Robust single-mode all-solid multi-trench fiber with large effective mode area

We experimentally demonstrate all-solid 30 and 90 μm core diameter multi-trench fibers. Measurements ensure an effective single-mode operation over a wide range of bend radius in the case of 30 μm core fiber, making it suitable for applications like beam delivery and compact fiber lasers. On the other hand, a 90 μm core fiber ensures an effective single-mode operation and shows good potential for rod-type fiber laser applications. Both fibers were fabricated by the conventional modified chemical vapor deposition process in conjunction with the rod-in-tube technique, hence making them suitable for mass production.