Campbell receives grant for EDF research

Jennifer Campbell, a fourth year physics graduate student in professor Peter Dragic’s lab at the University of Illinois Urbana-Champaign was awarded the 2024-2025 Graduate DE Research Grant in High Energy Lasers. This grant comes from the Directed Energy Professional Society and is awarded to graduate students in investigating various forms of high energy lasing systems and defense technologies related to lasing.  

 Campbell focuses on research regarding the material and lasing properties of erbium-doped fibers (EDFs), one of the most commonly used optical fibers for telecommunications and general fiber amplifiers. The optical fibers are constructed using an original Er:Ba nanoparticle doping method. The doping method means incorporating a material– erbium-based nanoparticles– into the core of the optical fiber.  

 Campbell, along with her other Fiber Optics Research and Glass Engineering (FORGE) lab mates, Siyuan Wang, Michael Gachich, and recently graduated Alex Pietros have worked on understanding not only EDFs, but a wide range of optical fibers and lasing materials. Their investigations have demonstrated that these new EDFs are exceeding the capabilities of standard commercial fiber currently available. This project was done in collaboration with Clemson University, as Professor John Ballato’s group makes all the fibers tested. 

 By finding the ideal balance between the number of nanoparticles and distribution of chemical element, Erbium, in the nanoparticle, there is the potential for the EDFs to reach kW level lasing. 

 “...Development on EDFs has slowed down in recent years due to the difficulty of doping fiber cores with high concentrations of erbium…while maintaining the ability to lase or amplify effectively,” Campbell said. “This has prevented EDFs from being able to produce kW-level lasers, which has put it behind alternative rare earth-doped optical fibers (like Yb and Tm).” 

 The goal for this project is to progress toward developing a kW erbium-doped fiber laser. This is an accomplishment that has yet to be consistently achievable in erbium-based lasing systems.  

 “My investigation so far has been to work on finding the nanoparticle solution that produces the fiber with the highest slope efficiency,” Campbell said.  

 By having a higher slope efficiency, the fibers made with the nanoparticle solution are likely to outperform standard commercial fibers that are frequently used today. Measuring slope efficiency is a means for demonstrating the lasing or amplification capabilities of a material, in this case optical fiber.  

 By finding a new method for doping erbium into fiber, there is a potential to exceed records and bring EDFs to the scale that other chemical elements have already achieved. Additionally, this has the benefit of improving telecommunications systems and creating lasers at eye-safer wavelengths. Eye-safe lasers are popularly sought after for military defense as well as medical procedures. 

“Motivated by the quest of achieving new heights in high-power lasing, I am determined to optimize these fibers and set the foundation for scaling to 1 kW of output power,” Campbell said. “My main hope is to continue developing the methods that we have to create an EDF that is commercially viable to produce and apply in both telecom fields and high-power lasing systems.”