Performance analysis of VCSEL using finite difference time domain method

Vertical Cavity Surface Emitting Laser (VCSEL) with significantly diverse structures has evolved with time for a different type of applications. A number of researchers used Finite Element Method (FEM) solver for computation of optical resonance modes in VCSEL but this method has a limitation of accuracy because it uses an approximate solution of partial differential equationsand integral equations. Furthermore, FEM is based either on eliminating the time derivatives completely or by rendering the partial differential equations into an equivalent ordinary differential equations. In this research work, we have used Finite Difference Time Domain (FDTD) method which elaborates the fine features of VCSEL and the accuracy of the VCSEL results got improved.The proposed approach is also beneficial for calculating reflectance for multiple wavelengths of light per simulation which is the major advantage over FEM. In this research paper, a new VCSEL structure is modeled and also numerically investigated by using proposed FDTD method. A complete analysis of VCSEL light emission, its electric field and Poynting vector are also evaluated at different points of light in thesecond window of optical communication. A rigorous evaluation in terms of spectrum analysis, transmission analysis and farfield projection analysis is done for wavelength ranging from 1310 nm to 1350 nm. Results show that the maximum power of 0.81 W is obtained at a wavelength of 1320 nm with maximum peak voltage of 1.4 V/m and 0.006 W/m2 Poynting vector.