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.
The TAG Lens is an ultra-high speed varifocal device that uses sound to shape light. This novel and unique mechanism of action empowers the TAG Lens to increase the depth-of-field of conventional lens systems or provide user-selectable focal lengths in one simple, computer-controlled device; giving it the ability to meet the demanding requirements of laser-based materials processing and optical imaging applications. Through this SBIR Phase I project, TAG Optics has been able to fundamentally and radically change the design of the TAG Lens to accommodate high optical powers, a direct response to customer needs for materials processing and advanced imaging. The intellectual merit of this work has focused on developing a deep understanding of optical and thermal phenomena that occurs in the TAG Lens when exposed to high powered illumination and has used this knowledge to develop methods of mitigating any adverse effects. Such a study enabled us to not only meet our goal of a 5 fold increase in power capability, but significantly exceed that target. The result is a new product offering, the TAG Lens HP, which can operate in wavelengths from the UV to the IR and can accommodate over 100 W/cm2 in optical power density. In addition, we successfully enhanced the user experience by updating and improving both our driving electronics and software adding much desired functionality and stability, while at the same time creating comprehensive user guides and technical notes to empower wide spread use of the TAG Lens by end users. Developing the TAG Lens HP and associated software, has enabled TAG Optics to broadened its technological and commercial impacts by opening new market verticals. Moreover, the TAG Lens technology has shown the ability to bring a unique dimension to traditional laser manufacturing equipment and other higher power application areas, providing never before seen capabilities in z-scanning and focusing resulting in increased process efficiency in high power applications.
