The Effect of Doping Change in Distributed Bragg Reflector (DBR) Layers on the Operation at Different Temperatures of an InP-Based Vertical Cavity Surface Emitting Laser (VCSEL)
A. Ghadimi and M. Ahmadzadeh
The effect of the changing doping concentration on performance of vertical cavity surface emitting laser at different temperatures was investigated. The lasing wavelength is 1.55 μm. The doping concentration was changed from 1016 to 1018 at each doping level; the performance of a multi-quantum-well (MQW) vertical cavity surface emitting laser (VCSEL) was evaluated at temperatures between 273 and 350 K. This article presents the dependency of some VCSEL specifications like threshold current, gain, maximum radiation power, and resonance wavelength to the doping concentration of distributed Bragg reflector (DBR) layers at different temperatures. The results show that when doping concentration decreases at constant temperature, optical gain decreases. The highest gain is achieved at 350 K and 4 × 1017 doping concentration. At constant doping concentration, threshold current increases as temperature increases. The worst case for threshold current was observed, at 1018 doping concentration in the DBR layers at 350 K. It was observed that in a particular doping concentration the resonance wavelength increased as the temperature enhanced and photon energy shows a downward shift.
Keywords: Vertical cavity surface emitting laser (VCSEL), distributed Bragg reflector (DBR), multi-quantum-well (MQW), doping concentration, resonance wavelength, threshold current, radiation power, temperature, finite element method (FEM)