(DURIP) AUTOMATED LASER MICRO-MACHINING FOR HIGH POWER FIBER LASER
Abstract
With this DURIP program, we will extend our world-class facility in advanced optical fibers for multi-kW laser research. The proposed instrument will enable precise micro-machining of silica fiber laser preforms using a dual CO2 CW and 1064 nm femtosecond laser system. This will allow us to process (mill, drill, fuse, cut, etc.) meter long optical fiber preforms for the development of high-power fiber lasers. In this regard, the state-of-the-art glass micro-machining system will produce new classes of preforms with longitudinally varying features which could open up new degrees of freedom for fibers with judiciously engineered three-dimensional optical and thermal properties. Such formidable control of the fiber properties is otherwise impossible to achieve using conventional preform fabrication methods. At the more fundamental level, unravelling fibers with complex compositions is of scientific and technological importance and remains yet a longstanding challenge. Large mode area fibers are nowadays intensely pursued in terms of addressing longstanding issues related to multi-kW sources with pristine single mode emission. In general, by precisely controlling the 2D structure of the waveguides, several classes of large mode area fibers for multi-kW lasers have been demonstrated. However, over the past few years, average power scaling of single mode fiber lasers has been drastically hindered by thermally induced mode instabilities. On the other hand, advancements in fiber fabrication along with thermal mode instability computation capabilities have stimulated a reconsideration of complex fiber structures for high power levels. A such, innovative fiber designs capable of suppressing not only nonlinear effects but also thermally induced mode instabilities are crucial in order achieve profound output power scaling. The prospect of precisely controlling the fiber properties in 3D (starting at the preform stage) could allow one to overcome the limitations for mode area and power scaling of current fiber laser systems. Unfortunately, with current optical fiber preform fabrication methods, one can only engineer the transverse index profile and to some extent the active-doping profile of the glass material. Here, we aim to address the aforementioned issues by developing a nonconventional preform fabrication approach based on laser micro-machining. In general, the proposed system would be composed of the following- Gantry, 1000x500 mm with a 50 mm Z axis, potentially 2 Z axes, 1 for each laser type (location of Zs could be on either side of cross axis). The lasers and optics mount on the Z-axis (granite bridge). 2) On the base, we would mount an A-62x rotary stage on its side mounted at 1 end, to act as a lathe, rotating the glass tube-preform. 3)The glass preform-tube could be 1 cm to 2 cm thick in OD, with an open aperture of greater than 40 mm for the theta stage. The automated laser micro-machining preform manufacturing system will directly support and impact the following ongoing DoD research programs at the College of Optics and Photonics (CREOL) University of Central Florida- AFRL FA8651-18-2-0019, AFRL A8651-18-2-0019, AFOSR FA9550-15-1-0041, ARO W911NF2020125, ARO W911NF1910426, ARO W911NF2020125, ARO W911NF1710553, AFOSR FA9451-20-C-0015. The impact of this facility will be far-reaching and will not only support our ongoing DoD programs, but will also provide DoD laboratories with an innovative source for advanced optical fiber design and fabrication as well as fiber laser prototyping. Being associated with one of the largest graduate optics and photonics schools, this facility will be part of a comprehensive research and educational program in advanced optical fibers, fiber lasers components and high energy lasers. CREOL is considered a principal resource for the next generation of optical and laser scientists and engineers.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 07, 2023
- Source ID
- FA95502210105
Entities
People
- Rodrigo Amezcua Correa
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Central Florida Board of Trustees