J.M. Fuster

True time-delay scheme for feeding optically controlled phased-array antennas using chirped-fiber gratings

A novel approach of true-time delay (TTD) optical feeder for phased-array antennas is proposed and demonstrated. A compact size continuously variable TTD is achieved by employing tunable lasers and one wide bandwidth chirped-fiber grating as dispersive element. A high-resolution performance (5.3 ps) is obtained for a 26-GHz phased-array antenna employing narrow tuning bandwidth lasers with a wavelength stability of 0.005 nm and a 4 nm bandwidth chirped grating.

On the use of fiber-induced self-phase modulation to reduce chromatic dispersion effects in microwave/millimeter-wave optical systems

In this letter, a novel approach to compensate for the dispersion-induced power penalty in externally modulated 1550-nm analog fiber-optic systems is presented. The principle is based on the use of fiber-induced self-phase modulation to generate a chirp distortion effect opposite to that induced by the chromatic dispersion. A significant reduction of chromatic dispersion effects is achieved, which results in augmenting the frequency-length product of the fiber-optic link. It is theoretically and experimentally shown how this dispersion compensation may be controlled by means of the optical power injected to the optical fiber.

Generalized study of dispersion-induced power penalty mitigation techniques in millimeter-wave fiber-optic links

The authors present a comprehensive analysis of the chromatic dispersion effects in harmonic upconverted millimeter-wave (mm-wave) fiber-optic links. The optical upconversion is performed through a photonic mixer based on a Mach-Zehnder electrooptical modulator. It is shown that by biasing the electrooptical modulator either at the maximum or at the minimum transmission bias points, the dispersion-induced power penalty effect on the upconverted signal may be sharply mitigated, which results in increasing the frequency-length product of the fiber-optic link. Experimental results are provided for the three different types of bias.

Fiber-optic microwave link employing optically amplified electrooptical upconverting receivers

An optically amplified Mach-Zender intensity modulator employed as upconverting receiver has been modeled and experimentally demonstrated for a 1.8-GHz fiber-optic link of 46.2-km standard single-mode fiber operating at 1.55 /spl mu/m. This receiving scheme overcomes dispersion-induced distortion as well as eases the use of linearized external modulators and high-frequency RF sources for optical feeding microwave and millimeter-wave radiocommunication systems.

Experimental reduction of chromatic dispersion effects in electro-optical up-converted millimeter-wave fiber-optic links

Summary form only given. Summary form only given. The rapid deployment of point-to-multipoint millimeter-wave radio systems for video distribution has resulted in much interest in optimizing millimeter-wave antenna remoting photonic links operating near 1550 nm. In these systems the performance is severely limited by the chromatic dispersion of standard optical fiber, which drastically limits the frequency-length product of fiber-optic links. Optical techniques such as self-heterodyne schemes and chirped fiber gratings have been proposed to combat the chromatic dispersion effects in millimeter-wave optical transmissions. On the other hand, several electro-optical upconverting schemes based on a single Mach-Zehnder modulator (MZ-EOM) have been proposed to alleviate the use of wideband linearized distributed feedback (DFB) lasers and wideband electronic devices. In addition, different biasing types in the MZ-EOM have been considered such as quadrature biasing (QB) and minimum transmission biasing (MTB). Furthermore, the impact of the different types of MZ-EOM biasing on the chromatic dispersion effects has been recently outlined showing the feasibility of mitigating the dispersion effects by biasing the upconverting MZ-EOM at MTB. In this paper, we demonstrate experimentally the significant reduction of the dispersion-induced carrier suppression effect on the up-converted signal by employing MTB in the MZ-EOM-based photonic upconverter.