Formulation and Calculation of spontaneous Emission Rate and Coupling Factor in Microcavity Structures

• Main Authors: Jang Wang, 王蕙貞
• Other Authors: Dr.Kuochou Tai
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/80814928955596356805

碩士 === 國立交通大學 === 電子物理學系 === 82 === In this thesis, we study spontaneous emission in slab and cylindrical dielectric waveguides and the coupling factor in micro-cavity, including surface emitting lasers, micro -disk and micro-ring lasers, by numerical simulations. Strong dependence of spontaneous emission rate on the dipole orientation was found. In planar waveguides, the emission for vertical dipoles was essentially inhibited, while the emission for horizontal dipoles falls into the lowest TE mode when thickness of the waveguide is a fraction of optical wavelength. Total spontaneous emission rates are obtained by adding the contribution from waveguide modes and radiation modes. Spontaneous emission factor β, defined as the fraction of total spontaneous emission into the waveguide or laser mode, was also found to depend strongly on the dimension of the structures. For proton-implanted GaAs surface emitting lasers incorporating AlGaAs/AlAs distributed Bragg reflectors, β is 1.85E-3. For micro-ring,β is as large as 0.925. As for micro- disk lasers,the disk diameter is 1 ∼5μm,when β is 0.1∼0.25 .