Photonic crystal enhanced lasers

• Main Author: Oon, KaiXiang.
• Other Authors: Zhang Dao Hua
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics
• Online Access: http://hdl.handle.net/10356/53355
• Institution: Nanyang Technological University

This project studied the research work of VCSEL and also the active region of VCSEL. The aim of this project is to have a better understanding of VCSEL in terms of strain over at its active region. In addition, the project would also focus on software enhancement and modifications of previous work. The project would touch on the effects of dispersion with different direction ((100) and (110)) and also varying width of the quantum well. The project would touch on optical gain. Lastly, the project would touch on LabVIEW application. Firstly, Dotshape.f90 was a software previously used and was modified to ease the trouble of calculation done manually. The reason is because manual work is very tedious and there is also a high possibility of making human error while dealing with many numbers. With the help of these modifications, user not only can save time and be certain that the results are accurate. After modification of the Dotshape.f90, it was used to help out in strain effects calculation to have a better understanding on strain effects and also lattice-mismatched strain equation on ternary compound materials. Since the lattice constant of the quantum well and barrier region were different, it would be possible to say that there would be a latticemismatched strain. Lattice-mismatched strain was ignored as it would introduce undesirable dislocation at the interface. Results shown that there was compressive strain in the x and y directions while a tensile strain in the z direction. Secondly, effects of Dispersion on different direction was first to look at. Test condition was set with the use of Dotshape.f90. With the results, a data plot would be plotted and it was observed that (100) has more dispersion than (110). After that, the width of the quantum well was varied and the effect of dispersion was observed. It can be observed that with a smaller well width, the energy level will be higher for Conduction band, smaller for Valence band. In addition, Optical Gain was touched on briefly to ensure that TME results were correct and also finding of the energy based on the k value range for calculation of the quantum well optical gain. Thirdly, basic of labVIEW was being touched on. The requirement was to modify and enhance the program that came along with the Keithley 2520INT equipment. The objective was to understand the flow of the program and from the understanding make some enhancement to the program to plot the power vs current curve.