Abstract
We demonstrate a novel approach to enhance the mode stability through increased effective index difference (Δneff) between the higher-order modes (LP18, LP09 and LP19) of a multimode fiber. Fibers with large diameters have bigger effective mode areas (Aeff) and can be useful for high power lasers and amplifiers. However, a large mode area (LMA) results in an increased number of modes that can be more susceptible to mode coupling. The modal effective index difference (Δneff) strongly correlates with mode stability and this increases as the modal order (m) increases. We report here that the mode spacing between the higher order modes can be further enhanced by introducing doped concentric rings in the core. In our work, we have shown a more than 35% increase in the mode spacing between the higher order modes by optimizing the doping profile of a LMA fiber. The proposed design technique is also scalable and can be applied to improve the mode spacing between different higher order modes and their neighboring antisymmetric modes, as necessary.
Highlights
High power lasers and amplifiers are necessary for many applications in the field of science and technology
We demonstrate a novel approach to enhance the mode stability through increased effective index difference (∆nef f ) between the higher-order modes (LP18, LP09 and LP19) of a multimode fiber
A large mode area (LMA) results in an increased number of modes that can be more susceptible to mode coupling
Summary
High power lasers and amplifiers are necessary for many applications in the field of science and technology. One of the approaches involves the coupling of light from the fundamental mode to a single desired HOM using fiber Bragg gratings and to propagate light in the higher order mode amplifying fiber [9] These techniques provide considerably larger modal areas as well as more stable operation as described above. Modal solutions Use of the higher order mode (HOM) of a multimode fiber (MMF) shows several advantages which includes mode area scaling to control laser high power and dispersion management for ultra-short pulses. Variation of the effective index (nef f ) with the number of mesh elements (N) is shown in Fig. 2 by a solid black line for the higher order LP09 mode. As the trend of nef f with increasing N for different modes is similar, so the accuracy of ∆nef f between two modes with increasing N is greater
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
