Steevy Cordette

Nonlinear Pulse Reshaping With Highly Birefringent Photonic Crystal Fiber for OCDMA Receivers

We combine an erbium-doped fiber amplifier with a short segment of highly birefringent photonic crystal fiber to generate a nonlinear transfer function suitable for optical transmission systems based on optical code-division multiple-access (OCDMA). Such a functional element based on spectral broadening followed by an off-center narrow optical filtering provides an effective suppression of spurious signals such as multiple-access interferences in OCDMA receivers and can reduce the pulses amplitude jitter.

Spectral slicing of a supercontinuum source for WDM/DS-OCDMA application

WDM and optical CDMA are leading contenders to easily upgrade access network performances in terms of multiple access technique. Both methods can be used at once, using a single multiwavelength optical source. We show, numerically and experimentally, that spectral slicing of a 10-GHz pulse train broadened to a supercontinuum yields pulses suitable for use in a direct sequence optical CDMA system. Simulations with optical CDMA encoders and decoders based on superstructured fiber Bragg gratings indicate good performance can be expected.

A novel ring architecture of multiple optical private networks over EPON using OCDMA technique

We propose a novel ring architecture to install multiple optical private networks (PNs) on EPON infrastructure. The PNs are demonstrated to be independent of OLT which does not add any supplement traffic management into OLT. We experimentally demonstrate two active PNs communications using OCDMA technique in which ONUs within PN are interconnected and sharing the same codeword.

Optical CDMA enhanced by nonlinear optics

Intended for the next generation of optical access networks, OCDMA is of great interest to meet the demand of increasing the number of users per access fiber, especially as spectral phase coding increases its performance in the optical domain. This, however, requires handling broad spectra and short pulses, which are best dealt with using opto-electronic or all-optical devices instead of slower electronics. Among others, we demonstrate spectral-phase-coded OCDMA using a fiber-based saturable absorber as thresholding in the receiver.

Enabling internetworking among ONUs in EPON using OCDMA technique

A network architecture to interconnect ONUs independent of optical line terminal (OLT) on EPON is proposed. By inserting a fiber Bragg grating (FBG) reflector before the PON star coupler, internetworking communication is established without adding extra traffic management to OLT. Thus, the internetworking data is reflected back to the ONUs, while EPON data streams pass freely through this reflector. The sparser and longer extended congruent codes (EQC) with good correlation properties are used as optical CDMA en/decoders in this system. Finally, we test the BER performance of this system with two active private networks (PNs) communications using OCDMA technique in which ONUs within a PN are interconnected sharing the same code word.