Abstract

The beam propagation metnod is perhaps the most widely-used tool in the investigation of optoelectronic structures such as bent waveguides and branching structures. Unfortunately, this method has been notoriously weak in dealing with structures that allow radiation loss, since that radiation tends to reflect from the problem boundaries back into the solution region. The most common way of dealing with this problem (artificial absorbers¹) has a number of well recognized drawbacks, the most serious being the large variability in absorption parameters from problem to problem. In this paper I will describe a new boundary condition algorithm that allows radiation to freely escape the problem without appreciable reflection, while prohibiting the flux of radiation back into the problem region. This boundary condition has no adjustable parameters, and does not require the use of extra mesh points or an expanded problem domain.

© 1991 Optical Society of America