Theoretical analysis and fabrication of antireflection coatings on laser-diode facets

Abstract

Reflectivity of an antireflection-(AR) coated laser-diode (LD) facet is analyzed on the basis of a slab waveguide model and an angular spectrum approach. The reflectivities of single- and double-layer AR coatings on 1.55-μm GaInAsP/InP LD's are numerically calculated. Optimum film parameters, such as thickness and refractive index of single-layer AR coating films, are obtained as functions of the active layer thickness. A minimum reflectivity as low as <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1 \times 10^{-4}</tex> was realized using refractive index controlled SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> film as an AR coating for a 1.55-μm GaInAsP/InP buried-heterostructure (BH) LD.