Fiber lasers are lasers which use optical fibers to amplify the power of light, in the form of a light beam. Due to their high power, small form-factor, low weight, high beam quality and robust construction, fiber lasers are the fastest growing segment of the laser market. Bailey Meehan, who is a third year PhD candidate in the Materials Science and Engineering department at Clemson University, deals with fiber lasers and optical fibers everyday and is trying to figure out how to address a growing concern in the fiber laser industry.
In recent years, there has been a plateau in the power output of a fiber laser, owing to complex optical non-linear effects that can cause a variety of problems above certain power levels. These problems can be mitigated using traditional approaches of making larger fibers to spread out the power and retain the intensity within a certain threshold. However, this would require complex fiber designs to sustain proper operation.
Bailey, who works with Dr. John Ballato at the optical fiber fabrication laboratory at Clemson’s Advanced Materials Research Laboratory (AMRL), aims to delve deeper into the fundamental interaction between light and matter and figure out how to solve these problems using standard materials and processes currently used in the industry.
Optical fibers are about the same size as a strand of human hair. Consequently, if one were to fit all the available light into such a micron-sized space, it would result in a brightness over 30,000 times the brightness of the surface of the sun. As such, this would create an extreme environment where a variety of nominally weak parasitic effects can take over and create complications.
“Since these light-matter interactions are nominally weak, we need a high-performing (low-loss) fiber to even reach the powers at which they become problematic”, Bailey said. “This limits us to commercially-acceptable fiber fabrication processes, namely chemical vapor deposition (CVD).” However, the CVD process, introduces a whole host of additional challenges, such as requiring appropriate precursor chemicals, immiscibility of certain dopants and volatility of others.
Therefore, Bailey seeks to primarily understand the process parameters involved in fabricating low-loss optical fibers and learn how these parameters can be used to make glass with desired compositions to combat detrimental optical non-linear effects.
In describing the relevance of his work in today’s life, Bailey states that optical fiber composes the backbone of all the major telecommunications networks used by most people daily. “Specialty fiber has a rapidly growing number of uses in sensing, advanced manufacturing, health and defense”, Bailey said. He further opined that increasing fiber laser output powers would increase the capability and effectiveness of this technology in all these areas.
Throughout his entire life, Bailey has loved science and learning how the world works. He chose to pursue Materials Science as he enjoyed learning chemistry. A requirement to fulfil a research credit led him to being associated with Dr. Ballato’s research group, where he found a suitable fit with his research group as well as the research itself. Growing up as a member of the Clemson community, Bailey has known Dr. Ballato for most of his life.
“A great mentor and communicator, Dr. Ballato ensures that our group is well-organized, well-equipped and held to a high standard”, Bailey said. “He also ensures that we are prepared for life after graduation by teaching us life-skills and things he has learned outside the classroom.”
Bailey is the recipient of scholarships from the Directed Energy Professional Society (DEPS) and Corning Inc. He has presented his research at the DEPS Annual Science and Technology Symposium for the past three years as well as at the American Ceramic Society’s Glass and Optical Materials Division (GOMD) conference during this past year.
In addition to his dissertation work, one of Bailey’s primary responsibilities is to operate the modified chemical vapor deposition (MCVD) lathe, which is a large piece of industrial machinery used to make the extremely-high-purity glass required for low-loss optical fiber. This role has given him the opportunity to collaborate with students and faculty on different projects which has in turn resulted in several co-authored papers. He is optimistic to finish the school year on a positive note, research-wise, and hopes to publish a paper of his own soon.
After graduation, Bailey aims to work in industrial research and development in the field of specialty fiber and fiber lasers. He has his sights set on the industry due to his focus on tangible technology and his desire to deliver products to people that they can actually use. Outside of work, Bailey is an active member of Clemson’s Graduate Student Government as well as the Clemson Wesley Foundation. He also enjoys playing board games, video games, ultimate frisbee and disc golf.
A quote by William Makepeace Thackeray, “Whatever you are, be a good one”, reminds Bailey to be the best version of himself in every facet of his life.
