Effect of Partial Optically Filtered Optoelectronic Feedback on Laser Diode Chaotic Emission

This experimental study investigates a laser diode dynamic with a large external cavity under a novel technique. Optoelectronic feedback contributes to the optically filtered feedback subject to strength variation by a sensor. This temperature sensor has selected Bragg wavelengths that satisfy wide filtering. This mixing between sensors and communications is a very challenging topic. Two FBGs have experimented; their types differ in FBG active region number, such that they have three and four regions. Results indicate the achievement of various kinds of chaotic signals and spikes. These chaotic signals include strange attractors and large enough chaotic bandwidths. The measured FWHM is changed periodically between two values; 0.25-0.7 kHz versus the bias voltage. This variation manner is changed as a function of the sensor region number. This means that the effect of optical filtering gives a direct response to chaotic laser emission. In the same situation, when optoelectronic feedback is tuned, laser threshold reduction is also observed to indicate good alignment. The two later observations provide evidence for the interplay between these two types of feedback in such a system for applying high-security optical communication and laser networks.