GHz burst pumped third-harmonic pulses for precise microfabrication of silicon

There is increased interest in ultrashort GHz burst pulses for uses in precise laser microfabrication. Whereas previous works have focused on GHz burst processing at fundamental wavelengths, here we present results for processing with the third harmonics generated from GHz burst pulses. We find that with these pulses, we are able to achieve high-quality microfabrication of silicon with markedly less debris than with traditional non-burst pulses. We then demonstrated debris-free milling of a silicon micro-hemisphere to show how these conditions are particularly favorable for feedback monitored fabrication applications. Such results show the benefits of GHz-burst-pumped third harmonic machining by commercially available laser sources.