Mohamed Essghair Chaibi

The Dual-Electroabsorption Modulated Laser, a Flexible Solution for Amplified and Dispersion Uncompensated Networks Over Standard Fiber

We propose here a monolithically integrated dual RF access electroabsorption-modulated laser called D-EML for the generation of optical single-sideband signal for both nonreturn to zero and orthogonal frequency division multiplexing formats. The benefits of optical single-sideband over double sideband in terms of resilience against chromatic dispersion effects are presented for high-bit rate intensity modulation/direct detection transmissions over standard single mode fiber in the C-band. Both simulation and experimentation exhibit transmission distance enhancement in the case of dual modulation of the D-EML, i.e., in optical single-sideband configuration, making this optical source an interesting solution because of its low-cost, low-size, and reasonable-power consumption.

Dispersion Compensation-Free IM/DD SSB-OFDM Transmission at 11.11 Gb/s Over 200 km SSMF Using Dual EML

We report on a novel optical single sideband-orthogonal frequency division multiplexing system for access and metro networks based on a single, low cost dual electro-absorption modulated laser. The experimental results successfully demonstrate transmissions at 11.11 Gb/s over 200 km uncompensated standard single mode fiber through intensity modulation and direct detection.

Generation of SSB optical signals with dual-EML modulated with wideband OFDM

The generation of optical SSB signals by a Dual-EML is generalized for wideband modulating signals. The feasibility of the proposed technique is demonstrated by transmitting 5.3 GHz baseband OFDM signal in an optical SSB context.

Time Resolved Chirp Measurement Based on a Polarization-Maintaining Fiber

In high-speed optical networks, quantifying both the intensity and the frequency behaviors of optical signals has become a crucial task to evaluate transmission performance. In this letter, we report on a new technique to characterize optical signals. It is based on low-cost components and its operating mode is easy to provide accurate and fast measurements. The proposed technique is experimentally validated with signals whose characteristics are known. It is also tested with different optical transmitters.

Advanced modulation format using silicon modulators in the O-band

This paper review our recent work on silicon modulators based on free carrier concentration, working in the O-band of optical communications (1260 nm - 1360 nm) for short distance applications. 25 Gbit/s OOK modulation is obtained using a driving voltage of 3.3 Vpp , and QPSK dual-drive Mach-Zehnder modulator (DDMZM) operating in the O-band is demonstrated for the first time.

Optical spectral reshaping for directly modulated 4-pulse amplitude modulation signals

The tremendous traffic growth in intra/inter-datacenters requires low-cost high-speed integrated solutions [1]. To enable a significantly reduced footprint directly modulated lasers (DMLs) have been proposed instead of large external modulators. However, it is challenging to use DMLs due to their low dispersion tolerance and limited achievable extinction ratio (ER). A promising solution to this problem is optical spectral reshaping (OSR) since it is possible to increase the dispersion tolerance as well as to enhance the achievable ER for both on-of-keying [2] and 4-pulse amplitude modulation (PAM) [3] signals. However, moving to 4-PAM,many of the impressive demonstrations reported so far rely heavily on off-line digital signal processing (DSP), which increases latency, power consumption and cost. In this talk, we report on (i) a detailed numerical analysis on the complex transfer function of the optical filter for optical spectral reshaping in case of pulse amplitude modulation and(ii) an experimental demonstration of real-time dispersion-uncompensated transmission of 10-GBd and 14-GBd 4-PAM signals up to 10- and 26-km SSMF. This is achieved by combining a commercial 10-Gb/s DML with optical spectral shaping, thus removing the need for any complex off-line DSP and improving dispersion tolerance. These achievements are enabled by OSR based on a passive microring resonator fabricated on the SOI platform [4]. Significant improvement in receiver sensitivities was observed for both a 10-GBd signal after 10-km SSMF transmission and 14-GBd with no penalty after 26-km SSMF transmission.

1.5-μm Directly modulated transmission over 66 km of SSMF with an integrated hybrid III-V/SOI DFB laser

A hybrid III-V/SOI directly modulated DFB laser operating at 1.5 μο is fabricated, showing a side mode suppression ratio above 50 dB and a 3-dB bandwidth of 12 GHz. Error-free transmission (BER<10⁻⁹) at 10 Gb/s over 66-km SSMF is demonstrated without dispersion compensation and FEC.

Mitigation of mode partition noise in quantum-dash Fabry-Perot mode-locked lasers using Manchester encoding and balanced detection

We propose the use of Manchester encoding in conjunction with balanced detection to overcome the mode partition noise (MPN) limit of quantum-dash Fabry-Perot mode-locked lasers (QD-MLLs) used as multi-wavelength sources in short-reach applications. The proposed approach is demonstrated for a 10-mode laser, each carrying a 10-Gb/s signal. We show that bit-error-rate floors as high as 10-4 when traditional non-return-to-zero (NRZ) modulation is employed with a single-ended detection scheme can be pushed below 10-9 thanks to the introduction of Manchester encoding together with balanced detection. The benefit of the scheme could be attributed to the spectral shift of the Manchester spectrum, resulting in a smaller overlap with the high-relative intensity noise (RIN) region present at low frequencies, and the use of balanced detection. We clarify the origin of the performance improvement through comparisons of single-ended and balanced detection and the use of a RIN emulation technique. We unambiguously show that the use of balanced detection plays the leading role in MPN mitigation enabled by Manchester modulation.

Dispersion uncompensated IM/DD transmissions of 12GHz-wide multi-band OFDM over 100km with a D-EML

Generation of optical SSB signals by a D-EML is extended to its whole bandwidth. In an SSB context, 12GHz multi-band OFDM signal is transmitted through 100km intensity modulation/direct detection dispersive channel without frequency fading.

Up to 16 Gb/s CAP16 modulation over 100 km IM/DD dispersion uncompensated transmission using Dual-EML

Transmissions at 16 Gb/s of 16-QAM CAP signals over 100 km IM/DD dispersive channel are reported. They are performed in an optical SSB context generated with an integrated Dual-EML.