Simulation and analysis of dependence of threshold current and gain of λ/4 shifted DFB laser through transfer matrix.

This paper presents temperature dependence of the refractive index, coupling factor, and threshold current in a distributed feedback (DFB) semiconductor laser with different grating amplitudes. It is shown that with increasing the temperature, the threshold current increases and the coupling factor decreases. In addition, the performance of DFB semiconductor lasers was theoretically investigated through deformed concave grating. According to calculation, symmetrical grating structures have the maximum coupling factor, which increases with the period of grating grooves. Finally, concave grating would improve the output power. Analysis in this research was done by simultaneously solving both the coupled wave and rate equations using the transfer matrix. [ABSTRACT FROM AUTHOR]