Modeling of Active Layer and Injection-locking Characteristics in Polarized and Unpolarized Fabry-Perot Laser Diodes

Abstract

Modeling of Active Layer and Injection-locking Characteristics inPolarized and Unpolarized Fabry-Perot Laser Diodes (Received January 6, 2012; Revised manuscript February 14, 2012; Accepted February 14, 2012) In this paper, injection-locking characteristics versus active layer structures in Fabry-Perot laser diodes (FP-LD) are compared. TE and TM gain spectra and peak gains versus carrier density in polarized and unpolarized multiple quantum well structures and in an unpolarized bulk structure are calculated. The calculated gain parameters are applied to a time-domain large-signal model to simulate the injection-locking characteristics. The results show that RIN in unpolarized FD-LDs is about 3 dB lower than that in a polarized FP-LD and that the eye characteristics of the unpolarized FP-LD are much better than those of the polarized FP-LD.

Epitaxial Structure Optimization for High Brightness InGaN Light Emitting Diodes by Using a Self-consistent Finite Element Method

“…The quasi-Fermi levels and electrostatic potential are resolved iteratively until the total current density converges within specified tolerance [5][6][7][8][9]. Fig.…”

“…  in the last term of equation (12) indicates the spontaneous emission rate between the conduction and the valence subbands, and it is directly calculated from the multi-band Hamiltonian equations including the strain and piezoelectric effects [5][6][7][8][9]. However, the analysis of the actual LEDs is not easy due to many unknown physical parameters such as the dislocation density, piezoelectric parameters, and deformation potential parameters.…”

“…  and   denote the recombination and generation rates for electrons and   and   for the holes in each layer. They include the Auger and SRH recombination processes [3] and spontaneous emission between the conduction band and valence band [7][8][9]. Basic semiconductor physics states that the drift and diffusion current densities can be expressed in terms of the quasi-Fermi levels as follows [10]:…”

“…In this paper, a self-consistent light-current-voltage solver which takes all the major nonradiative recombination processes and current spillover into account has been utilized to investigate the power efficiency of LEDs with various epilayer structures at high injection levels. In the simulator, the radiative recombination rate is automatically estimated from the multiband Hamiltonian for the wurtzite crystals [5][6][7][8][9]. The non-radiative recombination processes such as Auger and Shockley-Read-Hall recombination processes have also been incorporated in the ambipolar current continuity equations [3,7].…”