We present here a 1.55 μm single mode Vertical-Cavity Surface-Emitting Laser (VCSEL) based low phasenoise
ring optoelectronic (OEO) oscillator operating at 2.49 GHz for aerospace, avionics and embedded systems
applications. Experiments using optical fibers of different lengths have been carried out to obtain optimal results.
A phase-noise measurement of -107 dBc/Hz at an offset of 10 kHz from the carrier is obtained. A 3-dB linewidth
of 16 Hz for this oscillator signal has been measured. An analysis of lateral mode spacing or Free Spectral Range
(FSR) as a function of fiber length has been carried out. A parametric comparison with DFB Laser-based and
multimode VCSEL-based opto-electronic oscillators is also presented.
For a long time, only a small wavelength range of Vertical-Cavity Surface-Emitting Lasers (VCSEL) was available.
The current evolution in process technology allows the fabrication of long wavelength VCSEL that is
interesting for Telecom systems because they offer a higher integration level than the existing optical sources
at lower costs since they are fabricated in arrays. We propose to focus our investigation on the behavior of
singlemode 1.55μm VCSEL. We aim at precisely knowing their spectral properties under direct modulation.
We present a study about the linewidth measurement and the linewidth enhancement factor, also called the
Henry - or the alpha - factor. Many studies have been reported but only a few of them are really efficient. Two
different set-ups are presented here to extract alpha factor. The first one uses an interferometer based on the
heterodyne technique and the second uses the dispersive properties of an optical fiber. We compare both results
and discuss about each set-up.