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[EN] Microwave photonics provides attractive solutions for millimeter wave (mmW) signal generation. In this paper, we demonstrate photonically generated multiple mmW signals transmission over a wavelength division multiplexed (WDM) hybrid optical network based on optical fiber and free-space optics (FSO) links. The experimental results demonstrate the generation and reconfigurable signal distribution from a central office to base stations in the frequency range 14 40 GHz with phase noise levels below 87 dBc/Hz. Moreover, 10 Gb/s data transmission has been demonstrated over photonically generated 40 GHz mmW signal. We show that FSO technology provides a possible solution for mmW fronthaul in 5th generation networks to extend the optical access network providing increased wireless accessibility and maintaining transmission capacity.

[EN] Microwave photonics provides attractive solutions for millimeter wave (mmW) signal generation. In this paper, we demonstrate photonically generated multiple mmW signals transmission over a wavelength division multiplexed (WDM) hybrid optical network based on optical fiber and free-space optics (FSO) links. The experimental results demonstrate the generation and reconfigurable signal distribution from a central office to base stations in the frequency range 14 40 GHz with phase noise levels below 87 dBc/Hz. Moreover, 10 Gb/s data transmission has been demonstrated over photonically generated 40 GHz mmW signal. We show that FSO technology provides a possible solution for mmW fronthaul in 5th generation networks to extend the optical access network providing increased wireless accessibility and maintaining transmission capacity.

A general model of analog microwave photonic links employing cascaded amplitude and phase external modulation is theoretically derived. Chromatic dispersion is also included in the model showing a different dispersion induced attenuation response in comparison to pure phase or amplitude modulation. Thus, hybrid modulation can be used to increase the bandwidth of radio over fiber links without the need of single-sideband modulation or dispersion compensation. Experimental results agreeing with the derived theory are also provided. (C) 2011 Elsevier B.V. All rights reserved.

A general model of analog microwave photonic links employing cascaded amplitude and phase external modulation is theoretically derived. Chromatic dispersion is also included in the model showing a different dispersion induced attenuation response in comparison to pure phase or amplitude modulation. Thus, hybrid modulation can be used to increase the bandwidth of radio over fiber links without the need of single-sideband modulation or dispersion compensation. Experimental results agreeing with the derived theory are also provided. (C) 2011 Elsevier B.V. All rights reserved.

This report focuses on the fabrication aspects of Electroabsorption Modulator (EAM) devices developed by the University of California at San Diego (UCSD). Air Force Research Laboratory (AFRL) SNDP personnel learned the processes directly at UCSD with the primary goal of transitioning the process to AFRL/SNDP. EAMs were designed to operate at 1550 nm using Indium Phosphide (InP) technology with semi-insulating wafers purchased from Tee Wel (Taiwan). Most of the process uses negative photoresist and is an 8-step mask procedure. The final metal coating is most critical to making robust n- and p- contacts. Without good metallization, wire bonding into a package fails. This report acts as a recipe aid to EAM device fabrication. Various times, levels, temperature, etc., quoted in this report were determined after careful calibration studies for each processing step and should only be used as guide values. Parameters change as materials age and machines change., The original document contains color images.

Photonic Systems, Inc. pursued the goal stated in the RF Lightwave Integrate Circuits' (RFLIC's) BAA ("...achieving a Vpi in the range of 0.1 to 0.5 Volts [to enable a link having] zero RF insertion loss with 1 - 10 mW of optical power available from conventional laser diode sources") on two parallel development paths. Collaborating with Sarnoff Corporation, Photonic Systems developed a Bipolar Cascade Laser that achieved a slope efficiency of 0.5 W/A by forcing the link's input RF signal to feed a series-connected succession of multiple laser junctions whose optical outputs are collected in parallel to illuminate the link's single photodetector. Additionally, Photonic Systems developed a Broad Bandwidth Resonant Modulator, in which two low-loss optical resonators act as a lever to reduce the effective Vpi by 25% for a Vpi=2.7V of the interferometric optical intensity modulator process relative to the Vpi of the optical phase modulator embedded within the two resonators., DARPA Order No. AOJ811. The original document contains color images.