Abstract

Understanding the interplay between optical pulse parameters and ultrafast material response is critical in achieving efficient and controlled laser nanomachining. In general, the key to initiate material processing is the deposition of a sufficient energy density within the electronic system. In dielectrics this critical energy density corresponds typically to a plasma frequency in the near infra red spectral region. Creating this density instantaneously with ultrashort laser pulses of few tens of femtoseconds pulse duration in the same spectral region, the penetration depth into the material will strongly decrease with increasing electron density. Consequently, staying below this critical density will allow deep penetration depths.

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