A sensor for incoherent light based on the bi-periodic sensitivity characteristic of laser

The characteristics of bi-periodic sensitivity of semiconductor laser and its application in the incoherent light detection sensor are studied. From the simulation results, it can be found that the unmoving point of an optoelectronic time-delay feedback semiconductor laser shifts when there is external light injection, two unmoving points are conduced to show, and implies high instability dynamics existing in the system. So the external light injection will inevitably result in destructing the referent laser state condition and changing the state, thus the incoherent light intensity change can be monitored via detecting the referent state change. In this paper, a bi-periodic optical pulse is generated by the optoelectronic time-delay feedback semiconductor laser, and the bi-periodic laser system is used as a sensor for incoherent light detection. A bi-periodic state in the laser is a highly unstable nonlinear dynamic state, it is very sensitive to external conditions and influences. When a beam of external incoherent light enters into the bi-periodic laser sensor, it will inevitably lead to the destruction of the bi-periodic state condition and the state variation. A novel bi-periodic laser incoherent light detection sensor is proposed based on the above principle. By using this sensor, the injected incoherent light can be used as the sensor's recognition signal, and by detecting the change of the laser output behavior, the external incoherent light intensity can be measured. The simulation results show that the sensor has high ability to recognize the injected incoherent light and can measure it accurately. The results of the proposed sensor are quite useful for the research of new laser sensor and application of photoelectric detection technology