Translator Disclaimer
17 February 2003 Beam profile approach to lens design for fiber optics
Author Affiliations +
Proceedings Volume 4833, Applications of Photonic Technology 5; (2003)
Event: Applications of Photonic Technology 5, 2002, Quebec City, Canada
The common approach to designing multimode fiber coupling lenses is based on fiber end-face imaging. A model, proposed here, deals with beam profiles. Paraxial ray tracing shows that the output of a graded-index multimode fiber has a hyperbolic profile, similar to a singlemode beam. Focusing this beam by a lens is similar to a Gaussian beam focusing. Light focused from a step-index multimode fiber has two waists. Matching their size and NA to fiber parameters is not enough for good coupling: the beam profile should in fact be corrected. The propagation properties of graded-index multimode fiber beams are similar to singlemode beams and differ from step-index multimode fiber beams. The beam profile approach defines these properties, while the imaging approach often fails. A ray model, describing the beam profile, is convenient in computer simulation of lens systems for fiber optics. It visualizes beams in ray-tracing codes such as ZEMAX and allows aberration optimization regarding minimal beam distortion. Gaussian beam diffraction is not an issue, if there is no beam clipping - the ray model is consistent with the traditional wave model. These results are important for correct design of fiber coupling lenses.
© (2003) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Andrew B. Tsiboulia "Beam profile approach to lens design for fiber optics", Proc. SPIE 4833, Applications of Photonic Technology 5, (17 February 2003);


Back to Top