Massimo Artiglia

• Master of Physics
• Senior Researcher at Consorzio Nazionale Interuniversitario per le Telecomunicazioni (CNIT)

We experimentally demonstrate an innovative UltraDense Wavelength Division Multiplexing (UDWDM) Passive Optical Networks (PON) that implements the full λ-to-the-user concept in a filterless distribution network. Key element of the proposed system is an innovative class of coherent transceivers, purposely developed with a non-conventional technical...

We demonstrate a coherent 10 Gb/s PON system solution exploiting a direct modulated laser (DML) transmitter to obtain long reach (>100 km). The system exploits a simplified coherent receiver. This receiver, which is similar to the scheme that we recently proposed, had to be adapted to obtain polarization-independent operation with a chirped signal...

Advantages offered by coherent detection systems in access networks are not limited to the increase of power budget due to the superior sensitivity. Channel selectivity is another intriguing feature offered by coherent systems that can be exploited to enable advanced system and network functionalities for access systems. Among them, we focus here o...

An UDWDM-PON with simple real-time ASK and DPSK transceivers at 6.25 GHZ channel spacing is validated in a field-trial with deployed fiber with power budget above 40 dB. This work presents final results of the Coconut European Project.

A 1.25-Gb/s ASK passive optical network (PON) system with a -51 dBm pre-FEC sensitivity (at BER = 2 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> ) is enabled by a real-time polarization-independent coherent receiver (PI-RX) that needs no DSP (nor ADC). The receiver, which only makes us...

Simplified coherent detection of directly modulated DFB transmitters allows for 55 dB ODN power budget in downstream of a 40 Gb/s DML-based WDM-PON with 110 km reach. The solution can enhance NGPON2, addressing long reach and high power budget links (>50 dB).

A coherent TX-RX prototype is presented including a real-time polarization-independent coherent receiver (PI-RX) with analog processing (no DSP). The prototype, realised by means of common DFBs and commercially available RF electronic ICs, is targeted for use on a 6.25 GHz Ultra Dense Wavelength Division Multiplexed (UD-WDM) grid and features up to...

A 1.25 Gb/s ASK PON system with -51dBm sensitivity (at BER=2∙10-3) is enabled by a polarization-independent coherent receiver that needs no DSP (nor ADC). The system just uses common DFBs and commercial electronic devices and has 52 dB dynamic range.

We demonstrate 10-Gb/s transmission over more than 130 km of G.652 fiber using a simple directly modulated distributed feedback (DFB) laser and a new "chirp-managed" approach based on a low-complexity coherent receiver. The "chirp-managed" effect, which has been obtained in the past by optical spectral reshaping, is conveniently achieved here by me...

We demonstrate experimentally a novel type of coherent low cost Gigabit-to-the-User Ultra-Dense-Wavelength Division Multiplexing (UD-WDM) PON, featuring 6.25 GHz channel spacing and long reach. Polarization-independent coherent detection is achieved by exploiting a novel scheme which requires only a 3 × 3 coupler, three photodiodes, basic analogue...

A 1.25 Gb/s ASK PON system with −51dBm sensitivity (at BER=2−10 3 ) is enabled by a polarization-independent coherent receiver that needs no DSP (nor ADC). The system just uses common DFBs and commercial electronic devices and has 52 dB dynamic range.

This paper presents the most significant results achieved in the last two years by our group in coherent ultra-dense-WDM PON for λ-to-the-user access. Here we mostly focus on the architectures based on simple OOK-NRZ modulation format. We demonstrated the real-time implementation of our coherent receiver and we proved its compatibility with direct...

Processing of high-frequency, wide-band signals is conveniently performed in the optical domain due to availability of optical filters which intrinsically have a wide-band response. On the other end, there are several application scenarios where very sharp pass-band filtering is required. In these cases, realizing the processing in the optical doma...

This paper presents the implementations and test results of the novel polarization-independent receiver for ASK format, realized in the framework of COCONUT FP7 Project. COCONUT exploits low-cost optical components and simple electronics, so that the cost of typical line terminals would be affordable to the end-users. Among the different technical...

We experimentally demonstrate a cost-effective coherent 10 Gbit/s system for Passive Optical Networks (PON), exploiting off-the-shelf DFB lasers and a phase-diversity receiver based on a simple 3×3 fiber coupler. Since the system uses a simple Amplitude Shift Keying format, no complex electronic processing is required and there is no need of freque...

We experimentally demostrate a 6.25 GHz grid WDM-PON based on commercially available directly-modulated DFB transmitters driven with a 650mVpp and simplified coherent receivers. The system can support 35dB distribution network losses and allows the λ -to-the-user approach.

Using fully-analogue and commercially available electronics, we realize a real-time coherent ONU receiver for Ultra-Dense WDM-PON based on intensity-modulated signals. The receiver also requires common photonic components and has -47dBm sensitivity at FEC level.

We demonstrate a coherent OFDM-PON based on a simplified coherent receiver, which exploits a DFB local oscillator without phase/frequency locking. We achieve ultra-narrow channel spacing (Δν = 1.6 GHz) and high-power budget (43 dB/35 dB) for 1.25/10 Gb/s.

Direct-detection of differential phase shifted keying (DPSK) optical signals is implemented either by ad hoc optical filtering or one-bit delayed optical interferometers. We show a coherent receiver where the filtering is performed in the electrical domain after down-converting the incoming signal to the baseband or to an intermediate frequency. Th...

131 km transmission (typical LR-PON distance) at 10Gb/s over G.652 fiber is demonstrated exploiting a direct modulated (DM) DFB laser, coherent receiver and electrical filtering obtaining an innovative chirp managed approach. No dispersion compensation (optical or DSP) is exploited.

The operation of an extended power budget long reach access network is experimentally demonstrated using commercially available small form pluggable directly modulated transmitters and a simplified coherent receiver free from digital signal processing and phaselocked loops. An ad-hoc choice of photodiode bandwidth allows no penalty compared with ex...

Experimental SPM, FWM and XPM contributions are separately measured. Evaluation of Q penalties is performed on a 2000-km, 33-GHz, 66-GHz and 100-GHz-spaced DWDM system. XPM is found to be the major constrain.

An electrical spectral technique to correctly evaluate cross-phase modulation behavior in intensity modulation-direct detection systems is proposed. Intrinsic advantages of the technique, in terms of high accuracy, are discussed in comparison with the classical time-domain method, which requires precise receiver noise characterization. Measures hav...

Nonlinearity-due Q penalties are experimentally evaluated on a 2000-km, 33-GHz spaced DWDM system, dependently on system length and channel spacing. SPM, FWM and XPM, which is found to be the major constrain, are separately addressed. Full Text at Springer, may require registration or fee

Spectral response of XPM impairments in WDM systems is evaluated by experimentally measuring NRZ signals XPM impact through a spectral electrical technique. The results are compared with classically adopted time domain measurements and found in good agreement also with the theoretical model.

An easy to implement experimental technique for good accuracy spectral characterization of Rayleigh backscattering recapture factor is presented. Measurements on two different fibers show good agreement with the theoretical model assuming 1/4 as proportionality coefficient.

A new relationship between polarimeter and interferometer measurements of polarization mode dispersion is proposed. This model bridges the gap between interferometer patterns and probability density function of the principal states of polarization group delay. Experimental results supporting the theory are presented.

We describe local birefringence measurements performed with a polarization sensitive OTDR on installed single-mode fibers. Results indicate that G.652 fibers are, on average, less birefringent than G.653 fibers.

Properties of the most common commercial fibres as regards their applications in high capacity DWDM systems are analysed. Potentialities of each fibre type are stressed with particular emphasis on limitations due to non linear effects and extended band amplification.

Current wideband optical fiber amplifiers (OFA) capable of expanding the operation band of wavelength division multiplexed (WDM) telecommunication systems are reviewed. Among the various options, that of parallel C+L amplifiers permits gradual increases in system performance as part of a strategy where the device is optimized in the system. The erb...

Through a two-step method based on the combination of stretching a preform and overcladding it with a mechanically drilled glass bar, Er 3+ doped single-mode fluoride optical fibers were obtained. With the best of these, presenting an attenuation of 0.48 dB/m 1.3 μm, an EDFFA (Erbium Doped Fluoride Fiber Amplifier) was constructed which showed a sm...

The need for ever-higher transport capacity is one of the main drivers behind the ongoing technological advances in Optical Fiber Amplifiers (OFAs) for use in WDM (Wavelength Division Multiplexing) systems. Widening the gain band of erbium-doped OFAs provides immediate potential for increasing the total capacity of such systems, making it possible...

A successful 10 Gbit/s transmission experiment over 192.2 km of conventional fiber carried out using a commercial chromatic dispersion compensating fiber is described. The experiment made it possible to verify several criteria for optimal dispersion compensating fiber placement along the link, demonstrating the effectiveness of the simultaneous pre...

A technique is presented for the high-resolution measurement of spectral non-linear gain characteristics, due to the effect of Brillouin optical scattering in telecommunications fibers. Potentially, this method allows determining all the parameters that characterize the Brillouin gain: linewidth, linear gain coefficient, and peak frequency shift (w...

The behaviour of the Polarisation Mode Dispersion (PMD) in various types of optical fibre amplifiers has been studied by the European consortium FAME (Fibre Amplifier Measurement Methods). We present some guidelines for precise measurement of PMD in amplifiers. Our main result is that the PMD of such devices is inherently deterministic and can be s...

Measurements performed in the framework of the FAME Project show that the polarization mode dispersion (PMD) in optical fiber amplifiers is deterministic, at least for erbium-based devices. Results show that reliable measurements of the differential group delay in the amplifier bandwidth are feasible with the device in operating conditions. This as...

The longitudinal distribution of chromatic dispersion in G.653 fiber links is important to evaluate the impact of nonlinearities in multichannel telecommunication systems. Normally characterizations are performed in terms of average values for the zero-dispersion wavelength X, and slope S. Various methods have been proposed to measure the dispersio...

Citation M. Artiglia, "Comparison of dispersion-compensation techniques for lightwave systems," in Optical Fiber Communication Conference, Vol. 2 of 1998 OSA Technical Digest Series (Optical Society of America, 1998), paper ThV2. http://www.opticsinfobase.org/abstract.cfm?URI=OFC-1998-ThV2

Two methods relying on the Four-Wave Mixing effect for the measurement of the longitudinal distribution of the zero-dispersion wavelength in an optical link have been successfully implemented. One of these set-ups is based on a commercial Optical Time-Domain Reflectometry apparatus. The results obtained with the two techniques are in excellent mutu...

Gain-slope measurements on three different types of erbium-doped amplifiers for analogue applications are presented and discussed. The results clearly show that care must be exercised when using erbium-ytterbium codoped fibre amplifiers. Standard EDFAs and fluoride fibre EDFAs seem to give better performance

COST 241 measurements of the nonlinear refractive index, n₂, exhibit a large scatter depending on the specific measurement technique. This is largely due to the electrostrictive contribution to the Kerr nonlinearity, as is revealed by the resonant behaviour of n₂ (with peak values up to 3.9 10^-20 m² W<su...

As part of studies of nonlinear processes on optical fibers, a technique capable of producing continuous sequences of optical solitons was tested. Solitons can be used for high bit-rate connectionswith nonlinear propagation. To this end, it is essential to have a source of continuous soliton sequences with a repetition frequency equal to the bit-ra...

Successful transmission of a 2.5 Gbit/s directly modulated signal is achieved in conventional single mode fiber well beyond the dispersion limit. Spectral inversion is obtained by exploiting the parametric gain of Modulation Instability in a Dispersion Shifted fiber, obtaining a record conversion efficiency.

The paper discusses the new optical transmission system technologies and their technical motivations. The present applications in the Italian transport network are reviewed, along with critical economic issues, and an evolution scheme of the optic network architecture is proposed.

Most of the installed fibre in optical networks is of conventional type with high chromatic dispersion around 1550 nm, where erbium doped optical fibre amplifiers do operate. Thus dispersion compensation will be required to upgrade the capacity of installed fibre links to 10 Gbit/s and beyond. The paper gives a survey of the various dispersion comp...

The paper describes three methods-spectral interpolation, polarization nulling, and pulse recovery-for the measurement of the optical parameters needed to determine the noise figure of erbium doped fiber amplifiers. The three techniques are experimentally compared, allowing us to conclude that the polarization nulling method is the more accurate an...

To upgrade existing conventional fibre lines to very high data rates, effective methods of coping with the chromatic dispersion problem are therefore needed. Several techniques for the compensation of chromatic dispersion have been suggested so far. They include the use of externally modulated chirp-free transmitters, pre-chirping techniques of the...

Summary form only given. Mid-span spectral inversion can overcome the limitations set by chromatic dispersion on high-bit-rate transmission based on conventional fibers (i.e., fibers dispersion-optimized at 1300 nm) and combat fiber nonlinearities. Here we demonstrate a high efficiency and cost saving optical spectral inverter (SI) exploiting the m...

A novel experimental technique for the measurement of the nonlinear refractive index coefficient,n2, based on the detection of self-phase modulation phase shift by means of an all-fiber Sagnac interferometer, is proposed. Measurements performed on dispersion-shifted fibers clearly indicate that the value ofn2at 1550 nm is around 2.5 × 10−20m2/W, co...

Results of polarization mode dispersion (PMD) measurements performed on an undersea optical cable are presented. Two different techniques wave used: the Poincare sphere method and the fixed polarizers method. Comments on the impact of the measured PMD values on system performance are also presented.

This paper presents the results of a high-speed multichannel transmission experiment over 200 km of conventional optical fibre, optimized in dispersion for operation at λ = 1310 nm. With dispersion compensating fibres providing partial compensation for line chromatic dispersion, a wavelength division multiplexing 4 × 2.5 Gbit/s system using DFB dir...

The paper describes propagation experiments carried out in CSELT using an optical-fibre recirculation-loop. Results of linear and nonlinear characterisation of optical lines with cascaded amplifier chains and long distance transmission experiments of 2.5 Gbit/s pulse sequences are discussed. The effects of modulational instability, four-wave mixing...

The power and polarisation dependence of modulation instability were experimentally investigated and used to obtain a novel, simple and accurate method for the measurement of Kerr coefficient in optical fibres. New results on dispersion shifted fibres are reported, giving n ₂=2.64×10²⁰m²/W at 1553 nm (linear polaris...

A 2.5 Gbit/s long distance transmission experiment is performed at 1550 nm utilizing a recirculating fibre loop configuration and a RZ (Return to Zero) modulation format. Operation with BER<10-9 is achieved over 1000 km of standard single mode fibre by using a dispersion compensating fibre in the loop.

A new time-resolved method for the measurement of the non-linear refractive index n2 in optical fibres, based on a Sagnac interferometer, is proposed. First experimental results, yielding n2 = 2.6·10-20 m2/W, demonstrate the feasibility of this simple self-compensating scheme.

The development of optical fibre amplifiers has caused an impressive evolution in optical telecommunications systems since the end of the 1980s. The widespread application of active fibre amplifiers requires accurate tools to design and simulate these devices in very different operating conditions. The present work describes some physical aspects o...

Not Available

An intercomparison of measurements on three Er-doped fibres has been organized in the working group 3 of the Europeean COST 217 project (optical measurement techniques for advanced optical fibre systems and devices). A set of fibre parameters, including core diameter, refractive index difference, mode field diameter, cut-off, absorption, fluorescen...

A theoretical model of rare earth doped fiber amplifiers is presented, which takes into account the combined effects of modal structure of the fields propagating into the guide and dopant concentration distribution. From it the realistic evolution along the fiber of pump, signal and amplified spontaneous emission, local pump absorption and signal a...

The results of an extensive intercomparison of OTDR measurements on three types of single mode fibres, organised in the framework of the European Project COST 217, are presented and discussed. Seventeen laboratories from all over Europe participated to the intercomparison. The results show an acceptable agreement, particularly in attenuation measur...

A new discretisation procedure based on a finite difference approach is presented for the analysis of arbitrary two-dimensional optical dielectric waveguides. It is based on a longitudinally variant discretisation grid that allows an accurate treatment of waveguide changes of geometry to be obtained. Comparisons with the well known beam propagation...

An interlaboratory comparison of measurements of mode field diameters, involving 15 European laboratories has been organized and carried out within the framework of CEC Project COST 217 (Working Group 1). Six fibres of different design have been measured and almost all of the measurement methods known in the literature investigated. Among them the...

An interlaboratory comparison of mode field diameter measurements on six single mode fibres of both conventional and dispersion modified design has been performed within the framework of the COST 217 Project. Fourteen laboratories took part in the intercomparison using five different measurement techniques. The results showed clear systematic diffe...

The importance of the numerical simulation of integrated optics devices for optical telecommunication systems is constantly growing and much attention is being devoted to the development of new powerful and effective numerical codes for solving the paraxial wave equation for planar structures. However, the numerical techniques so far presented are...

A finite difference method based on a Crank-Nicolson discretisation procedure has been implemented and applied to the analysis of propagation of optical beams in dielectric waveguides. It is based on a new formula which takes into account the correct boundary conditions. Comparisons with the well known BPM technique show a definite improvement in c...

A quick technique for the characterization of a single-mode fiber in terms of cutoff wavelength is proposed. The technique is a 'go-no go' test, very quick (two measurements at a single wavelength are necessary), and can be considered as an alternative to the usual transmitted power method. The proposed technique gives good results also in presence...

Measurement procedures for the optical characterization of fibre couplers are proposed which are suitable for couplers which are both wavelength and polarization dependent. The necessity of using unpolarized light (P < 0.05) when measuring the wavelength dependence of coupling ratio has been demonstrated. For the measurement of the polarization sen...

The accuracy of Transmitted Near-Field Intensity measurements for the determination of Mode Field Diameters in single mode optical fibres is discussed. The possible error causes are analyzed, with particular attention to systematic terms, and an evaluation of their effect is performed.

An interlaboratory comparison of measurements on six single-mode fibres of different designs, both conventional and dispersion modified, has been performed in the framework of COST 217 Project. This measurement campaign was aimed at the evaluation and optimisation of the various measurement techniques. The measured quantities included mode field di...

A new procedure for analysis of far-field data on single-mode fibers is proposed; it allows one to obtain mode field diameters with reproducibility of ±0.05 μm or better and to reconstruct reliably and unambiguously the refractive-index profile even for dispersion-modified fibers with moderate requirements on dynamic range of the measurements.

The role of the mode field diameter in the characterization of single-mode fibers is examined. The most relevant definitions of this parameter are reviewed, and a comparative analysis of methods for its measurement is performed. All the discussed measurement methods have reached a repeatability and reproducibility which are quite satisfying. Emphas...

An interlaboratory comparison of measurements on six single-mode fibres of different designs, both conventional and dispersion modified, has been performed in the framework of COST 217 Project. This measurement campaign was aimed at the evaluation and optimisation of the various measurement techniques. The measured quantities included mode field di...

An experimental characterization of bending sensitivity in single-mode fibres has been carried out by means of two distinct approaches. In the former the first measurement technique for the spot-size w// infinity , that describes both macro- and microbending losses, is proposed. In the second approach the microbending loss has been measured directl...

The determination of the sensitivity of a single-mode optical fibre to microbending and macrobending is of great importance. Two kinds of spot-size rule such a sensitivity: wn, the r.m.s. width of the near-field, and Woo the inverse of the transverse propagation constant in the cladding. While measurement techniques for wn are already known, this p...

A new and simple expression of microbending losses, obtained by a suitable modeling of the coupling coefficients, is proposed. Application to both conventional and dispersion optimized single-mode fibers shows agreement with the exact numerical analysis.

A new and powerful analysis of microbending in generic single-mode fibres is outlined. The calculation avoids cumbersome evaluations of the coupling coefficients and allows the derivation of a simple and better approximated expression for the microbending losses. More severe upper and lower bounds to the possible losses are also provided.

5th Eur. Conf. Optical Communication, ECOC '89. Göteborg, Sweden, 10 - 14 Sept. 1989, 223 - 226

IEE Proc. Part 3