This Small Business Innovation Research Phase I project seeks to create an ultra-high-speed variable focus optical element meeting the robust performance needs associated with laser manufacturing. The ability to change the focal spot location in laser processing is necessary to accommodate the rapid throughput and complex materials shapes and structures generally encountered in industrial manufacturing. However, the state-of-the-art remains slow, mechanically moving lenses, which can lead to increased production times, reduced accuracy, increased system complexity and overall increased cost. Instead, this work proposes a paradigm-shifting approach to variable focus by developing a new type of liquid lens that uses sound to shape and refocus light. In order to implement this rapidly growing, high impact technology in the manufacturing arena, the key challenge is to manage and reduce laser heating of the device which can lead to undesirable optical effects. By using a combination of experimental tests and numerical models we expect to determine the optimum design conditions that minimize heating effects and maximize refractive power of the lens. With the inclusion of passive and active cooling approaches we expect to enable lens operation for production-level laser manufacturing across different power and pulse duration scales.
The broader impact/commercial potential of this project will have significant repercussions in the laser manufacturing industry, an increasingly important industry which is in many ways responsible for the efficiency and economical cost of every day materials and devices. Specifically, this project addresses a technological market need which will reduce the manufacturing cycle, and streamline processes by providing additional control of the laser beam in the z axis without effecting the x and y axis resolution; thereby, improving the manufacturing yield by increasing the precision, and speed of laser manufacturing systems. Improvements in manufacturing yield are incredibly important to both societal and environmental conditions as they lead to a reduction in waste, an increase in the quality of the parts produced, and a reduction in manufacturing costs. Additionally this proposal will increase scientific and technical understanding on how to applying ultra-high speed z-scanning optical devices in high power lasers systems for manufacturing operation. This will not only lead to the incorporation of such devices in already existing systems but more importantly, enable new innovations such as the creation of entirely new manufacturing approaches with increased performance and capabilities.