Laurent Bramerie

170 GBit/s transmission in an erbium-doped waveguide amplifier on silicon

Signal transmission experiments were performed at 170 Gbit/s in an integrated Al(2)O(3):Er(3+) waveguide amplifier to investigate its potential application in high-speed photonic integrated circuits. Net internal gain of up to 11 dB was measured for a continuous-wave 1532 nm signal under 1480 nm pumping, with a threshold pump power of 4 mW. A differential group delay of 2 ps between the TE and TM fundamental modes of the 5.7-cm-long amplifier was measured. When selecting a single polarization open eye diagrams and bit error rates equal to those of the transmission system without the amplifier were observed for a 1550 nm signal encoded with a 170 Gbit/s return-to-zero pseudo-random 2(7)-1 bit sequence.

Noise reduction in 2R-regeneration technique utilizing self-phase modulation and filtering

We numerically investigate the 2R-regeneration technique utilizing self-phase modulation and off-center filtering. Our numerical simulations take into account the incoherent nature of noise through its spectral representation. This approach allows to evaluate a Q-factor improvement of 2 dB for this regenerator. Furthermore, our study points out the role of both the input and the output filter of this regenerator. We show that the input filter must be suitably chosen in order to obtain the best Q-factor improvement. The output filter must also be suitably chosen in order to preserve the modulation format.

Efficient four-wave mixing in an ultra-highly nonlinear suspended-core chalcogenide As38Se62 fiber

We report a chalcogenide suspended-core fiber with ultra-high nonlinearity and low attenuation loss. The glass composition is As(38)Se(62).With a core diameter as small as 1.13 µm, a record Kerr nonlinearity of 46,000 W(-1) km(-1) is demonstrated with attenuation loss of 0.9 dB/m. Four-wave mixing is experimented by using a 1m-long chalcogenide fiber for 10 GHz and 42.7 GHz signals. Four-wave mixing efficiencies of -5.6 dB at 10 GHz and -17.5 dB at 42.7 GHz are obtained. We also observed higher orders of four-wave mixing for both repetition rates.

Quantum-Dash Mode-Locked Laser as a Source for 56-Gb/s DQPSK Modulation in WDM Multicast Applications

We investigate wavelength tunable 56-Gb/s differential quaternary phase-shift keying (DQPSK) systems using comb generation in a quantum-dash mode-locked laser for wavelength-division-multiple access (WDM)-based broadcast application. We present relative intensity noise and bit-error-rate measurements for each mode. We demonstrate error-free operation over nine WDM channels with 100-GHz spacing.

Multi-Data-Rate System Performance of a 40-GHz All-Optical Clock Recovery Based on a Quantum-Dot Fabry–PÉrot Laser

Bit-error-rate assessment of a multi-rate all-optical clock recovery (OCR) based on a narrow linewidth mode-locked quantum-dot (QD) Fabry-Perot laser is presented in this letter. OCR has been achieved without external feedback. We use a QD Fabry-Perot semiconductor laser designed for 40-GHz clock extraction. We then present OCR performance with 40-, 80-, and 160-Gb/s input data signal and demonstrate that clock recovery has been obtained thanks to subharmonic locking process. Results are presented through penalty measurement using an original characterization based on recovered clock remodulation with electrical data from the transmitter. This technique allows us to evaluate the quality of the recovered clock.

Ultrafast all-optical switching and error-free 10 Gbit/s wavelength conversion in hybrid InP-silicon on insulator nanocavities using surface quantum wells

Ultrafast switching with low energies is demonstrated using InP photonic crystal nanocavities embedding InGaAs surface quantum wells heterogeneously integrated to a silicon on insulator waveguide circuitry. Thanks to the engineered enhancement of surface non radiative recombination of carriers, switching time is obtained to be as fast as 10 ps. These hybrid nanostructures are shown to be capable of achieving systems level performance by demonstrating error free wavelength conversion at 10 Gbit/s with 6 mW switching powers.

All-optical regeneration techniques

Basic principles of all-optical signal regeneration are presented, and main state-of-art techniques are reviewed. Optical fiber and semiconductor based devices are addressed, and some recently reported 2R and 3R signal regeneration experiments are discussed.RésuméLes principes de base de la régénération tout-optique de signaux de télécommunication sont présentés, ainsi qu’une revue des principales techniques actuellement étudiées, concernant les dispositifs à fibre et à semi-conducteurs. Quelques récentes expériences de régénération 2R et 3R sont également considérées.

Analysis of thermal limitations in high-speed microcavity saturable absorber all-optical switching gates

The limitations owing to device heating and thermo-optic effects in high-speed quantum-well microcavity saturable absorber devices are investigated both theoretically and experimentally. A simplified theoretical description of the device electronic, thermal, and optical properties is developed and applied to the modeling of the device switching characteristics for reamplification + reshaping step (2R) all-optical regeneration. These predictions are compared to nonlinear optical measurements performed with switching pulses of fixed duration and variable repetition rate on two devices with significantly different thermal properties. It is shown that proper optimization of the device thermal properties is crucial to avoid the degradation of device performance at high bit rate. It is also shown that the negative effects of optically induced heating on the switching contrast may be compensated to some extent by operating the device on the long wavelength side of the microcavity resonance

Cascadability assessment of a 2R regenerator based on a saturable absorber and a semiconductor optical amplifier in a path switchable recirculating loop

We assess a new 2R regenerator based on a microcavity saturable absorber and a semiconductor optical amplifier. Cascadability is demonstrated and the impact of regeneration span is studied in a 10-Gb/s two-path recirculating loop. A wavelength study demonstrates the tunability of the device over 13 nm

Bidirectional 2.5-Gb/s WDM-PON Using FP-LDs Wavelength-Locked by a Multiple-Wavelength Seeding Source Based on a Mode-Locked Laser

We experimentally investigate the operation of a cost-effective wavelength-division-multiplexed passive optical network (WDM-PON) based on wavelength-locked Fabry-Pérot laser diodes (FP-LDs). A single quantum-dash passively mode-locked laser (QD-MLL) is combined with an arrayed waveguide grating in WDM-PON architecture to provide a low-noise, coherent multiwavelength seeding source to injection-lock the FP-LDs for both downstream and upstream. The results show that the QD-MLL-injected FP-LD has the same performance when compared to the case of injection-locking by a low-noise external cavity laser. Error-free bidirectional transmission over 25 km for 16 channels with 42.7-GHz channel spacing is demonstrated at 2.5 Gb/s in the C -band and an optical budget higher than 30 dB is reached.