Light propagation in the pseudo-paraxial Fresnel approximation

✍ Scribed by Jean-Luc Kaiser; Eric Quertemont; Raymond Chevallier

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 248 KB
• Volume: 233
• Category: Article
• ISSN: 0030-4018
• DOI: 10.1016/j.optcom.2004.01.053

✦ Synopsis

We propose a new extension of the Fresnel approximation in order to treat the propagation of light in systems where the direction of propagation undergoes important changes. This extension is called pseudo-paraxial Fresnel approximation. Like the Fresnel approximation it is only valid when the light beam has a small divergence, however it can be applied to cases where the direction of propagation is substantially inclined with respect to the optical axis and undergoes important changes. We developed this extension with a particular class of applications in mind: iterative calculations in the field of fiber optics. The small dimensions of fiber optics devices require a high degree of accuracy which makes it impossible to use other approximate propagation methods. Rigourous propagation methods, on the other hand, lead to large computing times when used in iterative calculations. Simulation results in the field of fiber optics are presented showing the gain in accuracy with respect to the usual Fresnel approximation and the reduction of computing time with respect to other non-paraxial propagation methods.