Crosstalk mitigation techniques in multi-wavelength networks comprising photonic integrated circuits

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Demonstration of long-reach PON using 10 Gb/s 3R burst-mode wavelength converter

Long-reach optical access networks promise significant cost savings. To merge existing metro and access networks to a single long-reach network, the long-reach technology has to address not only the power loss and fiber dispersion problems but also mismatch between two merged entities in terms of wavelengths and operational modes, especially during the transition period when support of legacy services is still required. In this letter, we demonstrate a long reach network employing a 10 Gb/s burst-mode O/E/O wavelength converter. The converter can simultaneously address the power loss, dispersion, and mismatch problems by a compact assembly. Two upstream wavelengths located in the 1310 nm and 1550 nm windows in the access section are converted to a DWDM wavelength of 1554.13 nm in the metro section. Error-free performance is achieved with a loud/soft ratio of 10 dB at a sensitivity of −27 dBm and the overhead for the burst-mode operation is as low as 0.512%

PROaccess : a passive-components-based reconfigurable WDM-TDM optical access network

The evolution of optical access networks have focused on improving their transmission capacity by increasing transmission bit rate per wavelength and number of wavelengths per fibre. However, the huge aggregated capacity is composed by separate bandwidth pools in which each wavelength channel is an independent pool. As a result, some wavelengths may be congested while others are underutilization. In order to allow the system capacity to be a single bandwidth pool, the wavelength reconfigurability is required in which an user can be relocated to another wavelength if the current wavelength is congested. Adding reconfigurable feature also adds complexity, hence CAPEX and OPEX to the networks. Therefore, networks operators up to now have been reluctant despite of benefits of the flexible bandwidth delivery. In this paper, we propose a cost-effective, reconfigurable optical access network by employing passive network components in the remote node and dual conventional optical transceivers in ONUs. The novel approach allows outside plant totally passive and ONUs without tunable filters and lasers. Despite of using only passive and non-tunable components, it still attains a superior flexibility. The architecture is demonstrated with the bidirectional transmission at 10 Gb/s symmetrically

DMT based multi-Gbit/s communication in indoor optical networks using R-SOA

After ‘fiber to the home’, fiber has reached in the room. To make such fiber based indoor networks cost and energy efficient, reflective modulators (like R-SOA and REAM) are core components which are also wavelength agile. They remove the need of laser sources at antenna access points for upstream signal. The baseband version of OFDM (i.e. DMT) along with bit-and power-loading algorithm can overcome the bandwidth limitation of R-SOA. In this paper, we have shown experimental results of multi-gb/s communication for upstream signal in indoor optical networks. DMT modulation scheme has been used to obtain throughput of 9 Gb/s with a 750MHz RSOA

Ultrahigh-capacity optical-wireless communication using 2D gratings for steering and decoding of DPSK signals

We demonstrate the use of a 2D-gratings beam-steering device also as a demodulator for multiple differentially-encoded optical-wireless signals. Using this novel concept, ~2bits/sec/Hz spectral-efficiency was achieved without any change in the system compared to on-off-keying

WDM monitoring technique using adaptive blind signal separation

We present a cost-effective method of monitoring the performance of wavelength-division-multiplexed (WDM) channels. The method is based on simple optical signal processing in combination with electronic signal processing. The photocurrent of a detected (multi-channel) optical signal is analysed using an adaptive blind signal separation method. A maximum data decorrelation criterion is used to separate the WDM channels. We show experimentally that four WDM channels can be reconstructed accurately by this numerical method

Optical generation of IR-UWB pulse based on weighted sum of modified doublets

We propose a relatively simple optical generation concept for impulse radio ultra wideband (IR-UWB) pulse over fiber transmission using a weighted sum of a modified doublet with its inverted and delayed version. The generated pulses not only fi4ly comply with the FCC spectral mask but also are highly power efficient in the available spectrum. We verified our approach using both simulation and experimental demonstration. The concept has a potential to be integrated with other optical functions on a compact optical chip, making it very suitable for wide UWB deployment for highspeed wireless access at low costfor in-building network applications