Structural design criteria for polarization insensitive semiconductor optical amplifiers

A study is made of the possibility of realizing polarization independent semiconductor optical amplifiers by operating on waveguide parameters such as active- and cladding-layer thickness, stripe width, etc. The accurate design of antireflection coating has also been considered in a formulation that allows one to consider the stripe width. It is shown that in coated ridge waveguide structures, the carrier effects on the refractive index may allow equal TE and TM gain to be obtained for various values of the gain when the waveguide geometry is designed with accuracy. The performance of a polarization-independent structure is analyzed, showing that the cost of gain equalization is an increase of the excess coupling losses.>