KEYWORDS: Laser ablation, Laser processing, Parabolic mirrors, Temperature metrology, Coating, Signal processing, Field programmable gate arrays, Signal to noise ratio, Indium gallium arsenide
Laser material micro-processing with high repetition frequencies of laser pulses is able to initiate heat accumulation effects that can decrease processing rate and quality. In order to gain deeper insights into these effects, a temperature measurement system with nanosecond time resolution was developed using infrared detector and a set of parabolic mirrors. For measurement in more industrially relevant processes on larger areas, alternative configurations were developed: measurement through the scan head and multifocus ellipsoidal mirror. This work is initially focused on comparison of advantages and limitations of the developed measurement configurations by signal to noise ratio, field of view and measurable temperature range. The measurement systems were then used for the analysis of polygon scanner based high-speed laser surface texturing of steel and ceramics substrates as a preparation method for thermal spraying of coatings. GHz burst femtosecond laser ablation was analyzed and long-time process monitoring using FPGA hardware analysis was developed and performed for the laser texturing process.
Two kinds of pulsed lasers in Japan and Czech Republic were used to irradiate various sample materials to investigate the surface erosion thresholds under very hazardous environments including nuclear fusion chambers. The first was ArF laser in ILT and the second was XUV laser in IPP. These data were in-cooperated with our former data to build up our material strength data for our succeeding applications of various materials to a variety of fields. As an example, we proposed surface erosion monitors to notice the fusion chamber maintenance times with which the facilities can be protected from the collapses under very severe operation conditions. These kinds of monitors are expected to be useful for future different kinds of mechanical structures not only for the fusion chambers but also various chambers for many purposes. Special upconversion phosphors are also newly proposed to be used as the candidate materials to measure the thermal inputs onto the front surfaces of the armor structures. Optical transparent SiC was also newly tested to enrich our data base for our future diagnostic and protection possibilities.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.