High frequency microwave signal generation using dual-wavelength emission of cascaded DFB fiber lasers with wavelength spacing tunability

[EN] A dual wavelength fiber laser source based on two cascaded phase-shifted fiber Bragg gratings is presented The gratings are written in an erbium-doped fiber each configuring the cavity of a distributed feedback fiber laser The spacing between lasing modes is controlled dynamically by the use of piezoelectric actuators A continuous tuning range of 5-724 pm of the wavelength difference which is equivalent to a photodetected 072-92 GHz range is obtained Efficient generation from the L to the W microwave and millimeter bands has been achieved by heterodyne photodetection of the dual-wavelength optical signal (C) 2010 Elsevier BV All rights reserved

Ultra-Wideband Radio Signals Distribution in FTTH Networks

[EN] The use of an ultra-wideband (UWB) radio technique is proposed as a viable solution for the distribution of high-definition audio/video content in fiber-to-the-home (FTTH) networks. The approach suitability is demonstrated by the transmission of standards-based UWB signals at 1.25 Gb/s along different FTTH fiber links with 25 km up to 60 kin of standard single-mode fiber length in a laboratory experiment. Experimental results suggest that orthogonal frequency-division-multiplexed UWB signals exhibit better transmission performance in FFTH networks than impulse radio UWB signals.

All-fiber processing of terahertz-bandwidth signals based on cascaded tapered fibers

Tapered single-mode fibers are employed to perform dynamic pulse shaping in a bandwidth of several terahertz. The transfer function of cascaded biconical tapers is controlled by introducing a phase shift into one of them through mechanical stretching. It is a simple and low-cost technique with potential to process signals with bandwidths as large as those allocated by standard optical fiber while introducing little degradation. Femtosecond pulses are shaped to prove the concept. (C) 2013 Optical Society of America

Combined Analysis of OFDM-UWB Transmission in Hybrid Wireless-Optical Access Networks

[EN] The hybrid wireless-optical transmission of ultra-wideband signals employing orthogonal frequency-division multiplexing modulation (OFDM) ultra-wideband (UWB) as defined in the ECMA-368 standard is experimentally analyzed in this letter. The OFDM-UWB signals provide 400 Mb/s per user at optical distances from 5 to 50 km on standard single-mode fiber (SSMF). The analysis includes the wireless radiation from 0 to 3 m after optical transmission. The results indicate a maximum error-vector-magnitude degradation of 2.5 dB measured at 1.5-m radio after 50-km SSMF optical transmission for the first two UWB channels. This degradation translates to 1-m maximum wireless-reach penalty.

Joint Distribution of Polarization-Multiplexed UWB and WiMAX Radio in PON

[EN] In this paper, the feasibility of the joint distribution of ultra-wideband (UWB) and WIMAX wireless using polarization multiplexing as a coexistence technique is proposed and experimentally demonstrated within the framework of passive optical networks (PON). Four single- and orthogonal-polarization multiplexing schemes are studied targeting to reduce the mutual interference when UWB and WiMAX are distributed jointly through standard single-mode fiber (SSMF) without transmission impairments compensation techniques and amplification. Experimental results indicate successful transmission up to 25 km, in SSMF exceeding the range in typical PON deployments. The radio link penalty introduced…

Fully automatic simultaneous fiber grating amplitude and group delay characterization