Limited chaotic dynamics in isolated laser diode by fiber loop mirror

In this work, experimental study for the chaotic dynamics of a quantum well semiconductor laser (SL) (1310 nm wavelength) with anoptical loop mirror is investigated. The spikesareintroduced by configuring this external cavity type. Making one arm from this cavity be attenuated led to retardation for it. Disturbance in longitudinal lasing mode resulted in chaotic spectrum. Bandwidth for this signal is very limited and changeable under the attenuation ratio. In comparison to pure optical feedback, the achieved signal is lower and evolved from kHz band (in 4.3 v bias voltage) to MHz band (with higher voltages i.e., 4.7 and 4.8 volt). The first range included 300% higher amplitudes for the lasing modes, while the later was equivalent to the random like signal amplitudes. Such a range can be employed for laser wavelength fine tuning applications with the benefit of not disturbing the laser medium. This results opens the door for mixing resulted signal with another oneprimary subjects to pure optical feedback.