying/intensity modulation (FSK/IM) modulated signals by using a single wavelength conversion stage based on a semiconductor optical amplifier Mach-Zehnder interferometer. Simultaneous FSK label erasure and insertion at a bit rate of 156 Mb/s is successfully achieved for a 10-Gb/s IM payload with transmission over two spans of 40-km standard single-mode fiber.

Experimental demonstration of a statistical OFDM-PON with multiband ONUs and elastic bandwidth allocation [invited]

The statistical orthogonal frequency division multiplexing passive optical network (OFDM-PON) concept with multiband optical network units (ONUs) is experimentally tested with two users and an optical line terminal at 2.5/5 Gb/s total effective capacity with binary phase-shift keying (BPSK)/quadrature phase-shift keying (QPSK) modulation. Both downstream and uplink were measured based on intensity modulation and direct detection. The ONUs consisted oflocal nonpreselected wavelength distributed feedback laser sources centrally controlled to reduce overlapping probability. In addition, a radio-frequency mixing stage in the ONUs up/downconverts the user data to/from the OFDM signal, reducing the computational effort. Compared with ONUs processing the whole signal, the multiband approach presents comparable results with almost symmetrical power budgets of around 25 and 20 dB with BPSK and QPSK, respectively, which could increase up to 4.5 dB by allocating a spectral guard interval between the optical carrier and the OFDM data. Furthermore, elastic bandwidth allocation is explored, which is shown to compensate for up to 18 dB differential link loss.

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.