On the analysis of near-and far-field Radiation patterns for longer wavelength Laser diodes (1.3-AND 1.55 μm)

摘要

Analytical approximation of near-and far-field parameters characterizing the TEo mode propagation in symmetric InGaAsP/InP buried-heterostructure (BH) laser waveguides are described. the beam width is approximated within 5.7 percent by analyti- cal formulas covering useful ranges of cavity thickness and refractive index steps. By using a Gaussian approximation for near-field distribution and solving the maximization of the variational integral by extensive numerical calculations using least-mean-square (LMS) method, it is found that the Gaussian region has been extended to the values of normalised waveguide thickness, D<1.5 which was stated earlier as non Gaussian re- gion [1]. The lower bound values of D is obtained as 1.11 for 1.3 μm wavelength and 0.9408 for 1.55 μm wavelength.