In a significant advancement for high-power excimer lasers, researchers have developed a robust high-voltage capacitor charging power supply. Capable of operating at 30 kV and delivering a current of 2.03 A, this innovative power supply is centered around an enhanced resonant converter designed to address limitations in existing technologies.
The improved system leverages the stray parameters of high-voltage transformers, turning potential drawbacks into advantages. Central to its design is the introduction of a smaller resonant capacitor (Cp), which enables a dual-pulse rapid charging method during early stages and transitions to single-pulse slow charging as needed. This sophisticated approach not only enhances charging precision but also significantly reduces adverse currents that can jeopardize system performance.
Excimer lasers, which are renowned for their application in precision materials processing due to their high-energy outputs and minimal thermal effects, often require substantial power inputs. The newly designed capacitor charging power supply is tailored to meet these demands effectively. According to the authors of the article, "By slightly increasing the resonant capacitor Cp, the peak factor of the resonant current can be effectively diminished and the charging accuracy can be improved." This statement reflects a core aspect of their findings.
Testing of the prototype on an excimer laser revealed remarkable results: a peak power of 60.9 kW was achieved with a corresponding laser output power of 304.2 W. The research also indicated a significant charging time of just 3.92 ms at 30 kV, with an average charging current of 2.03 A. These metrics appear to bolster the potential of excimer lasers in various high-demand applications, from microelectronics to medical technology.
The team has implemented a protection network designed to mitigate peak reverse voltages associated with discharge processes. Such discharges can otherwise lead to catastrophic failures in high-voltage systems, particularly in excimer lasers. The protection network was shown to effectively reduce reverse peak voltage by approximately 80%, a critical improvement for sustaining operational reliability. "The designed protection network effectively reduces the reverse peak voltage by approximately 80%, thereby enhancing the reliability and extending the lifespan of the high-voltage charging power supply in high-power excimer laser applications," noted the researchers.
In the course of developing this power supply, the researchers faced several engineering challenges, primarily due to the operational stresses imposed by high switching frequencies, high voltage, and high repetition rates. The design relies on advanced technologies to optimize transformer structures and limit parasitic parameters. The results reported in this study are a testament to the careful engineering and innovative methodologies employed to achieve high performance.
The maximum switching frequency achieved within the studies is approximately 30 kHz, matching the demands posed by modern excimer laser applications. Throughout the experiments, findings indicated that an increase in the capacitor by only 10 pF resulted in a 33.9% improvement in charging accuracy—a figure not to be overlooked in precision-based applications.
As the study concludes, these advancements present significant opportunities not only for enhancing the efficiency and accuracy of excimer lasers but also potentially extending their applicability across various fields requiring precise laser operations. Overall, the newly designed high-voltage capacitor charging power supply stands as a pivotal development in the realm of high-power excimer lasers, addressing ongoing challenges while opening up avenues for future innovations.
