Modeling and Performance Analysis of 1.55 µm Quantum Well Edge Emitting Laser Based on InGaN

Abstract

The advent of research work for longer wavelength 1.55 µm lasers, InGaN advances fast due to its compatible band gap energy and excellent properties. These lasers are well-suited and ideally matched with the existing fiber optic infrastructures as well as bandwidth of the modern ultra speed communication system with substantially tower attenuation, transmission losses, waveform degradation and dispersion penalty. In this thesis, a study is conducted on the design of 1.55 µm InGaN quantum well laser to investigate the effects on various design parameters for the better performance and to deduce an optimum laser structure. The study is separated into stages; it begins with an extensive review on the lasers in chronological order, followed by the development of the laser model with the analysis of band structure interpolation model as well as laser characterization Next, the thermal and equivalent circuit modeling is presented to investigate the temperature effect and electrical properties of the laser respectively. Careful analysis of the band profile by solving one-dimensional time independent Schrodinger and Poisson's equations using finite difference method is 4 demonstrated. The thermal and circuit-level laser modeling is also developed by solving the respective rate equations. Matlab as well as PSPICE simulation programming languages are employed for numerical analysis. The simulation and analysis results reveal the energy separation between different band and subbands for quantum well laser. It is observed that the electron density in conduction band is 1018cm-3 It is also found a better efficiency (59%), reduced threshold current density (1,1 19A/cm2), and bias voltage (1.1 volts), high optical gain (9,000 cm-1), moderate material gain (3,660 cm-1) and modal gain (45 cm-1). In addition, threshold current, 5.1 mA, output power, 5mW, and slope efficiency, 0.695W/A are obtained. Further understanding of the laser performance with different ambient temperatures the thermal effects has been analyzed. It is found that the threshold current has been increased to 5.5mA at the same ambient. Finally, the circuit level equivalent circuit demonstrates the electrical properties of the laser.