Juan José Martínez

Multiple-bit all-optical logic based on cross-gain modulation in a semiconductor optical amplifier

In this paper we have evaluated the non-linear response of a semiconductor optical amplifier (SOA) in terms of Cross Gain Modulation effect (XGM). The different ranges of optical power that make the SOA work as a logic gate have been determined, as well as the optimum relation between inputs to obtain the best response. Taking into account the SOA response, a schematic model for an all-optical 4-input NOR gate using a single SOA has been proposed. Our experimental set-up has been tested with four streams of 10 Gbps RZ data to verify the proper and stable operation of the NOR gate under diverse power levels for each data input. The logic output has been evaluated for different inputs using an optical eye diagram to verify its quality; in addition, the possibility of using the NOR output as the input to other logical semiconductor structures, which would allow to chain multiple gates, has been demonstrated. The concatenation of NOR gates allows to build more complex all-optical devices which will permit the design of advanced mechanisms in the field of transparent networks, such as comparators or look-up tables for switching nodes, without the necessity of optical-electrical conversion.

Integrated Multi-Bit All-Optical NOR Gate for High Speed Data Processing

In this paper, we study the use of integrated semiconductor optical amplifiers as the basic building block for larger-scale programmable photonic circuits. Making use of the non-linear response of these devices, we study the performance of 4-bit all-optical NOR gates based on fully integrable components for high speed all-optical look up tables. Feasibility of the proposed architecture is demonstrated by proof-of-concept experiments using both commercially available devices and photonic integrated circuits.

Programmable all-optical logic gates based on semiconductor optical amplifiers

In this paper, we discuss the feasibility of optical programmable logic devices based on non-linear processing with semiconductor optical amplifiers. We report results from the simulation of the architecture of an all-optical 4-bit Look-up Table, which is the basic logic element of larger-scale programmable devices, and experimental results from a proof-of-concept setup using commercially available devices. Experimental work with photonic integrated circuits to assess the feasibility of integration of such architectures is also presented.

All-optical in-band OSNR measurement in intensity-modulated direct-detection optical OFDM systems

In-band OSNR measurement for IM/DD O-OFDM systems using high-resolution spectral analysis is experimentally demonstrated. It is shown that noise level can be monitored by direct optical spectrum analysis using no polarization analysis or coherence properties and avoiding the need for data demodulation.

WDM Ethernet PON based on downstream narrow-FSK modulation

We propose and test experimentally a GbE PON architecture based on downstream narrow-FSK modulation, obtained by direct modulation of a DFB laser and upstream transmission achieved by intensity modulation of the FSK signal within a colorless user terminal.

Novel in-band OSNR monitoring system based on a polarization interferometer

In this communication we propose a OSNR measurement system capable of perform in-band measures of optical noise in OOK/PSK channels. Our design takes advantage of the noise polarization insensibility, using a polarization interferometer to discriminate it from the signals.

Four-input NOR gate using cross gain modulation in a single Semiconductor Optical Amplifier

We demonstrate all-optical NOR logic operation of four data signals in one SOA. Exploiting XGM, wavelength multiplexing and optical filtering for signal discrimination, we purpose an implementation in which an all-one optical probe signal is modulated by the optical sum of four different data signals at 10 Gbps each. Data signals act as pump and reduce the gain of the SOA producing on-off keying of the probe and, hence, the NOR behavior. We derive the feasibility of a multiple-bit NOR from a simple XGM setup working at a wide range of pump power by means of a characterization with all-one RZ streams. High-resolution measures of the signals are presented to illustrate nonlinear effects and wavelength management. Signals traces are showed to prove logic functioning and 4-bit gate quality is reported by means of eye diagrams of the output signal for different input powers.

Integrated all-optical 4-input NOR logic gate based on InP technology

In this work we present an integrated all-optical 4-input NOR logic gate fabricated on InP technology and comprising a fabricated SOA operating at 25 Gb/s and a wavelength demultiplexer. This logic gate may be the base for the development of 4-input look-up tables, needed for the development of larger-scale all optical programmable devices.

Assessment of linear semiconductor amplifiers for upgrading WDM-PONs with wavelength reuse

In this work we have assessed the capacity of a linear semiconductor optical amplifier to compensate the fiber and component losses present in a wavelength division multiplexing passive optical network (WDM-PON) evolution from fiber-to-the-building (FTTB) to fiber-to-the-home access. The evaluation measurements confirm that the presence of a semiconductor optical amplifier placed at the entry of a group of optical network units that share the same wavelength channel can raise the loss budget that the link can tolerate in the fiber, compensating for the losses of a passive splitter up to a 1:16 division rate, allowing the upgrade of existing WDM-PON FTTB structures to make the fiber reach the final users home.

Fiber to the Home Through Passive Optical Networks

This chapter presents a comprehensive overview of current deployed and novel proposed protocols and subsystem architectures for passive optical networks. Emphasis is given to link layer techniques that allow resource sharing emphasizing bandwidth utilization or so-called dynamic bandwidth allocation techniques. In the transport layer, methods for ONU remote-seeding and their limitations are described as they allow for cost reduction, which is of paramount importance in the access area.