O. Legouezigou

Demonstration of RSOA-based remote modulation at 2.5 and 5 Gbit/s for WDM PON

This paper investigates the performance of a reflective semiconductor optical amplifier in a bidirectional wavelength-division multiplexed passive optical network at 2.5 and 5 Gbit/s over 20 and 15 dB link budget.

Separate Error-Free Transmission of Eight Channels at 10 Gb/s Using Comb Generation in a Quantum-Dash-Based Mode-Locked Laser

We report on comb generation at 1.55 mum using a mode-locked quantum-dash-based laser. A flat optical spectrum with a ~10-nm width consisting of eight 100-GHz-spaced channels is demonstrated. Separate error-free transmission of each channel is achieved at 10 Gb/s over 50-km-long single-mode fiber. Compared to an ideal external cavity continuous-wave laser, a penalty of only 1.5 dB is measured for each filtered channel. This is attributed to the higher relative intensity noise level of a filtered mode.

Standard-compliant jitter transfer function of all-optical clock recovery at 40 GHz based on a quantum-dot self-pulsating semiconductor laser

This letter reports on all-optical clock recovery over 40-Gb/s signal using a quantum-dot (QD)-based self-pulsating (SP) laser. In particular, the jitter transfer function from the input signal to the recovered clock is measured for the first time. We clearly demonstrate that, thanks to the narrow spectral linewidth of the free-running SP signal, the QD-based laser allows the suppression of high frequency jitter, and the cutoff frequency is exactly that required by the ITU-T recommendation G825.1 at 40 GHz

Polarization-Insensitive Low Timing Jitter and Highly Optical Noise Tolerant All-Optical 40-GHz Clock Recovery Using a Bulk and a Quantum-Dots-Based Self-Pulsating Laser Cascade

We report on the experimental assessment of an all-optical clock-recovery scheme at 40-Gb/s cascading a polarization-insensitive bulk-based self-pulsating (SP) laser and a high spectral purity quantum-dots-based SP laser. It is demonstrated experimentally that such a clock-recovery scheme is polarization insensitive, efficient in the jitter filtering, and tolerant for an input optical signal-to-noise ratio (OSNR) as low as 15 dB/0.1 nm. It is shown theoretically that the jitter-filtering function of the cascade is the product of the transfer functions of both lasers. The contributions of the phase noise of these two lasers to the final jitter are also identified and quantified. The influence of the degradation of the OSNR to the total timing jitter is also analyzed. The approach proposed in this paper offers the real opportunity to realize an all-optical clock recovery with a performance compatible for system applications

Error-free transmission of 8 WDM channels at 10 Gbit/s using comb generation in a quantum dash based mode-locked laser

Error-free transmission over 50 km single mode fiber of 8 WDM ITU channels with 100 GHz channel spacing is demonstrated at 10 Gbit/s by using comb generation in a quantum dash mode-locked laser.

Enhanced gain measurement at mode singularities in InP-based photonic crystal waveguides

We present a method of direct measurement of spectral gain and corresponding data in photonic crystal waveguides defined in heterostructures on InP substrates. The method makes use of two photopumping beams, one for gain generation, the other for amplification probing. The results show a clear enhancement of gain at spectral regions of low-group velocity, namely at the edges of the so-called mini-stopband of a three-missing rows wide photonic crystal waveguide.

Discontinuous wavelength super-refraction in photonic crystal superprism

Experimental results on wavelength-dependent angular dispersion in InGaAsP triangular lattice planar photonic crystals are presented. An abrupt variation of the angular dispersion is observed for TM-polarized waves whose frequencies are comprised between those of the fourth and sixth allowed bands. According to the crystal period, the measured angle of refraction is found to either decrease or increase by 30 degrees within a wavelength range smaller than 30 nm. Experimental results are reproduced well from 2D finite difference time domain calculations. The observed phenomena are interpreted from the coupling of the incident light to different modes of the photonic crystal that travel with different group velocities and propagate in different directions within the crystal. Mode dispersion curves and mode patterns are calculated along with isofrequency curves to support this explanation. The observed discontinuous wavelength super-refraction opens a new approach to the application of superprisms.

Quantum dots semiconductor optical amplifier with a-3dB bandwidth of up to 120 nm in semi-cooled operation

More than 120 nm of -3 dB optical bandwidth, together with 10 dB of internal gain at 50°C, are demonstrated and explained with specially designed quantum dot semiconductor optical amplifiers.

Low confinement factor quantum dash (QD) mode-locked Fabry-Perot (FP) laser diode for tunable pulse generation

Electrical spectrum line-width is reduced in mode-locked FP 1.55 μm-QD laser diode through optical confinement factor optimization. From optimized structures, we obtained nearly Fourier-transform limited pulses at 10 GHz, with an averaged width of 8 ps over 10 nm.

Impact of Lithographic Grid Irregularity Assessed on Photonic Crystal Device Selectivity

The gridding irregularities of electron beam lithography may deterministically disorder photonic crystals (PhC). Their practical impact is addressed on a PhC wavelength selective device using a large grid size of 8 nm. The device operation, based on confined resonances and propagation mini-stopbands in a multimode waveguide, is deterministically blurred. Scattering length scales are correspondingly discussed. Strategies for higher throughput lithography are proposed accordingly