Ultra-short sub-1 ps laser pulses are among the most precise energy delivery tools in material processing. There is no diffusional spreading of the absorbed energy from the focal volume during the pulse. High intensity can render any dielectric material into a strongly absorbing one via the nonlinear multi-photon and avalanche ionization, which dynamically tunes the permittivity from dielectric to metallic like. The lateral and axial energy deposition can be precisely engineered and localized to the volume defined by the fraction of the laser focus for most efficient modification: ablation, polymerization, refractive index change, etc. Resolution of this material processing can reach subwavelength scale in all three dimensions. This technique delivers sub-100 nm resolution and has the unique 3D writing/printing capability among nanotechnology tools. The energy deposition and subsequent material modification has a scalar character while light polarization brings a new vectorial control of laser-induced modification.
© 2019 Japan Society of Applied Physics, The Optical Society (OSA)PDF Article