Our group is dedicated to developing and exploring advanced fiber laser technology as well as its novel applications.
Fiber lasers are the next generation of lasers, leading to a number of revolutionary advances in industrial, defense and scientific applications. These advances hinge on fiber lasers’ unique power scalability and their suitability for monolithic integration, so that free space optical configurations of conventional lasers are being replaced by optical circuitry consisting of various fiber and micro-optics elements and components.
Our research is organized into three broad thrusts: (i) novel components for fiber lasers, (ii) advanced fiber laser systems, which include exploring performance limits (power, energy, duration, etc.) of fiber lasers as well as exploring novel fiber laser architectures (for example, fiber laser arrays), and (iii) novel applications of fiber lasers (for example, EUV or X-ray generation with fiber lasers).
For example, one of the main efforts over the last several years have been the development of chirally-coupled-core (CCC) fibers as a new way to control modal properties of very large core fibers , such as achieving single-mode operation, controlling nonlinear interactions, modal dispersion, spectral characteristics, etc. This technology, which is critically important for future high power fiber lasers, is currently being commercialized by Arbor Photonics, Inc., a spin-off from the University of Michigan. Another example is chirped volume Bragg gratings (CVBGs), that are being developed in collaboration with Leon Glebov’s team at CREOL (University of Central Florida) and Optigrate, Inc. These gratings represent a solution to a long standing technological problem of achieving compact ultrashort-pulse stretching and compressing devices for high energy and power fiber chirped pulse amplification (CPA) systems.
Our group had demonstrated a number of bench-mark fiber laser power and energy results, many of them were record-breakers at the time. These include demonstration of 810 W of continuous-wave single mode output power from a Yb-doped double clad fiber (power record in 2004), MW peak powers and up to 80mJ from pulsed large-core LMA Yb-doped fiber amplifiers (these pulse energies still constitute current fiber-laser energy record), and 200 W amplified and 130W compressed 350fs duration pulses from a Yb-fiber chirped-pulse-amplification system using CVBGs (currently the highest power for compact compressors).
Currently we are exploring variety of novel fiber laser architectures for future power and energy scaling, primarily based on fiber-laser array combining methods such as spectral combining, self-locked coherent combining (in collaboration with prof. Herb Winful’s group at the University of Michigan), and other beam combining techniques.
We are interested in pursuing new ground in fiber laser applications. One example is our work on developing fiber-laser driven EUV sources of 13.4 nm radiation for Lithography applications. This work demonstrated for the first time that a fiber laser can provide the high intensity nanosecond pulses required for efficiently generating EUV radiation from laser produced plasma (LPP). More recently, in collaboration with prof. Martin Richardson’s group and CREOL (University of Central Florida) we demonstrated 2% efficient 13.4nm generation with realistic Sn-doped droplet sources, thus showing that fiber lasers offer a very promising path towards practical EUV Lithography sources. Another example is our demonstration of the first fiber laser driven hard X-ray (7.48 keV) sources using high-energy fiber CPA system.
In general, our future interests are to further pursue these approaches, as well as new ideas and concepts that would lead to further advances in high intensity science and technology, currently not possible with any other existing laser technology.