Limit of Effective Area for Single-Mode Operation in Step-Index Large Mode Area Laser Fibers

• Published in: Journal of lightwave technology Vol. 27; no. 15; pp. 3010 - 3016
• Main Authors: Ming-Jun Li, Xin Chen, Anping Liu, Gray, S., Ji Wang, Walton, D.T., Zenteno, L.A.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.08.2009; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Bend tests; Bending; Fiber lasers; Fibers; High power fiber lasers; Laser beams; Laser modes; Lasers; Mathematical models; Optical design; Optical fiber amplifiers; Optical fibers; Performance loss; Refractive index; Samarium
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2009.2020682

Step-index (SI) fiber designs are commonly used in achieving large mode area (LMA) and single-mode (SM) operation in fiber lasers. These fibers can either be intrinsically single-moded fibers or few-moded fibers, which can be forced into SM operation through bending. In this paper we evaluate the limitation of the effective area for SM operation by taking into account the effects of practical constraints such as fiber bending loss, laser performance, and fiber mechanical reliability on these LMA fiber designs. It is shown that the effective area of these fibers cannot be arbitrarily scaled up with the size of the fiber core. We also use the modeling result to provide estimated upper limits to the core diameters and corresponding effective areas for conventional SI fiber designs taking into account fiber parameters that are achievable nowadays.