School of Physics, Georgia Institute of Technology, Atlanta, GA, United States, Georgia Tech-CNRS UMI-2958, Georgia Tech Lorraine, Metz, France, School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, United States, Georgia TechCNRS UMI-2958, Georgia Tech Lorraine, Metz, France, CNRS, Laboratory for Photonics and Nanostructures, Marcoussis, France, III-V Laboratory, A Joint Laboratory of Alcatel Lucent Bell Labs and Thales Research and Technology, CEA-LETI, Route de Nozay, Marcoussis, France

Laser diodes with optical feedback can exhibit periodic intensity oscillations at or near the relaxation-oscillation frequency. We demonstrate optoelectronic oscillators based on external-cavity semiconductor lasers in a periodic dynamical regime tunable over the entire $X$ -band. Moreover, unlike standard optoelectronic oscillators, we need not employ the time-dependent optical intensity incident on a photodiode to generate the microwave signal, but rather have the option of generating the electrical microwave signal directly as a voltage V(t) at the laser-diode injection terminals under constant current operation, no photodiode need be involved, thus circumventing optical-to-electrical conversion. We achieve a timing jitter of 10 ps and a quality factor of 2× 105 across the entire X -band, that ranges from 6.79 to 11.48 GHz. Tuning is achieved by varying the injection current J. © 1965-2012 IEEE.

microwave photonics, microwave source, nonlinear optics, Optoelectronic oscillator, semiconductor lasers dynamics

Microwaves, Nonlinear optics, Optoelectronic devices, Photodiodes, Semiconductor diodes, Semiconductor junctions, Semiconductor lasers, Timing jitter, Constant current operations, External cavity semiconductor lasers, Microwave Photonics, Microwave sources, Optical intensities, Optical-to-electrical conversion, Opto-electronic oscillator, Relaxation oscillation frequencies, Microwave oscillators