An improved model for computing the reflectivity of a AlAs/GaAs based distributed bragg reflector and vertical cavity surface emitting laser

Abstract

In this paper, reflectivity of a Distributed Bragg Reflector (DBR) has been computed by considering the effects of changes of wavelength on the changes of the refractive index of the materials of DBR layers. The intrinsic losses of the materials have been included in the computation of the reflectivity of the DBR. It has been found that the effect of change of the wavelength on the refractive index of the DBR materials reduces the Full Width Half Maxima (FWHM) of the stop band significantly which is expected to improve the laser characteristics. If the FWHM is reduced, the thickness of the active layer of a VCSEL can also be reduced which will further reduce the threshold current of the device. It has been found that the intrinsic losses of the materials have a significant effect on the reflectivity of a DBR. It has also been found that peak reflectivity of a 20 pair AlAs/GaAs DBR reduces by 0.2% after including the intrinsic losses (with a value of the intrinsic losses α = 10 cm −1 ).

Optical Quality of InAs/InP Quantum Dots on Distributed Bragg Reflector Emitting at 3rd Telecom Window Grown by Molecular Beam Epitaxy

“…The numerical box has dimensions of 4 μm width and 6.75 μm height to avoid artificial photonic confinement and modes. To obtain more realistic input parameters for the thicknesses of the DBR layers, low temperature reflectivity spectra measured on the planar sample and simulated within transfer matrix approach [ 94 , 95 , 96 ] (not shown here) were compared. The actual thicknesses of 124.8 nm and 111.3 nm for InP and InAlGaAs, respectively, were determined.…”

Number of p-type distributed Bragg reflectors effects on gallium nitride (GaN)-based vertical cavity surface emitting laser performance

“…(1) the low and high refractive indexes of the two layers in DBR, respectively. The DBRs designing criteria are related to maximum optical reflectivity, thermal and electrical conductivity, material index contrast and optical absorption (Saha and Islam 2009). The analysis of DBR in VCSEL design is critical due to its strong reflectivity effect on all laser fundamental properties (Saha and Islam 2009); therefore, the attention paid to the optimized distributed Bragg reflectors, which is very important in VCSEL design (Piprek, 2005).…”

“…The DBRs designing criteria are related to maximum optical reflectivity, thermal and electrical conductivity, material index contrast and optical absorption (Saha and Islam 2009). The analysis of DBR in VCSEL design is critical due to its strong reflectivity effect on all laser fundamental properties (Saha and Islam 2009); therefore, the attention paid to the optimized distributed Bragg reflectors, which is very important in VCSEL design (Piprek, 2005). The optimization of the DBR structure is fundamentally important to increase the performance of optical systems based on the VCSEL technology (Song et al, 2000;Jasim et al, 2011).…”