Research On The Integration Of The Vertical Cavity Surface Emitting Lasers And The Photonic Structures

With the development of science and technology, we need to meet an increasing demand of data processing and transmitting. In recent years, the number of CPU on a given computer has increased from only one to dozens, which greatly improves the speed of data processing. Now the development of information procession network based on electronic exchange has approached its limitation. In order to improve the information transfer rate, people begin to build all-optical network. Laser source is an important part of all-optical network. Due to its low threshold current, circular beam profiles and high fiber coupling efficiency, VCSEL is widely used in optical interconnection, optical communication and other field as an ideal semiconductor laser source.In the last several decades, with the research of it, the performance of VCSEL has a huge increase. However, the laser divergence angle of traditional VCSEL is 17°~20°. By employing compound optical lens, epitaxial cavity structure, micro-lens or photonic crystal, the laser beam can reduce the laser divergence angle. However, each method contains deficiency. Compound optical lens, epitaxial cavity structure and micro-lens make the system hard to integrate. Introducing photonic-crystal patterns in the top mirror of VCSEL destroys the original DBR layer, decreases the reflectivity of DBR layer, and declines the efficiency of current injection. With the increase of integrated degree of light module, many researchers begin to research about the integration of the VCSEL and optical elements. Nano-photonic structures is a small structure and easy to integrate, which means they are good choices for integration.This thesis mainly discusses the integration of the VCSEL and nano-photonic structures. In this thesis, the theory of FDTD algorithm, the time convolution PML, the basic structure of VCSEL and photonic crystal band are introduced in detail. The relationship between the focusing ability and the shapes of air-hole of photonic crystal or law of air-hole parameters, the integration of 2D or 3D PC lens and VCSEL, and the integration of PC optical fiber and VCSEL have been studied. Our target is that design a nano-photonic structure which can integrate with VCSEL and has a good focusing ability or collimating effect.The research of graded index PC lens show that the PC lenses with square and rectangular air holes and part of the circular air holes have the ability to break though the diffraction limit. VCSEL integrated with 2D or 3D PC can focus laser beam at 1D or 2D space, respectively. By adjusting the period of photonic crystals in the direction of wave transmission, we can find a 3D PC structure which can integrate with VCSEL, focus with greater energy, has small FWHM, has little difference between FWHMs at x and z direction. In the research about the integration of photonic crystal fiber and VCSEL, five main parameters such as the period and radius of peripheral air holes, the thickness of photonic crystal fiber structure, the presence of center air hole and the number of period of air hole have been analyzed. The average divergence angle of the photonic crystal fiber structure with smaller divergence angles and polarization effects.