Modelling and examination of 1550 nm wavelength passively mode locked a semiconductor laser

In this study, modelling and experimental study of a 1550 nm wavelength passively mode locked semiconductor laser has been carried out. Forward biased section of the passively mode locked semiconductor laser is called gain section while reverse biased section is called absorption section. In the modelling, variations of power-time, photon density-time, carrier density-time and pulse width of the passively mode locked semiconductor laser consisting of one or two gain sections and one absorption section are comparatively obtained. The semiconductor laser with two gain sections has higher power and shorter pulse width due to higher photon density and carrier density. Comparative results are obtained within the different lengths of the gain section of the passively mode locked semiconductor laser with two gain sections. In addition, the results are examined while the absorption section is located for both between the gain sections and in the far end. Power is observed to be higher when the absorber section is between the gain sections, because the absorption section causes narrowing of the pulse and loss of the peak. Comparative results of the power and pulse width are obtained for the different values of the current applied to the gain section and for the voltage applied to the absorption section. As the voltage applied to the absorption section increases, the power increases as the carriers lifetime decreases. Finally, the pulse width is calculated for the different lengths of the absorption section and the effect is shown on the power-time graph. It is observed that as the absorption section length increases, the power decreases because the loss and the pulse width increase.