Laser ablation by GHz bursts of femtosecond laser filaments compared to equal fluence nanosecond pulses

Nanosecond duration envelopes of filamenting femtosecond pulses at GHz repetition rates demonstrate enhanced ablation in silicon and aluminum when compared to temporally Gaussian, nanosecond-duration pulses of similar energy, spot size, and duration. Delivery of energy via bursts of ultrashort pulses avoids significant energy loss due to plasma shielding that occurs for nanosecond pulses at high fluence. Additionally, the temporal structuring of ultrashort pulses allows for a greater deposition of energy to a single point on target than can be achieved by individual ultrashort pulses of equivalent energy due to beam breakup caused by multiple filamentation. This novel structuring of ultrashort pulses into burst modalities provides a step towards enhancing single-shot interactions at standoff distances using nonlinear propagation and filamentation.