Analysis of planar waveguides by perturbation method
One of the important tasks today in the field of communications and information technologies is the ability to provide high-speed data transmission using fiber-optic communication lines. The presence of existing homo- and heterostructures in semiconductor lasers cannot implement this task due to the fact that at high-frequency modulation these structures generate a large number of modes, i.e., wavelengths. As an alternative, distributed feedback lasers (DFB lasers) are used which active medium is similar to a waveguide that includes a periodic structure, namely a grating.